Employment 7. Topographical Anatomy and Operative Surgery of Anterior Femoral
Surface, Leg and Foot. Accesses tî the Femoral, Anterior and Posterior Tibial Arteries. Topographical Anatomy of Posterior Surface of Lower Extremity. Topography of Vasculo-Nervous Bundles. Accesses tî Vessels and Nerves of Posterior Surface of Lower Extremity
HIP
The pelvifemoral region is that area in which the
lower extremity is firmly bound to the pelvis by powerful muscles and ligaments.
For study it can be divided conveniently in the gluteal (hip) region and the
hip joint.
GLUTEAL REGION BOUNDARIES AND SUPERFICIAL
STRUCTURES The gluteal region is roughly quadrilateral in shape and is bounded
above by the iliac crest, below by the gluteus maximus, medially by the lateral
margin of the sacrum and the coccyx and laterally by the tensor fasciae latae
muscle. Iliac Crest and Spine. The iliac crest is palpable
because of its subcutaneous position. If the anterosuperior iliac spine is located
and the fingers then run backward over the iliac crest they reach a definitely
palpable posterosuperior iliac spine at which point the iliac crest
ends. Below this, the posterior border of the innominate bone is continued
vertically for about
FIG. The gluteal region and its
cutaneous nerve supply.
FIG. The gluteus maximus muscle:
(A) the origin and the insertion of the muscle; (B) the muscle outlined on the
pelvifemoral bony framework.
FIG. The structures lying deep to
the gluteus maximus muscle. The muscle has been severed and reflected medially
to expose its deep surface; its nerve and blood supplies are also shown. The
structures associated with the suprapiriformic and the infraperiformic spaces
are shown.
where
it forms a most efficient cushion upon which the body weight presses while in a
sitting posture. The cutaneous nerves are numerous and difficult to
find, but the small arteries which accompany them may act as guides. These
nerves are derived partly from the posterior primary rami and partly from the
anterior primary rami of the spinal nerves. Three twigs arise from the first 3
lumbar nerves, and 3 from the first 3 sacral nerves. From the anterior primary
rami of the spinal nerves are derived the lateral cutaneous branch of the
iliohypogastric, the lateral cutaneous branch of the last thoracic, twigs from
the posterior branch of the lateral cutaneous nerve of the thigh which
terminates over the greater trochanter, branches from the posterior cutaneous
nerve of the thigh and, finally, twigs from the perforating cutaneous branch of
the fourth sacral. The superficial lymph vessels of the gluteal region
join the lateral lymph glands of the superficial inguinal group.
DEEP FASCIA The deep fascia is strongly
attached to the iliac crest. Where it overlies the gluteus medius muscle it
appears as a dense, opaque pearly white sheet. However, when it reaches the
upper border of the gluteus maximus, it splits into 2 layers which enclose the
muscle. Its appearance over the maximus is not thick and opaque, as over the
medius, but in marked contrast appears thin and transparent. It sends septa
into the muscle and thus divides it into coarse bundles. MUSCLES
Gluteus Maximus. This muscle is rhomboidal in shape and is
the most massive in the body; it is also the coarsest, heaviest and strongest
muscle. Being associated with the upright posture of the biped, it is
especially well developed in man. It arises from the posterior part of the
gluteal surface of the ilium, the dorsal aspect of the sacrum and the coccyx,
and the posterior surface of the sacrotuberous ligament. From this extensive
origin the bundles proceed obliquely downward and forward toward the upper part
of the shaft of the femur, but only a part of the muscle is inserted into the
bone. Three quarters of it is inserted into the iliotibial tract; the lower
deep fibers attach to the gluteal tuberosity. It should be noted that the lower
border of the muscle does not run parallel with the fold of the buttock but
crosses it obliquely, being above its medial part and below its lateral part.
The lower border extends from the tip of the coccyx and across the ischial
tuberosity to the shaft of the femur. The tuberosity is covered by the muscle
when one stands erect, but it is uncovered when one sits down. It was not the
plan of the body to have fleshy muscle support weight; therefore, there is a
thick mass of stringy fibrous tissue between the tuberosity and the skin when
one is sitting. The upper border of the muscle may be indicated by a line which
runs parallel with the lower border and extends outward from the
posterosuperior iliac spine to a point
NERVES
AND VESSELS OF THE INFRAPIRIFORMIC AND THE SUPRAPIRIFORMIC SPACES Infrapiriformic
Space. The structures which enter at
the lower border of the piriformis are from lateral to medial, the sciatic
nerve (which hides the nerve to the quadratus femoris), the nerve to the
gluteus maximus (inferior gluteal nerve), the posterior cutaneous nerve of the
thigh, the inferior gluteal artery, the nerve to the obturator internus, the
internal pudendal vessels and the internal pudendal nerve. Sciatic Nerve. This
(L 4, 5; S 1, 2, 3) is the largest nerve in the body; it is broad and flat. As
it appears from under cover of the piriformis it runs downward to the thigh. At
first it lies on the ischium and then crosses successively the gemelli and the
obturator internus, the quadratus femoris and the adductor magnus. The
posterior cutaneous nerve of the thigh passes on the superficial aspect of the
sciatic. The sciatic continues downward deep to the long head of the biceps; in
its course it passes midway between the ischial tuberosity and the greater
trochanter. It is the most lateral structure in the infrapiriformic region,
having a "side of danger" and "a side of safety." Its
lateral side is the "side of safety" along which dissection may take
place without harm. However, its medial side is its "side of danger"
from which branches spring to the hamstring muscles. The inferior gluteal
nerve (L 5; S 1, 2) is the nerve supply to the gluteus maximus muscle.
Arising from the sacral plexus, it enters the gluteal region through the lower
part of the greater sciatic foramen and enters the deep surface of the muscle. The
posterior cutaneous nerve to the thigh (S 1, 2, 3) passes deep to the
gluteus maximus and medial to the sciatic nerve. It is purely sensory and has
been referred to as the "small sciatic" nerve. Its gluteal branch
turns around the lower border of the gluteus maximus, and its perineal branch
passes lateral to the ischial tuberosity to supply the scrotum or the labium
majus. The main nerve continues downward to the middle of the thigh,
subfascially, and ends on the calf. The inferior gluteal artery divides
into numerous terminal branches as soon as it appears beneath the lower border
of the piriformis. These branches are distributed to the neighboring
musculature, and a small branch accompanies the sciatic nerve; it anastomoses
with branches which join the trochanteric and the crucial anastomoses. The crucial
anastomosis establishes a connection between the internal iliac and the
femoral arteries. The cross is formed by horizontal arms
FIG. The piriformis
muscle.
from
the transverse branches of the circumflex femoral artery, the upper limb from
the descending branches of the inferior gluteal artery, and the lower limb from
the ascending branch of the first perforating artery.
The nerve to
the obturator interims, the internal pudendal artery and the pudendal nerve run
only a small part of their course in the gluteal region; the artery lies between
the 2 nerves. They emerge from the pelvis through the greater sciatic foramen,
cross the spine of the ischium and the sacrospinous ligament and enter the
lesser sciatic foramen to disappear from view. The nerve to the obturator
internus is placed most laterally and supplies a twig to the gemellus superior.
The internal pudendal artery with a companion vein on each side crosses the tip
of the spine. Suprapiriformic Space. The structures which enter along
the upper border of the piriformis muscle are the superior gluteal vessels and
the superior gluteal nerves. The superior gluteal nerve (L 4, 5; S I ) passes in the interval between the gluteus medius and
the minimus. It supplies both of these muscles and ends in the tensor fasciae
latae. Therefore, it supplies the 3 abductors and the medial rotators of the
hip joint, namely, the gluteus medius, the gluteus minimus and the tensor
fasciae latae. The superior gluteal artery is a branch of the posterior
division of the internal iliac (hypogastric) artery. As soon as it passes above
the upper border of the piriformis muscle it supplies a superficial branch
which is distributed to the gluteus maximus. The remaining deep branch breaks
up into upper and lower branches which follow the middle and the inferior gluteal
lines in the interval between the gluteus medius and the minimus.
The Glutei
Medius and Minimus Muscles. These
are really two parts of a single muscle, since they are common in shape,
direction of fiber action, nerve and blood supply. Therefore, it is unusual to
find a fascial plane between them, although at times such an ill-defined plane
may be present. The gluteus medius arises from the area between the
middle gluteal line and the iliac crest. Its fibers converge to form a
flattened band, partly fleshy and partly tendinous, which inserts into the
greater trochanter of the femur. A small bursa separates this tendon from the
anterior part of the trochanter. The gluteus minimus is covered by the
preceding muscle. It arises from the gluteal surface of the ilium between the
middle and the inferior gluteal lines, its fibers
converge and become inserted into the anterior surface of the greater
trochanter. It is intimately connected near its insertion with the capsule of
the hip joint and is separated from the trochanter major by a small bursa.
These muscles are supplied by the superior gluteal nerve and arteries. The
tensor fasciae latae muscle (N. superior gluteal, L 4, 5; S 1) arises from
the forepart of the lateral lip of the iliac crest and the subjacent bony
surface and is invested by fascia lata. It lies over the anterior borders of
the gluteus medius and minimus. Its fibers pass downward and backward to become
inserted into the fascia lata a little below the greater trochanter. This part
of the fascia lata is known as the iliotibial band (tract). It is an extensor
of the knee, acting through the iliotibial band and a medial rotator of the
thigh. Two Gemelli and Obturator Internus Muscles.
These muscles constitute a 3-headed muscle plate which occupies the
interval between the quadratus femoris and the piriformis. The obturator internus arises
from almost the entire pelvic surface of the hip bone below the level of the
obturator nerve. It makes a right-angle turn as it passes through the lesser
sciatic foramen and is separated from the margin of the foramen by a bursa. Its
tendon passes across the posterior surface of the ischium and the capsule of
the hip joint to reach the anterior facet on the upper border of the greater
trochanter. The superior gemellus arises from the ischial spine, and the
inferior gemellus from the ischial tuberosity. They are associated with
the upper and the lower borders of the obturator internus tendon,
and the three together have been referred to as the tricipital tendon. The quadratus
femoris is an oblong muscle which is continuous at its origin and insertion
with the adductor magnus. By some it is considered as an upper extension of
this latter muscle, the division between the two not always being clearly
evident. It arises from the lateral border of the ischial tuberosity, passes
laterally and becomes inserted into a rounded prominence on the trochanteric
crest of the femur. Its upper border lies edge to edge with the inferior
gemellus. The 2 gemelli, the obturator internus and the guadratus femoris, are
closely related to the capsular ligament of the hip joint and act as lateral
rotators of the thigh. However, when the thigh is flexed the position of the
greater trochanter is altered so that the piriformis and the obturator internus
and the gemelli become abductors. The nerve supply of the obturator internus
and the superior gemellus comes from the nerve to the abturator internus, but
the inferior gemellus and the quadratus femoris are supplied by the nerves to
the quadratus. The obturator externus muscle is visible in this region,
but it is better to study its origin when the medial side of the thigh is
discussed. It winds backward below the hip joint, its tendon passing obliquely
upward and laterally on the back of the neck of the femur to become inserted
into the trochanteric fossa.
HIP JOINT The
hip joint is an excellent example of the ball-and-socket variety of joints.
Although it does not allow as free a range of movement as that which
FIG. The hip
joint seen in frontal section.
takes
place in the shoulder joint, the loss in this respect is counterbalanced by a
gain in stability and strength. The head of the femur forms the ball; the
acetabulum, which is deepened by the transverse acetabular ligament and the
acetabular labrum, forms the socket.
ACETABULUM AND HEAD OF THE FEMUR The ball
(femoral head) forms two thirds of a sphere. However, this sphere is not
perfect, since it is flattened above where the acetabulum rests most heavily
upon it. It is covered by cartilage over its globoid surface as far as its
junction with the femoral neck.
FIG. The hip
joint. Five different views showing the relations
between the acetabulum, the ligaments, the head of the femur and the synovial
membranes.
A small depression called the fovea capitis is
located a little behind the summit of the head; it lodges the femoral
attachments of the ligamentum teres through which the head receives a small
arterial supply. At birth the proximal end of the femur is entirely
cartilaginous. The neck is ossified by an extension from the diaphysis; as it
forms, it divides the cartilage into two parts. The more proximal of these
parts forms the head. A center of ossification appears in the head early in the
1st year and unites with the neck during the 20th year. The more distal part
forms the greater trochanter, which begins to ossify in the 3rd year and joins
the shaft about the 19th year. In order to increase the power and the mobility
of the inferior extremity, the neck of the femur is inclined to the shaft at an
angle which is about 125° in the adult and 160° in the child. This has been
known as the angle of inclination. The acetabulum lies at the point of
union of the ilium, the ischium and the pubis. This cup-shaped cavity is
deficient below where it forms a gap called the acetabular notch, which
is bridged over by the transverse acetabular ligament and the glenoid
lip, thus being converted into a foramen for the entrance of vessels and
nerves. The remainder of the peripheral part of this cup is horseshoe shaped;
since it articulates with the femur, it is covered with cartilage. The floor of
the acetabulum, which is called the acetabular fossa, is covered by a small fat
pad (haversian) which in turn is covered by synovial membrane. The
acetabular lip (labrum acetabulare, glenoid labrum) is a firm
fibrocartilaginous ring which is fixed to the rim of the acetabulum; it deepens
the cavity of the acetabulum and narrows its mouth. It fits closely on the head
of the femur and has a suckerlike action which exerts an important influence in
retaining it in place. Therefore, although the hip joint has been opened, it is
not easy to pull the head of the femur out of the acetabulum. Both surfaces of the
lip are covered with synovial membrane; its free margin is thin, but at its
attachment at the acetabular ring it becomes much thicker. Inferiorly, where it
bridges the acetabular notch, it is called the transverse acetabular ligament. The
epiphysis of the head of the femur encircles the articular margin and lies
entirely within the synovial capsule. The ilium, the ischium and the pubis
contribute to the articular part of the acetabulum. This synosteosis is
completed about the 16th year.
LIGAMENTS The
capsular ligament is exceedingly strong and surrounds the joint on all
sides. It is attached proximally around the acetabulum and grasps the neck of
the femur distally. The anterior part of the distal attachment occupies the
whole length of the trochanteric line and the roof of the greater trochanter;
it is very firm and strong. Posteriorly, it falls short of the trochanteric
crest by about ½ inch; therefore, its attachment to the neck of the
femur is weak. The fibers of this ligament run in two different directions, the
majority passing obliquely from the hip bone to the femur. However, other
fibers lie at right angles to the oblique ones, and these constitute the zona
orbicularis. They are circular fibers and are more distinct in the
posterior part of the capsule; they encircle the neck of the femur posteriorly
and below but are lost toward the upper and the anterior part of the capsule.
Since the ilium, the pubis and the ischium take part in the formation of the
acetabulum, capsular fibers proceed from each of these bones to the femur; they
are known as the iliofemoral, the pubofemoral and the ischiofemoral ligaments.
These are thickened portions of the capsule which have been given special
names. The iliofemoral, or inverted Y-shaped ligament of Bigelow, is placed
over the front of the joint and is the thickest and most powerful part of the
capsule. It is attached above to the antero-inferior iliac spine immediately
below the origin of the straight head of the rectus femoris. As it passes
downward it divides into two bands which are separated by a narrow interval.
The upper band extends to the upper part of the intertrochanteric line, and the
lower to the lower part of the same line. It is thicker at its sides than in
the middle, which accounts for its "Y" appearance. The thinner
central portion is perforated by an articular twig from the ascending branch of
the lateral femoral artery. This ligament is approximately ¼ inch thick
and is one of the strongest ligaments in the body, its only rival being the
interosseous sacro-iliac ligament. Bigelow has stated that a strain varying
from 250 to
FIG. The
synovial membrane and the zona orbicularis of the hip joint seen from behind.
FIG. Relations
around the right hip joint. The femur has been removed, and the acetabulum
is viewed from the right side.
When one
stands erect with the toes turned out, the articular cartilage on the head of
the femur is directed forward. Its lateral part is protected by the iliofemoral
ligament, and its medial part by the pubofemoral ligament; however, the
intermediate part has no covering ligament; hence, it is the "weak
point" which is commonly perforated. However, passing over this weak point
is the tendon of the psoas muscle which provides some protection. Muscle fibers
do not withstand pressure by underlying bone; therefore, in such locations they
give place to tendons. This is true of the psoas tendon. Furthermore, tendons
which pass over bony prominences require bursae to diminish friction and to
facilitate a free movement. The psoas bursa which commonly communicates with
the joint between the iliofemoral and the pubofemoral ligaments is no exception
to this rule. In front of this tendon lies the femoral artery. The femoral nerve, which is lateral, lies in front of the iliacus muscle;
the femoral vein, which is medial, lies in front of the pectineus muscle.
The synovial membrane lines all parts of the interior of the hip joint
except where articular cartilage or fibrocartilage is found.
FIG. Transverse
section through the right hip joint.
This last
statement is true of all synovial joints. The membrane lines the neck of the
femur completely in front and as far as the obturator externus tendon behind; it
stretches across the acetabular fossa. In front of the femoral neck and below
it, the membrane is thrown into several loose folds which are called retinacula
and in which arteries run onto the neck of the femur. As the membrane protrudes
posteriorly between the free lower border of the fibrous capsule and the neck,
it forms a bursa for the tendon of the obturator externus. Therefore, an
incision made above this tendon usually will enter the joint, but one made
below usually will miss it. The ligamentum teres or ligament of the head
of the femur consists mainly of synovial membrane; it has the form of a
flattened triangular band. It is attached above to the fovea on the head of the
femur, and below it blends with the transverse ligament. Most anatomists believe
that it does not play a major part in holding the femur in the acetabulum. The
Weber brothers showed the importance of the part played by atmospheric pressure
rather than the ligamentum teres. They suspended a cadaver and divided all the
muscles and ligaments around the joint, and the head of the femur did not pull
free. If an opening was made into the acetabulum to allow the entry of air, the
lower limb immediately fell off. On closing the opening with the finger the
limb could again be kept in position. The ligament is tense when the semiflexed
limb is adducted or rotated outward. It acts as a "mesentery," since
it carries an artery to the femoral head. VESSELS The arteries that
supply the hip joint are derived from the gluteal, the circumflex and the
obturator arteries. Wolcott is of the opinion that the anastomosis between the
ligamentum teres vessel, the capsular artery and the nutrient artery of the
shaft does not take place until the ossification of the head of the femur is
practically, if not entirely, completed. At this time the vessels of the three
systems unite by penetrating the thinned-out cartilage area at the fovea, thus
establishing the anastomosis. The ligamentum teres circulation, he believes, is
a closed one in so far as the femoral head is concerned, until such an
anastomosis takes place. NERVES The nerves are derived from the nerves to the
quadratus femoris, the femoral via the nerve to the rectus femoris, the
anterior division of the obturator nerve, and occasionally the accessory obturator
nerve. MOVEMENTS The depth with which the femoral head
enters its socket would have made only flexion and extension possible, but,
owing to the length of the femoral neck, greater freedom of movement is
permitted. Flexion is much greater in the flexed than in the extended
position because in this position the capsule is looser. In full extension the
head of the femur tends to leave the acetabulum, and the articular surfaces may
be separated by 1 or
FIG. Traumatic
dislocation of the hip joint.
with
the anterior abdominal wall. The muscles which produce flexion are the psoas,
the rectus femoris, the sartorius, the pectineus, the anterior part of the
gluteus medius and the minimus.
In extension the
articular surfaces are held in close contact; rotation and abduction are not as
free as in flexion. Extension is limited by the iliofemoral (Bigelow) ligament.
The muscles which produce extension are the gluteus maximus, the hamstrings and
the posterior part of the adductor magnus. Abduction is very slight in
extension, being checked by the "Y" and the pubocapsular ligaments.
It is produced by the gluteus medius, the minimus, the
upper part of the maximus, the tensor fasciae latae and the sartorius. Adduction
is produced by the adductors, the gracilis and the pectineus; it is checked
by the other limb, but, if in flexion, by the "Y" ligament. Rotation.
The extent of rotation is about 90°. Internal rotation is produced
by the anterior part of the gluteus medius and minimus, the tensor fasciae
latae and the iliopsoas and is limited by the ischiocapsular ligament. External
rotation is produced by the obturator externus, the obturator internus, the
gemelli, the piriformis, the quadratus femoris, the posterior parts of the
glutei, the adductors and the sartorius, and in the flexed condition by the
iliopsoas. RELATIONS The relations are the following. Anteriorly,
the psoas and the femoral artery, the iliacus, the femoral nerve, the
pectineus and the femoral vein. 2. Laterally, the rectus femoris
in front of the iliofemoral ligament and the gluteus minimus. 3. Interiorly,
the obturator externus crosses below the head and runs behind the neck of
the femur. 4. Posteriorly, the piriformis, the obturator internus, the
gemelli, the upper border of the quadratus femoris and the sciatic nerve.
SURGICAL
CONSIDERATIONS
TRAUMATIC
DISLOCATIONS OF THE HIP Since the hip is firmly stabilized by the powerful
muscles and the strong capsule which are associated with it, traumatic
dislocations are rather infrequent. The weak point of the joint is at its lower
part where a portion of the acetabular rim is deficient. However, when
dislocations do occur, they may be posterior, anterior or central. In a
posterior dislocation the head of the femur is forcefully pushed against
the posterior part of the capsule which it tears; it then passes upward and
backward and may occupy an iliac or sciatic position. Hence, two types of
posterior dislocations have been described, namely, the iliac variety and the
sciatic variety. In the latter the head of the femur lies below the tendon of
the obturator internus muscle; in the iliac variety the femoral head lies on
the dorsum of the ilium and can be felt in the buttock. The iliofemoral ("Y")
ligament usually is not torn, since it is the strongest part of the capsule,
but the posterior portion of the capsule usually is torn. The sciatic nerve may
be damaged, and the short rotator muscles of the femur, particularly the
obturator internus, also may be injured. In the anterior dislocation the
head of the femur is forced through the inferomedial aspect of the joint and
passes medially and forward; it may come to rest on the obturator foramen
(obturator variety) or may continue still more anteriorly to reach a position
beneath the pubis (pubic variety). In the obturator variety the femoral head
rests on the obturator externus muscle. In the pubic variety the femoral head
is found in front of the horizontal ramus of the pubis opposite the
iliopectineal eminence. The iliopsoas and the pectineal muscles, as well as the
obturator and the femoral nerves, may be injured. A central dislocation of
the head of the femur penetrates through the acetabulum and has been referred
to as the intrapelvic variety. Usually, a radiating type of
fracture of the acetabulum results with a depression of the socket.
FIG. The
anterior approach to the hip joint.
SURGICAL
APPROACHES TO THE HIP JOINT Numerous approaches have
been described for exposure of the hip joint. However, only 4 of these will be
discussed in this section: the anterior, the anterior iliofemoral, the lateral
and the posterior. The anterior approach to the hip joint commences with
a 5-inch or 6-inch skin incision which extends from the anterior superior iliac
spine downward along the sartorius muscle. The superficial and the deep fasciae
are incised, and the upper third of the sartorius and the rectus femoris
muscles are exposed. In this region the superficial circumflex iliac vessels
are seen and may require ligating. The sartorius and the iliopsoas muscles are
retracted medially, and the femoris muscles laterally. This exposes the
anterior capsule of the hip joint. The femoral nerve lies on the medial aspect
of this capsule and should be retracted medially. The capsule is opened in a
longitudinal direction; if greater exposure of the joint is needed, a
transverse incision into the capsule is added at the end of the longitudinal
one. The anterior iliofemoral approach to the hip joint has been
described by Smith-Peterson. This exposes the anterior and the lateral aspects
of the hip joint. The incision commences at about the middle of the iliac
crest, curves forward to the anterior superior iliac spine and then continues
distally and somewhat laterally for about
FIG. The
anterior iliofemoral approach to the hip joint (Smith-Peterson).
The
superficial and the deep fasciae are incised, and the gluteus medius and the
tensor fasciae latae muscles are severed about ¼ inch from the iliac
crest. These muscles are stripped subperiosteally downward and backward. At
times the lateral cutaneous nerve is seen and retracted medially. The capsule
is now exposed and is incised transversely, care being taken to avoid injuring
the iliofemoral ligament which is on the anterior aspect of the capsule. If
greater exposure of the hip joint is needed, the ligamentum teres can be cut,
and the femur rotated externally so that the head of the femur is dislocated.
Rapid closure may be accomplished by replacing the periosteum against the ilium
and suturing the severed muscles to the crest of the ilium. The lateral
approach to the hip joint can be accomplished through a
"U"-shaped incision as described by Oilier. (Watson-Jones described a
lateral approach through a curved incision.) The "U"-shaped incision
commences at the anterosuperior iliac spine, continues distally below the
greater trochanter, across the femur, then posteriorly and upward and ends
midway between the greater trochanter and the posterosuperior iliac spine.
FIG. The lateral
approach to the hip joint.
The gluteus medius muscle is separated posteriorly,
and the tensor fasciae latae muscle anteriorly down to the greater trochanter.
The greater trochanter is removed with an osteotome and, with its attached
muscles, is displaced proximally. The incision is extended posteriorly by
separating fibers of the gluteus maximus muscle so that adequate exposure is
attained. The exposed capsule is incised longitudinally along the superior
surface of the femoral neck.
FIG. The
posterior approach to the hip joint.
The
posterior approach to the hip joint may be accomplished
by means of a posterior curved incision described by Kocher. This incision
begins at the posterosuperior iliac spine, extends outward and downward
THIGH
The thigh extends from the hip to the knee. The
spine of the pubis and the anterosuperior iliac spine, with the inguinal
ligament stretched between these 2 points, is the dividing line between the
thigh and the abdomen. The upper boundary of the thigh posteriorly is the
transverse gluteal fold; the lower thigh boundary has been set at a level 3
fingerbreadths above the base of the patella. The contour is conical and
oblique in a downward and inward direction; this obliquity is more marked in
the female. The muscles stand out boldly in the well-developed male, but in the
female the thigh is rounded more uniformly, due to the greater amount of
subcutaneous fat.
FRONT OF THE THIGH
NERVES,
FASCIA, VESSELS AND LYMPH GLANDS The skin of the thigh is
thicker over the lateral aspect. The cutaneous nerves of the front of
the thigh are: 1. The ilio-inguinal nerve ( L I
) , which is located close to the pubic spine and to the outer side of the spermatic
cord. It supplies the skin of the scrotum and the root of the penis in the
male, as well as that part of the thigh in contact with the genitals. It
supplies the labium majus in the female. 2. The lumbo-inguinal nerve (femoral
branch of the genitofemoral, L 1, 2) is small and supplies a limited area below
the middle of the inguinal ligament. It is a slender nerve and not easily
found. It pierces the deep fascia a little lateral to the saphenous opening. 3.
The lateral cutaneous nerve of the thigh (L 2, 3) appears behind the
lateral end of the inguinal ligament. It divides into anterior and posterior
branches which supply the skin of the lateral aspect of the thighs as far down
as the knee; it helps in the formation of the patellar plexus. The posterior branch
supplies the anterior part of the buttocks. 4. The intermediate cutaneous
nerve of the thigh (L 2, 3) supplies the skin over the anterior aspect of
the thigh by means of lateral and medial branches, which end in the patellar
plexus. 5. The medial cutaneous nerve of the thigh (L 2, 3) supplies the
medial aspect of the thigh and ends in the patellar plexus. The superficial
fascia of the lower limb is the same as that of the body generally.
Therefore, it has 2 layers, a fatty superficial layer of superficial fascia,
which is a continuation of Camper's fascia of the abdomen, and a deep
membranous layer of superficial fascia, which is a continuation of Scarpa's
fascia of the abdomen. The latter is attached to the deep fascia of the thigh
about a finger's breadth below the inguinal (Poupart's) ligament; more
medially, it attaches along a line which runs parallel with and lateral to the
spermatic cord. This line runs from the pubic tubercle to the pubic arch. If
urine or other fluids pass into the anterior part of the perineum, they cannot
encroach upon the medial side of the thigh because of the attachment of the
membranous layer of superficial fascia from the pubic tubercle to the pubic
arch. However, they can ascend between the membranous layer and the deep fascia
of the abdominal wall. Upon reaching the abdominal wall they cannot descend the
front of the thigh because of the connection of the mebranous layer and the
fascia lata (deep fascia). Internal Saphenous Vein. In the superficial
fascia the subcutaneous vessels, the nerves and the lymph glands are found. Of
practical importance is the internal saphenous vein (saphena magna, great or
long saphenous vein). In the thigh it usually is concealed by the surrounding
fat, but it is seen easily in the leg; hence, its name (saphes = easily seen).
This vein originates at the inner side of the dorsal venous arch of the
foot and passes upward in front of the internal malleolus. It continues to
ascend behind the inner border of the tibia as far as the posterior surface of
the internal condyle of the femur. From here it takes
FIG. The thigh.
a
straight upward course along the medial aspect of the thigh to the fossa ovalis
where it empties into the femoral vein (saphenofemoral junction. Entering the
long saphenous vein are 2 veins which run almost parallel with it. One enters
from the antero-external aspect of the thigh and is called the anterior
(lateral superficial) saphenous; the other from the postero-internal aspect
of the thigh is called the posterior (medial superficial) saphenous. Three
additional veins enter the long saphenous; they are the superficial external
pudic, the superficial epigastric and the superficial circumflex
iliac. Each of these is accompanied by its corresponding artery; the
arteries are branches of the femoral artery. Some of the superficial
tributaries may empty directly into the femoral instead of the internal
saphenous vein; therefore, they do not serve as absolute guides; hence, the
femoral vein may be ligated by mistake. At times the term "accessory
saphenous" is seen in many of the standard texts. The term usually seems
to mean a lesser saphenous vein that ends high in the greater saphenous.
Whether this designates a medial or a lateral vein is still not clear. Daseler
and his co-workers have worked extensively in this field and can be referred
to. The valves in the great saphenous vein vary tremendously in number
and are also variably placed. However, according to Kampmeier and Birch, one is
typically located at the mouth of the great saphenous vein. Variations are
present not only in the valves but also in the veins themselves. Some are of
the opinion that the variations in the greater saphenous vein are in direct
relation to the veins entering it at its upper end. The most typical pattern is
described here. As they pass upward, the greater and the lesser saphenous veins
communicate with each other and with the deep veins of the limb. Especially
those of the leg communicate by means of so-called communicating or perforator
veins, which are so arranged that blood normally
passes from the superficial to the deep-set. Incompetence of some of their
valves is regularly associated with varicose veins and, under these conditions,
permits the blood flow to reverse. The superficial external pudic (pudendal)
vessels pass medially over the spermatic cord in the male and the round
ligament of the uterus in the female. The deep external pudic vessels run under
the spermatic cord or the round ligament; the internal pudic vessels reach the
external genitals within the pelvis. The superficial epigastric vessels arise
about
FIG. The
cutaneous nerve supply of the anterior region of the thigh.
FIG. (A) The
internal saphenous vein, (B) The inguinal lymph glands.
FIG. A composite representation of the communicating and the perforating
veins on the back of the leg.
Lymph Glands. In
this region a number of lymph glands will be encountered. They are subdivided
as follows: Superficial Group: 1. An upper
(horizontal) group lies parallel with the inguinal ligament below the
attachment of Scarpa's fascia to the fascia lata. They drain the regions
supplied by the 3 superficial inguinal blood vessels (anterior abdominal wall
below the navel, the penis, the scrotum, the vulva, the vagina, the anus, the
perineum and the buttock).
DEEP FASCIA (FASCIA LATA) The
structures discussed to this point lie in the superficial fascia. Beneath this
is the deep fascia (fascia lata). This fascia attaches above and below to all
the bony and the ligamentous structures available. Above, it is attached
completely around the limb, to the anterior superior iliac spine, the inguinal
ligament, the pubic bone (body), the pubic arch, the ischial tuberosity and the
sacrotuberous ligament. Posteriorly, the fascia lata becomes the gluteal fascia
and is attached to the sacral spines and the iliac crest and ends as the fascia
lata at the anterior superior iliac spine. Below, the fascia lata
attaches to the periosteum of the patella, the medial and the lateral condyles
of the tibia and the head of the fibula. Thus it completely surrounds the thigh
as a tight-fitting sleeve. Posteriorly, it continues as the popliteal fascia.
The fascia lata is much stronger laterally than medially because of the
iliotibial tract which fuses and runs with it. This tract is a conjoined tendon
for the insertion of the gluteus maximus and the tensor fasciae latae into the
deep fascia of the thigh.
FIG. The septa
of the thigh. The 3 main intermuscular septa of the
thigh (lateral, medial and posterior) form fascial compartments for the 3 main
groups of muscles (extensors, flexors and adductors).
The fascia lata provides septa which separate the
various groups of muscles of the thigh. Each septum inserts at the linea
aspera. Thus each group is enclosed in a separate fascial compartment. Since
there are 3 main groups of muscles (extensors, flexors and adductors) there are
3 main septa: 1. The lateral intermuscular
septum separates the extensors from the flexors and extends from the deep
surface of the fascia lata to the femur along the linea aspera as far as the
lateral epicondyle. 2. The medial intermuscular septum separates the
extensors from the adductors. This septum is much thinner than the lateral; it
forms the floor of Hunter's canal. 3. The posterior intermuscular septum separates
the adductors from the flexors. This septum which originates from the deep
surface of the fascia lata is associated with the connective tissue surrounding
the sciatic nerve. There are also separate fascial compartments for the
individual muscles as well as the larger compartments for the muscle groups. Fossa
Ovalis. The fascia lata has numerous small openings for the passage of the
vessels and the nerves and one large opening, the fossa ovalis for the internal
saphenous vein. This opening is not quite as well marked as the average
textbook picture would lead us to believe. Although present and demonstrable,
it may be quite indistinct. It is a little more than
INGUINOFEMORAL (SUBINGUINAL) REGION This region
extends from the inguinal ligament above to the level of the apex of the
femoral (Scarpa's) triangle below. It also includes the area from the tensor
fasciae latae muscle laterally to the pectineus muscle medially.
Femoral
Triangle. The femoral
triangle of Scarpa (femoral trigone) lies directly below the inguinal ligament
which forms its base. Laterally, it is bounded by the medial border of the
sartorius muscle, and medially by the medial border of the adductor longus
muscle. The floor of the triangle is formed, lateral to medial, by the iliacus,
the pectineus and the adductor longus muscles. The adductor longus forms part
of the floor as well as the medial boundary. The roof is formed by the fascia
lata. When the roof of the triangle is removed, the contents, namely, the
femoral nerve, the artery and the vein, become visible.
FIG. The fossa ovalis.
FIG. The femoral
triangle of Scarpa and its contents. The roof (fascia lata) of the
triangle has been removed, and the relations of the femoral nerve and vessels
to the iliac fascia are shown.
The femoral
sheath can be understood by studying the fascial relations in
the false pelvis and following them into the thigh. The fascia which covers the
iliopsoas muscle is the iliopsoas fascia. It extends from the iliac crest
laterally to the pelvic brim medially. The femoral nerve lies behind it, but
the femoral vein and artery lie upon it. The iliopsoas muscle and its fascia
pass behind the inguinal ligament on their way to the thigh. The iliac part of
the fascia comes in direct contact with the inguinal ligament since no
structures intervene; however, that part of the fasciawhich covers the psoas
muscle cannot touch the inguinal ligament because the femoral artery and vein
lie on the fascia, separating it from the ligament. The femoral vessels thus
leave the pelvis and enter the thigh, and the psoas fascia continues behind the
vessels to become continuous with the pectineus fascia. It has been stated that
the fascia lata "takes its origin" from the inguinal ligament; hence,
the iliac part of the iliopsoas fascia fuses with the fascia lata, but it is
impossible for the psoas part of the fascia to touch the fascia lata because of
the interposed femoral artery and vein. Therefore, the fascia lata lies in
front of the vessels, and the continuation of the iliopsoas fascia (pectineus
fascia) lies behind them. The femoral vessels (not the nerve) are thus wrapped
in a downward prolongation of the extraperitoneal fatty areolar tissue which
becomes the femoral sheath. The anterior wall of this sheath is formed by a
continuation of transversalis fascia; this lines the deep surface of the
anterior abdominal wall. The posterior wall of the sheath is formed by that
part of the iliopsoas fascia which lies behind the femoral vessels. The sheath
ends about 1 ½ inches below the inguinal ligament by blending with the
adventitial coats of the femoral vessels. Two anteroposterior septa divide the
sheath into 3 compartments. Separate longitudinal incisions may be made over
each compartment to identify the contents. The femoral artery occupies the
lateral compartment, the femoral vein occupies the
middle compartment, and in the medial compartment, also called the femoral
cana, are found the main lymph vessels of the lower limb. The femoral
artery, a continuation of the external iliac artery, bisects the inguinal
ligament (midinguinal point) and is therefore the ventral structure running
through the femoral triangle. To locate the nerve to the pectineus muscle
{femoral nerve) one must retract the femoral artery medially and the
femoral nerve laterally. It is of fair size and descends downward and inward to
disappear deep to the femoral artery or between it and the deep femoral artery.
This is the only motor nerve that crosses the femoral artery in Scarpa's
triangle, and since it does so posteriorly it is in a protected position.
FIG. The femoral
sheath.
Branches
of the Femoral Artery. Several superficial branches
arise from the femoral artery. The superficial circumflex iliac and the
superficial epigastric arteries have been described. The superficial external
pudendal passes medially in front of the femoral vein and then crosses to the
spermatic cord. The deep external pudendal artery arises a little over
FIG. The femoral
sheath and its associated structures as seen from below.
FIG. The femoral
artery.
FIG. The
relations of the femoral artery and vein in the femoral triangle.
FIG. The femoral
nerve.
FIG. Femoral hernia.
About
SURGICAL
CONSIDERATIONS
SURGICAL
ANATOMY AND REPAIR OF A FEMORAL HERNIA In a femoral hernia the abdominal
contents enter the femoral ring, pass through the femoral canal and leave
through the fossa ovalis. In so doing, the abdominal contents push the parietal
peritoneum, the extraperitoneal fat and the femoral septum on ahead. The
femoral canal is only about ½ inch in length; therefore, it is more of
an anatomic landmark than a true canal or surgical structure. The femoral
ring has the following boundaries:
Anterior: the
inguinal ligament
Posterior: the
pectineus fascia and muscle
Lateral: the
femoral vein
Medial: the
lateral sharp edge of the lacunar (Gimbernat's) ligament. With these boundaries
kept in mind one readily comprehends the danger of cutting lateral to a femoral
hernia (femoral vein).
Surgical
Repair. The surgical
repair of a femoral hernia may be accomplished through a subinguinal approach
or an inguinal approach. The subinguinal approach usually is performed
through a vertical incision placed directly over the protruding mass. The
incision is deepened until a fatty mass is seen below the fatty areolar layer.
If the falciform margin is well developed it can be severed; otherwise, one
proceeds directly to the femoral ring where the neck of the sac is freed. The
extraperitoneal fat is incised, and the sac (peritoneum) is located and opened.
If the femoral ring is so small and tight that strangulation is produced and
the contents cannot be reduced, more room can be gained by cutting the lacunar
ligament. If viable, the contents are reduced, and the sac is ligated and
excised. The usual method of repair is one in which the inguinal ligament is
sutured to the fascia of the pectineus muscle. The femoral vein must not be
encroached upon. The inguinal approach opens the inguinal canal, as in
the repair of an inguinal hernia. The transversalis fascia is incised, and the
neck of the femoral hernia sac is located in the extraperitoneal fatty layer
just proximal to the femoral ring. The sac is drawn into the inguinal canal; it
is handled in the routine manner. Both the femoral ring and the inguinal canal
are closed by placing sutures which approximate the conjoined tendon and the
inguinal ligament to Cooper's ligament.
LLGATION OF
THE FEMORAL ARTERY IN THE FEMORAL TRIANGLE The femoral artery is situated in a
superficial position in the femoral triangle of Scarpa. The femoral vein lies
in close proximity to the artery. The artery is easily ligated in this location
because of its superficial position and because of the ease with which it can
be separated from the femoral vein, since each vessel is situated in its own
compartment within the femoral sheath. Collateral circulation is maintained
through anastomoses between the superior and the inferior gluteal vessels and
the first perforating branch of the deep (profunda) femoral artery. Ligation of
the artery at the apex of the femoral trigone can be accomplished through an
incision placed directly over the vessel. The sartorius muscle is identified
and retracted laterally; the vessel is isolated just before it enters the
subsartorial (adductor)
MUSCULATURE
OF THE THIGH Since the thigh is capable of performing
4 principal types of movements it is well to consider the musculature in 4
parts:
1. Adductors
(obturator nerve)
2. Abductors
(superior gluteal nerves)
3. Extensors,
anterior femoral muscles, (femoral nerve)
4. Flexors,
posterior femoral muscles, (sciatic nerve).
FIG. The anatomy involved in the
repair of a femoral hernia.
FIG. Exposure
and ligation of the femoral artery in the femoral triangle.
ADDUCTOR (OBTURATOR) GROUP The
adductor region has been referred to as the obturator region, since it is
supplied by the obturator nerve. In this region, which is situated on the
medial aspect of the thigh, are found 6 muscles: 3 adductors (longus, brevis
and magnus) plus 3 other muscles: the pectineus, the gracilis and the obturator
externus. These muscles constitute a group which is interposed between the
extensor group in front and the flexor group behind. The adductor muscles arise
from the bones around the obturator foramen and the obturator membrane;
they insert from the trochanteric fossa of the femur above to the medial
surface of the tibia below. The pectineus muscle can be exposed after
having identified the femoral triangle; it makes up part of the floor of this
triangle. It arises from the superior ramus of the pubis, runs downward and
backward to become inserted into the posterior aspect of the proximal part of the
femoral shaft just below the lesser trochanter. This muscle is peculiar in that
it has a double nerve supply. The medial part is supplied by the obturator
nerve; the lateral half, by the femoral nerve. Because of this, some anatomists
believe that the muscle has a double origin and should be divided into medial
and lateral parts. Although the greater part of the muscle is supplied by the
nerve to the pectineus (femoral nerve), it is still considered one of the
adductors in the obturator group. The adductor longus muscle lies on the
same plane as the pectineus; therefore, it also makes up part of the floor of
Scarpa's triangle. It arises by a flattened tendon from the body of the pubis
in the angle between the crest of the pubis and the symphysis pubis. If the
thigh is abducted, its tendon becomes prominent and palpable and acts as a
guide to the pubic tubercle. Extending downward and laterally, its fibers
spread out into a rather broad thin aponeurosis which inserts into the medial
lip of the linea aspera. It lies between the pectineus and the gracilis. (The
adductor brevis may be seen behind and between the pectineus and the adductor
longus muscles.) It is the most anterior of the 3 adductor muscles. If it is
divided near its origin and turned down, its nerve and blood supply are seen
entering its deep surface. The muscle which is exposed by reflecting the
adductor longus is the adductor brevis. The adductor brevis, a large
muscle, is covered with fat on its anterior surface. In this fat lies the
anterior division of the obturator nerve. (The posterior division of the nerve
lies behind the adductor brevis.) The anterior division of the nerve supplies
the adductor longus and the brevis, the gracilis and the hip joint. Also
running in this fat is the deep branch of the femoral artery (profunda femoris)
with its accompanying veins. The adductor brevis arises from the front of the
pubis below the adductor longus and runs downward, backward and laterally. It
inserts into the linea aspera above and behind the adductor longus, reaching
almost as high as the lesser trochanter. Its upper border lies against the
obturator externus. If the adductor brevis is cut near its origin and turned
downward the adductor magnus is seen. The adductor magnus muscle, largest
and most posterior of the 3 adductors, rises from the inferior ramus of the
ischium and the outer part of the
FIG. The
adductor group of muscles. Six muscles constitute this group: the 3
adductors (longus, brevis and magnus), the pectineus, the gracilis and the obturator
externus.
inferior
surface of the ischial tuberosity. It inserts on the linea aspera extending
upward along the linea aspera's lateral continuation, the gluteal tuberosity,
and downward on its medial continuation, the medial epicondylar line. The fibers
which arise from the ischial tuberosity pass almost vertically downward to
insert by means of a short tendon into the adductor tubercle which is located
on the medial condyle of the femur. At the insertion of the muscle a series of
osseo-aponeurotic openings are formed by tendinous arches which attach to the
bone.
FIG. The obturator
nerve.
FIG. The
adductor magnus muscle and its 4 osseo-aponeurotic openings.
The upper openings, usually
FIG. The
extensor group of muscles. To identify immediately the entire
musculature of the front of the thigh, the letter "N" can be
constructed, using the tensor fasciae latae, the sartorius and the gracilis.
Three muscles lie above the sartorius (iliopsoas, pectineus and adductor
longus), and 3 muscles lie below the sartorius (vastus lateralis, rectus
femoris and vastus medialis).
FIG. The
subsartiorial (adductor)
EXTENSOR (ANTERIOR) GROUP The extensor group of
muscles is the femoral nerve group. This group has been referred to as
the flexors of the hip, but usually they are called the extensors of the knee.
The group consists of the sartorius, the quadriceps femoris, the iliopsoas and
the pectineus. The sartorius muscle is the longest muscle in the body, its
fleshy part usually measuring over
The
subsartorial (adductor)
FIG. The hamstring
muscles.
FIG. The
cutaneous nerve supply of the posterior aspect of the thigh.
FIG. The deeper
structures of the posterior aspect of the thigh.
Before incising the subsartorial fascia in order
to expose the femoral artery, one should endeavor to expose a fine subsartorial
nerve plexus. This lies immediately beneath the sartorius and is formed by
branches of the obturator, the long saphenous and the internal cutaneous
nerves. Once the subsartorial fascia is incised, the most superficial
structures in the canal will be found, namely, the long saphenous nerve, which
crosses the artery from without inward and gives off a small twig to the
subsartorial plexus. To the outer side of the long saphenous nerve another
nerve is found, the nerve to the vastus medialis muscle. The femoral artery is
situated directly beneath the long saphenous nerve. The artery is separated
from the floor of Hunter's canal by the femoral vein. The vein is posterior to
the artery in the upper part of the canal but posterolateral to it in the lower
part. The adductor longus muscle separates the femoral vessels from the
profunda vessels. The femur and the vastus medialis are anterolateral to the
femoral artery, and the sartorius is anteromedial. Near the lower end of the
canal the femoral artery gives off the descending genicular artery (superior
geniculate anastomotica magna). This vessel supplies a superficial branch which
accompanies the saphenous nerve, an articular branch which takes part in the
anastomosis around the knee joint, and muscular
branches. The quadriceps femoris muscle is composed of 4 parts: the
rectus femoris and the 3 vasti (medialis, lateralis and intermedius). The
rectus femoris arises from the ilium, and the 3 vasti arise from the shaft of
the femur. The rectus femoris is placed over the anterior aspect of the thigh
and is quite distinct from the others, except at its insertion. The vasti
clothe the front and the sides of the shaft of the femur and are more or less
blended with each other; therefore, they are difficult to separate. The
rectus femoris is the most superficial of the 4 and lies between the 2
vasti; it covers the vastus intermedius. Since it is the only portion of the
quadriceps which arises from the innominate bone, it acts as a flexor of the
hip joint as well as an extensor of the knee. The rectus arises by 2 heads: a straight
head from the anterior inferior iliac spine and a reflected head which arises
from the impression on the ilium immediately above the acetabulum. The latter
is under cover of the gluteus minimus. The 2 heads unite in front of the hip
joint, and the muscular belly which results passes down in front of the thigh
and inserts into the common extensor tendon. If the gluteus
medius and minimus are displaced backward and the rectus femoris forward, the
hip joint is exposed. By this approach no motor nerves are encountered.
After being crossed by the sartorius, the rectus femoris becomes superficial
and forms a well-rounded elevation in front of the thigh which is seen best when the knee is extended. It is safe to dissect along
the lateral side of the rectus femoris, since its nerve, from the femoral,
enters its medial side. The vastus lateralis arises from the lateral
part of the linea aspera and from its upward lateral continuation (the gluteal
tuberosity), as well as its downward lateral continuation (the lateral
epicondylar line). This muscle is best seen after the rectus femoris has been
severed about its middle and dissected upward and downward. It forms the
greater part of the fleshy muscle mass on the lateral side of the thigh and is
recognized, since its superficial stratum is a glistening aponeurosis. It
overlaps the vastus intermedius and is partly blended with that muscle. It
gains attachment to the patella by means of the common tendon of insertion. The
descending branch of the lateral femoral circumflex artery is accompanied by
the nerve to the vastus lateralis. This then is the best guide to the anterior
border of the muscle. The vastus medialis is intimately connected with
the vastus intermedius, and difficulty may be found in separating the two. It
originates from the medial lip of the linea aspera and from its medial upward
continuation (the spiral line) and its medial downward continuation (the medial
epicondylar line); its lowermost fibers arise from the tendon of the abductor
magnus muscle. The muscle covers the medial surface of the femur. Its lowest
fibers, which run almost horizontally, form the fleshy mass which can be seen
medial to the upper part of the patella in the living. It is inserted into the
common tendon and into the medial border of the patella and, like the vastus
lateralis, gives off a fibrous expansion to the capsule of the knee joint. The
vastus intermedius arises from and covers the anterior and the lateral
surfaces of the shaft of the femur. Although the vastus medialis covers the
medial aspect of the femur, no muscle originates from this surface; hence, the
bone is almost bare. It is a large fleshy muscle covered laterally and medially
by the vastus lateralis and the medialis and is covered above by the rectus
femoris. It is inserted into the deep aspect of the common tendon. The
quadriceps as a whole acts as a powerful extensor of the knee joint, but in
addition to this the rectus femoris part of the quadriceps acts as a flexor of
the hip joint.
The articularis genu consists
of a few of the deepest bundles of the vastus intermedius. It arises from the
front of the femur and is inserted into the synovial membrane of the knee.
Where the common tendon plays across the front of the lower end of the femur a
sesamoid bone (the patella) develops. The portion of the tendon distal
to the patella is called the patellar ligament. The patella does not lie
in front of the knee joint but rather in front of the end of the femur. It is
well to keep the following picture in mind, so that the anterior thigh
musculature may be quickly vizualized:
1. The
"N" arrangement in which the sartorius makes up the oblique line with
3 muscles placed above it (iliopsoas, pectineus and adductor longus) and 3
muscles below it (vastus lateralis, rectus femoris and vastus medialis).
2. The
adductor brevis is located in the interval between the pectineus and the
adductor longus; the adductor magnus is located in the interval between the
longus and the gracilis; the gracilis lies immediately behind and inserts deep
to the sartorius.
FIG. Methods of
measuring the length of the femur.
FLEXOR (POSTERIOR) GROUP The posterior aspect of
the thigh derives its cutaneous nerve supply in the following way: medially, it
is supplied by the anterior cutaneous rami of the femoral nerve; posteriorly, by
the posterior femoral cutaneous nerve; and, laterally, by the lateral femoral
cutaneous nerve. The posterior thigh compartment contains the 3 hamstring
muscles, namely the semimembranosus, the semitendinosus and the biceps femoris.
The compartment also contains the sciatic nerve and its 2 terminal branches—the
tibial and the common peroneal. A hamstring muscle is one that arises from the
ischial tuberosity and inserts into one of 2 bones of the leg; it is supplied
by the tibial division of the sciatic nerve. Although it covers the femur, it
has no attachments to it. The long head of the biceps femoris meets these
prerequisites, but the short head does not; hence, this is an exception to the
rule. It is interesting also to note that the adductor magnus muscle arises
from the ischial tuberosity, inserts onto the tibia
and is supplied by the tibial division of the sciatic nerve; therefore, it
meets the 3 prerequisites of a hamstring and should be considered as such. For
convenience sake, however, it should be discussed with the adductor group.
Since the short head of the biceps femoris does not meet these 3
prerequisites, it is not really a hamstring but belongs to the muscle plate of
the gluteus maximus. It is supplied by the peroneal division of the sciatic
nerve. The long head of the biceps femoris arises from the lower and the
inner impression of the back part of the tuberosity of the ischium by means of
a tendon common to it and the semitendinosus; it also arises from the lower
part of the sacrotuberous ligament. Its 2 heads unite just above the knee joint
to form a common tendon. As the muscle bundles pass downward and medially, they
lie on the surface of the semimembranosus. The common tendon inserts into the
lateral side of the head of the fibula and forms the upper and the lateral
boundaries of the popliteal fossa. The common peroneal nerve descends along its
medial border. In addition to its action as a flexor of the knee joint and
extensor of the hip, it is a lateral rotator.
FIG. The femur
seen from in front. Muscle origins are shown in red; insertions, in
blue.
FIG. The femur
seen from behind. Muscle origins are shown in red; insertions, in blue.
The semitendinosus, so
named for the great length of its tendon of insertion, arises from the lower
and the medial impression of the ischial tuberosity by a tendon common to it
and the long head of the biceps femoris. It inserts into the upper part of the
medial surface of the tibia just below the gracilis muscle. It is a medial
rotator of the tibia on the femur. The semimembranosus, so named for its
membranous tendon of origin, arises by this thick tendon from the upper and the
outer impression on the ischial tuberosity above and lateral to that of the
biceps femoris and the semitendinosus. It passes downward and medially, at
first deep to the conjoined tendon of the biceps and the semitendinosus, and
then is overlapped subsequently by the laterally placed muscles. It inserts on
the medial condyle of the tibia.
Nerves and
Vessels. The sciatic
nerve leaves the pelvis through the greater sciatic foramen, passes through the
gluteal region and the upper part of the thigh. It ends at about the middle of
the thigh by dividing into lateral and medial popliteal nerves. In the thigh
the adductor magnus muscle is anterior to the nerve, and the long head of the
biceps muscle crosses behind it from medial to lateral. It sends branches to the
semitendinosus, the semimembranosus, the long head of the biceps and the
adductor magnus via the medial popliteal nerve. The short head of the biceps
muscle is supplied by the lateral popliteal nerve. Perforating branches of the
profunda femoris artery enter the posterior aspect of the thigh through
openings found in the adductor magnus muscle. These vessels continue
posteriorly to supply the vastus lateralis muscle and the hamstrings. The first
perforating artery enters into the "crucial anastomosis," and the 3rd
and the 4th perforating vessels anastomose with muscular rami from the
popliteal artery.
FEMUR
The femur or the thigh bone is the longest, the
largest and the heaviest bone in the body, being about a quarter of the entire
height of the individual. The femur is more liable to inequality than is the
tibia or the fibula; hence, the relative length of the lower limb is equal in
only 10 per cent of individuals. The measurements of the length of the femur
are taken from the anterosuperior iliac spine to either the adductor tubercle
or the lower limits of the medial condyle (joint line). The upper border of the
patella also has been used as a distal point in measuring this length; but,
since it is movable, it is not as accurate as the other two. The bone consists
of proximal and distal ends and a shaft. The distal end is larger and close to
its fellow femur, but the proximal ends are separated by the width of the
pelvis. The shaft is thinnest in the middle and enlarges toward the ends,
especially distally. PROXIMAL END The proximal end consists of a head, a neck,
the greater and the lesser trochanters, the trochanteric fossa, the
trochanteric line, the trochanteric crest and the quadrate tubercle. Head. The rounded head forms two thirds of a
sphere, which is directed medially, upward and forward and is gripped firmly by
the labrum acetabulare beyond its maximum diameter. Therefore, it is much more
secure in its socket than is the head of the humerus, which forms only one
third of a sphere. In the erect posture the upper aspect of the head is pressed
against the iliac part of the acetabular articular surface. The head is covered
with hyaline cartilage and presents a depression or pit which gives attachment
of the ligament of the head (ligamentum teres); this depression is located a
little below and behind the central point. Neck. The neck of the femur,
about 1 ½ inches long, is triangular in shape; its apex supports the
head of the femur, and its base becomes continuous with the shaft. It is placed
obliquely and unites the head to the shaft and the trochanters. It thickens
toward each end, especially the shaft end, which it joins at an angle of about
125° in the adult, but is more obtuse in the child. This angle is known as the
"vertical neck-shaft angle." Since the neck of the femur is directed
upward, inward and forward, another angulation results which is forward and is
known as the "declination angle"; it is normally of about 12°. Any
alteration of these angles results in deformity and disability. In reality, the
neck of the femur is the medially curved upper extremity of the shaft, but the
presence of the greater trochanter hides this. It is separated from the shaft
by the trochanteric line in front and the trochanteric crest behind. The
trochanteric line presents a roughened edge produced by the attachment of
the powerful iliofemoral ligament. Its upper end is at the front of the greater
trochanter, and its lower end is continuous with a faint ridge called the spiral
line, which winds around the lesser trochanter to the back of the shaft. The
trochanteric crest crosses the posterior aspect of the bone and continues
into the lesser trochanter below. A small rounded tubercle (quadrate) about its
middle gives insertion to the quadratus femoris muscle. The trochanteric
fossa is small and is located at the junction of the posterior part of the
neck and the medial side of the great trochanter; the obturator externus muscle
inserts here. The greater trochanter is a fixed process which lies in
line with the lateral aspect of the shaft and can be felt through the skin
about one hand's breadth below the iliac crest. The muscles attached to it
produce the rotatory movements of the thigh. It should be looked upon as the
traction epiphysis of the gluteus medius and minimus as well as the piriformis,
the obturator internus and externus, and the gemelli. When the gluteus medius
contracts it draws this trochanter upward, medially and backward. Its upper and
posterior borders are free, and its highest point is located at its posterosuperior
angle. The anterior and the lateral aspects of this trochanter would be
continuous with the corresponding aspects of the shaft except for the presence
of a rough line which marks the site of fusion of the trochanter and the shaft.
If a chisel is driven along the upper border of the femoral neck it would
remove the greater trochanter approximately at this rough fusion line. The
lesser trochanter is a blunt-shaped pyramidal process which is directed
backward and medially from the junction of the lower and the posterior part of
the neck of the femur with the shaft; it is not palpable. It gives attachment
to the tendon of the iliopsoas and has been considered the traction epiphysis
for that structure. The quadrate tubercle is an ill-defined protrusion which
is situated about the center of the trochanteric crest; it gives insertion to
the quadratus femoris muscle. The epiphyseal line of the femoral head
corresponds to its articular margin. Anteriorly, the capsule is attached to the
spiral line; therefore, the whole neck is intracapsular. Posteriorly, the
capsule is attached about a finger's breadth medial to the intertrochanteric
crest, the neck being partly intracapsular and partly extracapsular. The
metaphysis is entirely intracapsular. Since the site of election for the
occurrence of bone disease, especially in the young, is in the metaphysis, if
the metaphysis is inside the joint capsule the disease is likely to invade the
joint. On the other hand, if the disease is primarily in the joint it may affect
the shaft of a bone, if the metaphysis is partly within the affected joint.
DISTAL END The distal end of the femur reveals lateral and medial condyles and
epicondyles, a patellar surface, the intercondylar notch and line, the adductor
tubercle and the pit and the groove for the popliteus muscle. The condyles make
up nearly the entire distal end and give it an irregular cuboidal shape. They
coalesce in front but are separated behind by the deep intercondylar notch. The
top of the tibia and the semilunar cartilages of the knee joint articulate with
the posterior surfaces of the condyles when the knee is bent, but with their
inferior surfaces when the knee is straight. The lateral condyle is
broader than the medial. The lateral epicondyle is the eminence which is
situated on the posterior part of the lateral surface of the lateral condyle. A
pit for the origin of the popliteus muscle is below this epicondyle. The
groove for the tendon of the popliteus muscle passes upward and backward
from this pit close to the articular margin. The medial condyle is
farther from the side of the shaft than is the lateral. It is narrower and more
curved. When the shaft is held vertically it projects to a lower level than the
lateral, but in the natural oblique position of the bone the lower surfaces of
both condyles are in the same plane. Immediately behind and above its center
its rough medial surface presents the medial epicondyle to which the
medial ligament of the knee is attached. Immediately above this is the adductor
tubercle for the insertion of the strong tendon of the adductor magnus. The
intercondylar notch is bounded by the opposed surfaces of the condyles and
separates them behind and below. This notch is occupied by the cruciate
ligament. Its floor slopes upward and backward to a horizontal ridge called the
intercondylar line, which separates it from the popliteal surface of the
shaft. The patellar (trochlear) surface is convex from above downward
and concave from side to side; it is situated on the anterior aspect of the
lower extremity and extends farther upward on the lateral condyle than on the
medial.
FIG. The femoral
epiphyseal lines.
It is separated from the articular surfaces of
the tibia by grooves on either side in which the semilunar cartilages of the
knee rest when the joint is fully extended. The patella articulates with it
when the knee is straight but is drawn off when the knee is bent; in the latter
position its margin can be felt through the tendon of the quadriceps. The sides
of the condyles and the adductor tubercles are felt quite easily in the living
person. The epiphysis at the lower end of the femur is represented by an
irregular horizontal line at the level of the upper limit of the articular
surface in front and behind, which crosses the middle of the adductor tubercle.
The capsule may be outlined posteriorly to the articular margin, and laterally
and medially about
SHAFT The shaft or body of the femur is bowed
slightly forward; its middle two thirds are circular on cross section, but its
upper and lower extremities are oblong, the lower border being the larger. In
the erect posture the shaft is oblique, since the distal ends of the femora are
in contact with each other; but the proximal ends are separated by the pelvis
and by the necks of the femora. Each shaft in its middle third reveals
anterior, medial and lateral surfaces which are separated by rather ill-defined
lateral and medial borders; a well-marked posterior border known as the linea
aspera is easily discernible. The linea aspera is a broad rough line
that stands out boldly from the back of the middle two thirds of the femoral
shaft. It bifurcates both above and below into divergent lines. The upper lines
are the spiral line and the gluteal tuberosity; the lower ones are the medial
and the lateral epicondylar lines. The spiral line passes upward and
medially and becomes continuous with the trochanteric line. The gluteal
tuberosity ascends to the side of the greater trochanter where it becomes
continuous with the epiphyseal line. The lesser trochanter projects from a
triangle bounded by these two lines. The medial and the lateral epicondylar
lines descend from the linea aspera to the epicondyle and give rise to the
boundary of a flat triangular area which is limited below by the intercondylar
line. This area is known as the popliteal surface. The medial
epicondylar line turns abruptly so that the adductor tubercle, which is placed
about ½ inch above the medial epicondyle, is easily palpable. The medial
aspect of the shaft is devoid of muscular attachments.
Attachments to the Femur:
To the head: the ligamentum teres
To the neck: the capsule of the hip joint
To the trochanteric line: the iliofemoral
ligament, the vastus lateralis and the medialis
To the trochanteric fossa: the obturator externus
To the greater trochanter: to the medial surface
the obturator internus, the gemelli and the piriformis; to the upper border the
piriformis; to the anterior surface the gluteus medius
To the quadrate tubercle: the quadratus femoris
To the lesser trochanter: the iliopsoas
To the gluteal tuberosity: the gluteus maximus
and the vastus lateralis
To the spiral line: the vastus medialis
To the area between the gluteal tuberosity and
the spiral line from lateral to medial: the adductor magnus, the adductor
brevis, the pectineus and the iliopsoas
To the linea aspera, lateral to medial: the
vastus lateralis and the intermedius from the lateral lip, the lateral
intermuscular septum and the short head of the biceps. From the medial lip, the
adductor magnus, the brevis and the longus: the medial intermuscular septum and
the vastus medialis From the lateral supracondylar
line: the vastus intermedius, the lateral septum, the short head of the biceps,
the plantaris and the lateral head of the gastrocnemius.
From the medial supracondylar line: the adductor
magnus, the medial septum, the vastus medialis, and the medial head of the
gastrocnemius.
From the shaft (anterior and lateral surfaces):
the vastus intermedius and the articularis genu.
From the lateral condyle: the anterior cruciate
ligament of the knee, the popliteus, and the lateral ligaments of the knee.
From the medial condyle: the posterior cruciate
ligament, and the medial ligament of the knee
The fascia lata attaches to both condyles.
FIG. Approach to
the lesser trochanter of the femur.
FIG. Ligation of the superficial
femoral vein: (A) incision and exposure; (B) removal of thrombus by suction;
(C) ligation and division.
SURGICAL
CONSIDERATIONS
FEMORAL VEIN
LIGATION AND THROMBECTOMY Recently, Allen, Linton and others have advocated
interruption of the superficial femoral vein and removal of thrombi. This is
done as a prevention for pulmonary embolism. A skin
incision is made along the course of the pulsating femoral artery on the
involved side. The artery overlies the vein in this region, and when the former
is retracted laterally the superficial femoral vein is exposed. After identifying
the deep femoral vein, the superficial femoral vein is incised, and the
thrombus is removed; then it is ligated and divided.
FIG. The
anterior approach to the shaft of the femur.
APPROACH TO
THE LESSER TROCHANTER OF THE FEMUR Exposure of the lesser trochanter of
the femur is accomplished through an incision which extends from the upper end
of the trochanter midway between it and the midsacral line downward for about 2
or
APPROACHES TO
THE SHAFT OF THE FEMUR The shaft of the femur may be surgically approached
anteriorly, posteriorly, laterally or medially. The anterior approach is
accomplished through an incision which is made over the greater extent of the
femoral shaft in a line situated between the anterosuperior iliac spine and the
middle of the patella. The rectus femoris and the vastus lateralis are
separated along the intermuscular septum. The vastus intermedius is incised in
the line of its fibers until the femur is reached. Subperiosteal dissection
exposes the anterior and the lateral aspects of the femur.
FIG. The
posterior approach to the shaft of the femur.
FIG. The lateral
approach to the shaft of the femur.
FIG. Cross sections of the lateral
and the medial approaches to the shaft of the femur: (A) in the upper third;
(B) in the lower third.
The posterior
approach is accomplished through a long incision which is
placed over the posterior aspect of the thigh in the line of the shaft of the
femur. The posterior femoral cutaneous nerve should be avoided. The long head
of the biceps femoris muscle with the posterior femoral cutaneous nerve is
retracted laterally; the semimembranosus and the semitendinosus muscles are
retracted medially. The sciatic nerve and the popliteal artery and vein are now
identified. The sciatic nerve is retracted laterally and the popliteal vessels
medially so that the adductor magnus muscle and the short head of the biceps
femoris muscle can be stripped subperiosteally from the femur; it is necessary
to ligate the perforating arteries to accomplish this. The posterior two thirds
of the lower aspect of the femoral shaft is thereby
exposed. The lateral approach commences with a longitudinal skin
incision which is placed along a line extending from the greater trochanter to
the external femoral condyle. The iliotibial tract, the vastus lateralis and
the vastus intermedius muscles are divided in the direction of their fibers.
The exposed periosteum is incised longitudinally, freed anteriorly and
posteriorly, thereby exposing the lateral aspect of the shaft of the femur. The
medial approach for exposure of the lower half of the femoral shaft begins
with a skin incision which is placed along the adductor tendon and extends well
above and below the adductor tubercle. The deep fascia is freed, and one
attempts to avoid entering the synovial membrane of the knee joint. The
sartorius muscle is retracted posteriorly, and the tendon of the adductor
magnus muscle is identified. The saphenous nerve is protected as it courses
along the under surface of the femur, neurovascular bundle is retracted
posteriorly. The adductor magnus tendon and the vastus medialis muscle are
retracted anteriorly. At this point the posterior surface of the femur, as it
lies in the popliteal space, is exposed.
FIG. The medial
approach to the lower end of the shaft of the femur.
KNEE
The region that constitutes the knee is bounded above
by an imaginary line drawn around the thigh at a level of approximately
FIG. The popliteal fossa: (A) the
contents; (B) the upper and the lower triangles; (C) the deeper structures.
POPLITEAL (POSTERIOR) REGION This region
corresponds to the posterior aspect of the knee. The popliteal fossa or space
is lozenge-shaped and has a floor, a roof and lateral boundaries. It consists of
an upper (femoral) and a lower (tibial) triangle. The roof of the space is
formed by the deep fascia, which is composed of circularly arranged fibers
acting as a restraining or retinacular ligament for the hamstrings. It is
pierced near its center by the small saphenous vein which passes between the 2
heads of the gastrocnemius muscle; deep to it is the cutaneous branch of the
medial popliteal nerve (tibial). A transverse incision made through this deep
fascia will require little or no suturing, since it approximates itself;
however, a longitudinal incision will gape. The floor of the fossa is formed by
the lower end of the femur, the posterior part of the capsule of the knee joint
and the popliteus muscle with its strong fascia.
The popliteus fascia is
an expansion from the tendon of the semimembranosus muscle, which passes
downward and outward and covers the popliteus muscle. It attaches to the
popliteal line of the tibia. The popliteal vessels lie on it and end at its
lower border. The popliteus muscle arises within the capsule of the knee joint
from the lateral aspect of the lateral condyle of the femur and is inserted
into the posterior aspect of the tibia above the popliteal (soleal) line. Its
tendon of origin passes downward and backward, separating the lateral semilunar
cartilage from the lateral ligament of the joint. It emerges through the
inferolateral aspect of the posterior part of the capsular ligament. It is a
flexor of the leg and also acts as a medial rotator of the tibia when the knee
is flexed. The medial (tibial) popliteal nerve supplies it.
The femoral
(upper) triangle has the semimembranosus, overlaid by
the semitendinosus on its medial side and the biceps femoris muscle on its
lateral side. The tibial (lower) triangle is smaller, and its sides are
formed by the 2 heads of the gastrocnemius muscle, together with the very
variable plantaris muscle which lies laterally.
NERVES AND
VESSELS The contents of the popliteal fossa are
arranged mainly as nerve, vein and artery: 1. The lateral and the medial
popliteal nerves and their branches
2. The
popliteal vein and its tributaries
3. The
popliteal artery and its branches
4. The
posterior cutaneous nerve
5. Fat and
lymph glands
Popliteal
Nerves. The tibial
and the common peroneal nerves are the terminal branches of the sciatic nerve.
FIG. The
anastomosis around the knee joint.
The tibial
{internal or medial popliteal) nerve enters the
fossa at the upper angle lateral to the popliteal vessels, runs a straight
course to the lower angle of the space and is superficial to the vessels. It
lies immediately beneath the deep fascia. In its course through the space it
crosses superficial to the vessels from lateral to medial. It supplies the
muscles of the space, namely, the lateral and the medial heads of the
gastrocnemius, the soleus, the plantaris and the popliteus. Only one of these,
the medial head of the gastrocnemius, lies medial to the nerve. Because of this
anatomic fact it is safer to dissect on the medial side where the nerve has
only one branch. The sural nerve is a cutaneous branch which arises from
the tibial nerve and descends on the surface of the gastrocnemius muscle. It
supplies small branches to the integument of the calf and the back of the leg, and in the lower third is joined by the sural
communicating branch from the lateral (common peroneal) popliteal nerve. The
sural nerve travels in company with the short saphenous vein. Three small
articular branches usually are present; they supply the knee joint. The close
relationship between the tibial nerve and the popliteal vessels explains nerve
involvement and pain in popliteal aneurysm. The common peroneal {lateral or
external popliteal) nerve generally separates from the sciatic at about the
middle of the thigh, enters the popliteal fossa from the lateral side and
passes downward and laterally, closely associated with and appearing from
behind the biceps femoris. It follows the biceps tendon to its insertion and
leaves the popliteal fossa between that tendon and the lateral head of the gastrocnemius.
This relationship is important and must be kept in mind when a biceps tenotomy
is contemplated. The nerve continues downward behind the head of the fibula and
winds around the lateral aspect of the fibular neck to pierce the origin of the
peroneus longus muscle. It ends by dividing into the superficial
(musculocutaneous) and the deep (anterior tibial) peroneal nerves. The common peroneal nerve gives off no muscular branches but does
give a lateral cutaneous nerve of the calf (lateral sural), a sural
communicating nerve (anastomotic peroneal) and usually 3 genicular branches
which accompany the genicular vessels and supply the ligaments and the synovial
membranes of the knee joint.
Popliteal
Vessels. The
popliteal vein is formed by the junction of the anterior and the posterior
tibial veins at the lower border of the popliteus muscle. It ascends through
the popliteal space to the aperture in the adductor magnus muscle, where it
becomes the femoral vein. In its trip through this space it lies superficial to
the artery but crosses it from medial to lateral. The popliteal vein and artery
are bound together by a fascial tube similar to the arrangement in the region
of the femoral artery and vein; hence, neither can be displaced without
interfering with the other. The small saphenous vein {parva) passes over
the calf of the leg superficial to the enveloping fascia but pierces the deep
fascia in the lower part of the popliteal space. It divides into 2 branches:
one enters the popliteal vein, and the other communicates with the great
saphenous vein. The popliteal artery is the continuation of the femoral
artery; it commences at the opening in the adductor magnus. It passes downward
between the condyles of the femur and leaves the fossa at its distal angle to
end at the distal border of the popliteus muscle where it divides into the
anterior and the posterior tibial arteries. It appears to run laterally as well
as downward because of the inclination of the long axis of the femur. In
addition to its terminal branches, the artery gives 3 paired branches which
arise at different levels. They are: 1. The
superior genicular arteries (lateral and medial), which originate at the
level of the femoral condyle and wind around the femur proximal to these
condyles. They are in close contact with the bone and anastomose anteriorly.
2. The
middle genicular arteries enter the knee joint through the posterior
ligament and are chiefly muscular and articular, being distributed to the
gastrocnemii and the intracapsular structures.
3. The
inferior genicular arteries (lateral and medial) wind around the front of
the knee and pass under cover of the tibial and the fibular collateral
ligaments. They anastomose with each other deep to the patellar ligament; they
take place also in the anastomosis around the knee joint. Since no branches are
given off in the upper part of the popliteal artery, this portion is most
accessible for ligation.
The anterior
{deep) relations of the artery are, the popliteal
surface of the femur, the oblique posterior ligament of the knee joint, and the
popliteus muscle covered by its fascia. A rather thick fat pad separates the
artery from the femur, but the vessel lies in direct contact with the oblique
posterior ligament of the knee joint. Posteriorly, the artery is
separated from the fascial roof of the popliteal space by its accompanying
veins and the medial popliteal nerve. The lymph glands of the popliteal
space lie under the deep fascia. They receive the lymph from the skin of the
outer side of the leg and the foot, and from the deep structures of the foot
via the lymph vessels which accompany the anterior and the posterior tibial
vessels. They also receive lymph from the knee joint. All the efferent vessels
from the glands pass with the popliteal vein and then with the femoral vein to
the deep inguinal lymph glands. It should be noted that the corresponding
glands in the upper limb, namely, the supratrochlear, lie superficial to the
deep fascia. A rich vascular anastomosis exists around and above the patella
and on the ends of the femur and the tibia in the region of the knee joint. The
arteries that take part in this anastomosis are the 2 lateral and the medial
genicular branches of the popliteal, the descending branch of the lateral
femoral circumflex artery and the anterior recurrent tibial artery.
Superficially, these vessels are distributed between the fascia and the skin;
the deeper vessels lie on the lower end of the femur and the upper end of the
tibia, supplying the soft tissues around these structures and sending branches
into the interior of the knee joint.
KNEE JOINTS The knee joints constitute a synovial
joint of the hinged variety. It is the largest and the most complicated joint
in the body. Three bones take part in it: the femur, the tibia and the patella.
In the human the fibula is entirely excluded from it. Originally, in primitive
life there were 3 joint cavities in this location, which now have merged into
one. One is situated between the medial condyle of the femur and the tibia, one
between the lateral condyle of the femur and the tibia, and one between the
patella and the femur. These may be referred to as the medial and the lateral
condylar articulations and the patellar articulation. The condylar
articulations are subdivided further into upper and lower parts by the medial
and the lateral menisci (semilunar fibrocartilages). In all positions of this
joint the patella is in contact with the femur, and the femur with the tibia.
These bones do not interlock, and their areas of contact are large; the
ligaments and the surrounding muscles are strong. Therefore, dislocation of
this joint is uncommon.
PATELLA The patella is a small sesamoid bone in
the tendon of the quadriceps femoris. It is roughly triangular in shape, the
inferior angle represents the apex, and the upper border represents the base.
The lateral and the medial borders are rounded. Its anterior surface is easily
felt through the skin, from which it is partly separated by the subcutaneous
prepatellar bursa. The femoral articular surface is divided by a vertical ridge
into a larger lateral and a smaller medial area. Below the articular surface
the bone is roughened and is nonarticular, and the lower half of this area
covers the posterior aspect of the apex. This bone usually begins to ossify
between the 3rd and the 5th years, and the process is usually completed by
puberty. If one stands erect with the feet together and the toes pointed
forward (the anatomic position), it will be noted that the ball of the big
toes, the medial malleoli and the knees of the two sides touch each other; the
tibiae are parallel but the femora are not. The latter are set obliquely;
although in contact at the knee joint, they are separated above by the width of
the pelvis. The rectus femoris and the vastus intermedius are attached to the
upper border (base) of the patella; when they contract they pull obliquely
upward. The vastus medialis and the vastus lateralis are continuous with each
other at their patellar attachments and occupy the space between the rectus
femoris and the vastus intermedius. The vastus medialis is attached to the
upper two thirds of the medial border of the patella and only slightly to its
upper border; the vastus lateralis is attached to the whole length of the upper
border and only slightly to the lateral border. The vastus medialis draws the
patella medially, and the vastus lateralis pulls it upward but not laterally. A
transverse incision above the patella will incise successively the skin, the
fat, the fascia lata, the rectus tendon, the tendons of the vasti lateralis and
the medialis, the tendon of the vastus intermedius, and the synovial joint
capsule. If the quadriceps is relaxed, as when the heel is placed on a chair,
the patella may be moved medially and laterally, and the posterior articular
surface may be palpated. As the position is changed from extension to one of
flexion, one can feel the patella glide laterally onto the under aspect of the
lateral condyle of the femur, thus leaving the trochlea and the entire under
aspect of the medial femoral condyle exposed, except for a tiny strip which
bounds the medial border of the intercondylar notch. This tiny strip
articulates with a vertical facet on the medial part of the posterior surface
of the patella.
LIGAMENTS AND
CARTILAGES Like other movable joints, the knee has a fibrous as well as a
synovial capsule. The capsular ligament is thin, wide and membranous at
the back but thicker and shorter at the sides. It is absent in front, where it
is replaced by the patella, the ligamentum patellae below the patella, and the
tendon of the quadriceps above it. The femoral attachments of the capsular
ligament are to the sides of the condyles about ¼ inch from the
articular margin, to the back of the femur along the inter condylar line and
immediately above the articular margin of the condyles.
FIG. The knee joint: (A) the knee
joint opened and seen from in front. (B) seen from the
medial side; (C) the arrow shows the relations between the septum and the
perforation.
Its tibial attachments are to the posterior
surfaces and the sides of the condyles about ¼ inch below the articular
margin; also to the anterior surfaces of the condyles along the oblique lines
that begin near the articular margins of the sides and pass to the sides of the
tubercle of the tibia. The capsule is strengthened by expansions from
surrounding muscles, which for the most part are closely attached to it.
However, on the anterolateral aspect there is a definite interval which is
occupied by fat, vessels and nerves. The heads of the gastrocnemius and the
plantaris overlie the posterior part of the capsule opposite the femoral
condyles. The medial head is separated from it by a bursa; the lateral head and
the plantaris are partly attached to it; the popliteus, after it emerges
through the capsule, derives some fleshy fibers of origin from it. At the back
of the medial femoral condyle there is usually a hole in the ligament through
which the synovial membrane becomes continuous with the bursa under the medial
head of the gastrocnemius. The tendon of the popliteus perforates the capsular
ligament opposite the lateral condyle of the tibia. The ligament is also
perforated by articular vessels and nerves. The capsule is overlaid by and
incorporated with the tendinous expansions of the lateral and the medial vasti.
FIG. The right knee joint showing
the ligaments, the capsule, the synovial membrane and the relations. The
capsule is colored green; the synovial membrane, blue.
The patellar ligament (ligamentum patellae)
is a strong fixed band about
FIG. The
ligaments and the cartilages of the right knee joint.
tinuous
over the patellar surface with the central part of the common tendon of the
quadriceps femoris; the deep surface is separated from the synovial membrane by
loose fatty tissue called the infrapatellar pad of fat. A bursa also
separates it from the upper part of the tibia. This bursa is crescentic and,
when enlarged or inflamed, has extensions which pass upward along the sides of
the ligament. The lateral ligament of the knee (fibular collateral ligament)
is a rounded cordlike band which is approximately
The semilunar cartilages (menisci) are
2 crescentic plates of fibrocartilage which lie on the circumferential
portion of the articular surfaces of the tibia. They deepen these areas for the
reception of the condyles of the femur; since they are elastic, they act as
buffers which diminish shocks passing up the limbs. Their distal surfaces are
flat, but the proximal are concave for reception of the femoral condyles. In
the fetus, both surfaces of the menisci are covered with synovial membrane,
which helps to attach their peripheral margins to the tibia; but, as the result
of continued pressure, they are devoid of this synovial covering in the adult.
Each cartilage has 2 fibrous extremities, which are called horns; these are
attached to the intercondylar area on the proximal surface of the tibia. The
cartilages are thick toward the circumference of the joint; the lateral
cartilage is a little thicker than the medial. Both thin out toward the center
where they end as a fine, free, concave edge. They do not cover the entire
extent of the condylar surfaces of the tibia. The lateral semilunar
cartilage is nearly circular in outline, and its horns are fixed to the
tibia close together. The anterior horn attaches to the front of the
intercondylar eminence behind the anterior cruciate ligament with which it
blends. The posterior horn attaches to the back of the intercondylar eminence
and in front of the posterior end of the medial cartilage. The peripheral
margin is adherent to the capsular ligament but to a lesser extent than the
medial cartilage; this is due to the fact that the popliteus tendon and its bursal
sheath separate part of the margin from the capsule. As a result of the
presence of this popliteus tendon, the lateral semilunar cartilage is less
fixed in position; therefore, it is able to adapt itself more easily to sudden
twisting movements of the knee joint. The firmer fixation of the medial
semilunar cartilage renders it much more liable to injury. A fibrous band
leaves the posterior horn and passes upward along the posterior cruciate
ligament to become attached to the medial condyle of the femur. This band has
been called the ligament of Wrisberg. It is well to remember that in
flexion and extension the tibia and the cartilages move on the femur, but in
rotatory movements the femur and the cartilages move on the tibia. The
medial semilunar cartilage is "C"- shaped and adapts the upper
surface of the medial condyle of the tibia to the curvature of the medial
condyle of the femur. It is wider behind than in front; while its peripheral
borders are thick, its central border thins out into a
fine edge. Its anterior horn attaches to the anterior part of the intercondylar
area in front of the anterior cruciate ligament; its posterior horn becomes
attached to the posterior part of the intercondylar area in front of the
posterior cruciate ligament. Its periphery is adherent to the capsule and
therefore to the medial ligament of the knee. The transverse ligament of the
knee is a fibrous band which stretches across the anterior part of one
semilunar cartilage to the corresponding part of the other. By means of this
connection the movements of one cartilage are partly controlled and partly
accompanied by the other. Some authorities believe that the transverse ligament
may be considered the continuation of the peripheral fibers of each meniscus;
the more central fibers attach to the tibia. Therefore, if any force acts on
the periphery of the meniscus while the central part is fixed, it will tear
longitudinally along the line between these inner and outer sets of fibers.
This will result in the condition known as a "bucket handle" tear
of the cartilage. The medial cartilage is the one usually affected. The
relationship of the medial ligament of the knee (tibial collateral ligament) to
the medial meniscus is clinically important. It is responsible for the fact
that injuries to the medial meniscus are more frequent than to the lateral. The
lateral is free to move slightly, but even this slight degree of mobility is
sufficient to provide for its safety. The medial, on the other hand, is fixed
at one point by the tibial collateral ligament; because of this firm fixation,
it is prone to injury. The medial ligament of the knee consists of long and
short fibers; the short ones are on the deep surface of the ligament at its
posterior part and are attached to the margin of the medial meniscus, thereby
binding the meniscus to the tibia. Passing between these 2 sets of fibers of
this ligament is the tendon of the semimembranosus muscle. By this arrangement
the back part of the medial meniscus is firmly fixed. Therefore, excessive rotation
of the femur on the tibia tears the movable front part away from the back which
is firmly anchored. On the nonarticular area of the upper surface of the tibia,
the structures from before backward are: the transverse ligament, the anterior
horn of the medial semilunar cartilage, the anterior cruciate ligament, the
anterior horn of the lateral semilunar cartilage, the intercondylar tubercle,
the posterior limb of the lateral semilunar cartilage, the posterior horn of
the medial semilunar cartilage, and the posterior cruciate ligament. The
coronary ligaments are the deeper portions of the capsule which unite the
semilunar cartilages to the tibia and the femur respectively. Those fibers
which extend to the tibia are shorter, since the cartilages follow the
movements of this bone more closely than those of the femur.
INTERIOR OF
THE KNEE JOINT AND THE SYNOVIAL MEMBRANE When the knee joint is laid open the
semilunar cartilages, the cruciate ligaments and
FIG. The 12 bursae around the knee
joint: (A) lateral view of the right knee joint; (B) posterior view.
the
synovial membrane, including its infrapatellar fold, becomes visible. The
infrapatellar synovial fold (ligamentum mucosum) is the first structure to
be seen. This is a triangular fold of synovial membrane which is pinched
upward. Its apex is attached to the most anterior part of the intercondylar
notch of the femur, and the base extends from below the articular surface of
the patella to the anterior intercondylar area on the tibia. Its sides are prolonged
in a fringelike arrangement which forms the alar folds into
which fat extends. Knee joint injuries may result in bruising of these
fringes. Its base is related to the infrapatellar fat pad which covers the deep
surface of the ligamentum patellae; its borders, the alar folds, remain free. The
synovial membrane lines the capsular ligament but leaves the capsule
posteriorly to pass forward around the cruciate ligament. The complexity of the
synovial membrane may be simplified if we recall that developmentally the joint
possessed 3 synovial cavities: a patellar and 2 condylar. The partition which
separated the condylar from the patellar cavity disappeared, leaving only its
vestigial alar folds. In prenatal life a partition called the intercondylar
septum exists which separates the condylar cavities from each other. The lower
border of this septum is attached to the intercondylar area on the upper aspect
of the tibia. The posterior half of its upper border is attached to the
intercondylar notch of the femur, and the anterior half of its upper border is
free and extends from the intercondylar notch of the femur to the patella just
below its articular surface. During development a perforation appears in this
septum which extends backward to the anterior cruciate ligament. In this way
the intercondylar septum is divided into an anterior part, the infrapatellar
fold, and the posterior part which is associated with the anterior and the
posterior cruciate ligaments. The infrapatellar fold has been described previously.
After these developmental changes have taken place fluid may pass from one
condylar cavity to the other, either by way of the patellar cavity that is over
the infrapatellar folds or via the hole in the intercondylar septum between the
infrapatellar folds and the anterior cruciate ligament. It will be remembered
that each condylar cavity is divided into upper and lower compartments by the
semilunar cartilages. These two parts communicate around the free concave
borders of the cartilages.
BURSAE Since there were 3 primitive cavities in the knee joint, 3
bursae remain in the adult which communicate these cavities with the joint.
They are the bursae which lie deep to the tendons of the quadriceps femoris,
the popliteus, and the medial head of the gastrocnemius. Suprapatellar
Bursa. The bursa which lies deep to the quadriceps femoris tendon is known
as the suprapatellar bursa. This bursa lies between the anterior surface of the
lower part of the femur and the deep surface of the quadriceps femoris muscle.
It extends about 3 fingerbreadths above the upper border of the patella when
the limb is in extension. It almost always communicates with the knee joint,
and for this reason it is removed in excision of the joint for tuberculosis;
however, it may become shut off from the rest of the joint by adhesions. It
rests on a layer of fat which allows it to glide freely when the knee joint is
in motion. Through apertures in the back of the capsule it often communicates
with bursae under the head of the gastrocnemius and the bursa of the
semimembranosus. The popliteus bursa is situated between the popliteus
tendon and the lateral condyle of the femur. It separates the popliteus tendon
from the lateral semilunar cartilage, the lateral tibial condyle and the
superior tibiofibular joint. This bursa is a tube of synovial membrane, which
is situated around the popliteus tendon similar to the one around the long head
of the biceps at the shoulder joint. It communicates with the knee joint both
above and below the semilunar cartilage; in some instances it communicates with
the superior tibiofibular joint. The gastrocnemius bursa is situated
deep to the medial head of the gastrocnemius muscle. Although this bursa does
not always communicate with the medial condylar cavity, it communicates with a
bursa deep to the semimembranosus. In this way it may bring the semimembranosus
bursa and the knee joint into communication. At times a bursa may exist under
the lateral head of the gastrocnemius muscle. An incision may be extended
upward on the tibia to within ¼ inch of its articular margin and still
not open the synovial cavity except posteriorly where the popliteal bursa lies.
The relationship between the synovial membrane and the cruciate ligaments is as
if the 2 ligaments have pushed into the joint from behind, carrying the
synovial membrane before them. Therefore, the posterior cruciate ligament has
no covering on its posterior aspect, but the anterior cruciate ligament is
covered anteriorly. A small diverticulum of synovial membrane is situated
between the two and acts as a bursa during movements of the knee joint.
Although the synovial membrane lines those portions of the capsular ligament
which lie behind the condyles, it does not come into relation with the middle
part of the deep surface of the posterior ligament, since it is held away from
it by the cruciate ligaments. The posterior cruciate ligament may be exposed
from behind without opening into the synovial cavity; the infrapatellar fold
also may be exposed from in front without entering the cavity. The
infrapatellar fat pad fills the interval between the patella, the femur and
the tibia. It adapts itself to the various forms which that recess assumes
during movements of the joint. It is extra-articular and extrasynovial and is
of a semifluid nature. A parapatellar incision close to the patella encounters
this pad in its thickest portion; if the incision is placed more laterally,
easier access is gained, since only the thin alar folds are encountered. Three
bursae, which communicate with the knee joint, have been discussed already. All
told, however, 12 bursae are situated around this joint: 4 of these are
anterior, 2 posterior, 3 medial and 3 lateral.
The 4
anterior bursae are: 1. The
suprapatellar bursa: this has beenthoroughly discussed with the 3 bursae
which communicate with the joint.
2. The
prepatellar bursa is associated with the condition known as housemaid's
knee. It is subcutaneous and lies in front of the lower half of the patella and
the upper half of the patellar ligament. The term "housemaid" is
used, because in scrubbing the floor the hands rest upon the floor, bringing
the bursae into contact with the ground. This constant rubbing causes an
inflammation known as bursitis. The bursa then becomes large and because of its
weight drops below its normal position.
3. The
subcutaneous infrapatellar bursa is situated between the skin and the lower
end of the ligamentum patellae (front of the tibial tuberosity).
4. The
deep infrapatellar bursa is situated between the deep aspect of the lower
end of the ligamentum patellae and the tibia.
The 2
posterior bursae are located between each head of
origin of the gastrocnemius and the capsule of the joint. They often
communicate with the joint. The bursa which is present between the medial head
of the gastrocnemius and the capsule sends a prolongation between the
gastrocnemius and the semimembranosus muscles. If it is enlarged it forms a
swelling at the inner side of the popliteal space, which is referred to as an
enlarged semimembranosus bursa.
The 3 medial
bursae are: One which separates the sartorius, the gracilis
and the semitendinosus from the tibial collateral ligament. The two others
separate the tendon of the semimembranosus from the tibial collateral ligament
medially and the head of the tibia laterally. The semimembranosus tendon is
placed between the ligament medially and the condyle of the tibia laterally.
The 3 lateral
bursae are: 1. Between the biceps
femoris tendon and the fibular collateral ligament
2. Between the popliteus tendon and the lateral condyle of the
femur
3. Between the fibular collateral ligament and the popliteus
tendon
The nerve supply is
rich around the knee joint. It is supplied by 3 branches each from the femoral,
the lateral and the medial popliteal nerves and an additional twig from the
obturator nerve.
Movements.
Flexion, extension and rotation constitute the active movements at the
knee
joint. Flexion is
accompanied by some degree of flexion of the hip joint; the movements of the
tibia and the femur on one another combine sliding, rolling and rotating
actions. When one is in a resting upright position the knee joints are not
fully extended, and the attitude is maintained by the balanced tone of the
flexor and the extensor muscles. The movement of extension is completed
by a movement of lateral rotation of the tibia on the femur; the latter action
locks the joint and renders all ligaments tense, with the exception of the
anterior fibers of the posterior cruciate ligament. This locking mechanism
enables the fully extended knee to become subjected to severe strains without
becoming injured. Rotation is impossible when the knee is fully extended
and any attempt to produce pure rotation in this position results in injury.
Flexion is accompanied in its initial stages by medial rotation of the tibia on
the femur. When the knee is flexed to a right angle a considerable range of
rotation is allowed, but when it is slightly flexed only a small amount of
abduction and adduction can be produced, provided that the foot is placed on
the ground.
FIG. The
superior and the inferior tibiofibular joints.
TIBIOFIBULAR JOINTS The
fibula articulates with the tibia at both of its ends. Therefore, superior and
inferior tibiofibular joints are formed. The superior forms a small synovial
joint, but the inferior is a syndesmosis. The superior tibiofibular joint is
formed where the head of the fibula articulates with the postero-inferior
surface of the lateral condyle of the tibia. These bones are united by a
capsular ligament. The tendon of the popliteus and its
synovial pouch cross the upper and back part of the joint. The pouch
sometimes is continuous with the synovial membrane of the joint through a hole
in the capsule, and in this way the joint indirectly communicates with the knee
joint. The lateral ligament of the knee and the tendon of the
biceps cross the upper surface of the joint. Some fibers of the biceps
tendon extend to the tibial condyle and thus form an additional ligament for
the joint. Since the uppermost fibers of the extensor digitorum longus and the
peroneus longus arise from the lateral condyle of the tibia, they cross in
front of the joint. It is supplied by twigs from the nerve to the popliteus and
from the recurrent branch of the lateral popliteal (common peroneal) nerve. It
permits gliding movements which take place during the separation and the
approximation of the lower ends of the tibia and the fibula in dorso- and
plantarflexion of the ankle joint.
Inferior
Tibiofibular Joint. These bones
are held together by ligaments which do not enclose a cavity. The joint is
formed between a convex fibular surface and a corresponding concave tibial one.
However, the bones are not in contact with each other because the interosseous
ligament not only binds them but separates them. At times this ligament does
not quite reach the lateral border of the distal end of the tibia, and in such
cases there is a narrow strip above the lateral border which is covered with
cartilage for articulation with the uppermost part of the facet of the lateral
malleolus. This joint is constructed firmly; the strength of the ankle joint
largely depends on its integrity. The antero-inferior and the postero-inferior
tibiofibular ligaments (anterior and posterior liga
FIG. Supracondylar
amputation. (A) A circular incision is placed at the level of the upper
border of the patella. (B) The 4 medial muscular structures have been severed,
and the femoral vessels are identified. (C) The periosteum is incised and
dissected
FIG. Exposure of
the knee joint.
merits
of the lateral malleolus) hide the interosseous ligament. They are strong, flat
bands that pass upward and medially from the front and the back of the uppermost
part of the lateral malleolus to the distal end of the tibia. The posterior
ligament is continuous inferiorly with the transverse ligament. The transverse
tibiofibular ligament is attached along the whole length of the posterior
border of the tarsal surface of the tibia and to the malleolar fossa of the
fibula. Superiorly, it is continuous with the postero-inferior ligament, and
its deep surface is in contact with a facet on the talus. The joint derives its
nerve supply from the anterior tibial nerve and a long filament from the nerve
to the popliteus that descends through the interosseous membrane.
SURGICAL
CONSIDERATIONS
SUPRACONDYLAR
AMPUTATION The author described a supracondylar amputation in 1942. The procedure
is accomplished through a simple circular incision placed on a level of the
upper border of the patella. The internal saphenous vein is isolated and
severed. This acts as a guide to the sartorius muscle. Four structures are
identified and divided over the medial aspect of the lower end of the thigh.
They are: the sartorius muscle, the gracilis tendon, the semimembranosus muscle
and the semitendinosus tendon. Laterally, the tensor fasciae latae and the
biceps femoris tendon are divided. The femoral vessels and the sciatic nerve
are isolated, ligated and divided at the lower aspect of the thigh. The
attachment of the quadriceps femoris muscle to the linea aspera is severed. The
bone is sawed from 2 to
EXPOSURE OF
THE KNEE JOINT Numerous approaches have been described for exposure of the knee
joint; only one approach will be discussed here, since the
others
can be found in any standard text on orthopedic surgery. The procedure herein
described is the anteromedial approach. This is accomplished through a
long incision which begins at the medial border of the quadriceps tendon about
LEG
The 2 bones that are found in the leg are the tibia
and the fibula. These bones furnish attachments for the thigh muscles and the
leg muscles.
The cutaneous nerve supply of
the anterior aspect of the leg is derived from the cutaneous rami of the medial
crural branch of the saphenous nerve and from the cutaneous branches of the
lateral popliteal nerve. The lower lateral aspect of the leg is supplied by the
superficial peroneal nerve. The cutaneous nerve supply of the posterior aspect
of the leg is supplied by the end of the posterior cutaneous nerve of the
thigh, the posterior branch of the medial cutaneous nerve of the thigh, the
cutaneous branch of the lateral popliteal (common peroneal) nerve, branches of
the saphenous nerve and the cutaneous branch of the medial popliteal (tibial)
nerve, which is derived from the sural nerve.
DEEP FASCIA This fascia does not form a complete
investment for the leg; it is absent over the subcutaneous part of the medial
surface of the tibia. It is attached to the anterior border of the tibia, then sweeps laterally and around the front to the back of
the leg, to reach the tibia again at its posteromedial border, where it
attaches. Its strength and density vary in different parts of the leg. By
sending inward 2 partitions which attach to the fibula it divides the leg into lateral,
anterior and posterior compartments. The anterior intermuscular septum attaches
to the anterior border of the fibula and separates the extensor muscles of the
anterior compartment of the leg from the peroneal muscles. The posterior
intermuscular septum is interposed between the peroneal muscles and the muscles
on the back of the leg; it is attached to the posterior border of the fibula. A
deep layer of fascia (lamina profunda) arises from the posterior intermuscular
septum and attaches to the medial border of the tibia. This layer divides the
posterior compartment into a superficial and a deep compartment. In this way,
the 3 muscular compartments are formed. The anterior compartment contains the
extensor muscles and the anterior tibial artery and nerve. The lateral
compartment contains the peroneal muscles and the superficial peroneal nerve.
The posterior compartment contains the flexor muscles and the posterior tibial
vessels and nerve. The deep fascia becomes thinner as it passes toward the
distal part of the leg. In the region of the ankle it again becomes thickened
to form fascial bands. These bands are called retinacula; their function is to
retain the tendons in position when the muscles which move the joint are in
action. The superior extensor retinaculum (transverse ligament) is a
band of fascia about 1 ½ inches wide which stretches across the front of
the leg from the tibia to the fibula. At its medial end the ligament splits to
enclose the tendon of the tibialis anterior muscle. In this way a special
compartment is made which is invested with a synovial sheath for the tendon of
this muscle. To its lateral side, the tendons of the extensor hallucis longus,
the extensor digitorum longus and the peroneus tertius muscles pass behind the
retinaculum in a common compartment. This is not provided with a synovial
sheath. The anterior tibial vessels and nerve lie posterior to the extensor
hallucis longus as they pass behind the retinaculum. The inferior extensor
retinaculum (cruciate ligament) lies distal to the ankle joint. It is a
Y-shaped ligament which extends from the lateral part of the calcaneum mediad
and splits, thus giving it the semblance of the letter "Y". The upper
limb of the Y passes to the medial malleolus, and the lower limb passes to the
deep fascia on the medial side of the foot. The tibialis anterior has a
separate synovial sheath under this retinaculum, as has the extensor hallucis.
The extensor digitorum and the peroneus tertius have a common sheath under the
lower retinaculum.
MUSCLES The muscles of the leg consist of 3
groups: (1) the anterior (extensor) group, all of which are supplied by the
anterior tibial (deep peroneal) nerve; (2) the posterior (flexor) group, all of
which are supplied by the posterior tibial nerve; (3) the lateral peroneal
(evertor) group, which is supplied by the superficial peroneal
(musculocutaneous) nerve. Since the fibula is on a plane posterior to that of
the tibia, the anterior compartment faces laterally as well as anteriorly.
ANTERIOR (EXTENSOR) GROUP (ANTERIOR COMPARTMENT) If
one thinks of the tibia, the large toe and the 4 remaining toes, it would
naturally follow that 4 muscles constitute this group. They are: the tibialis
anterior, the extensor hallucis longus, the extensor digitorum longus and the extensor
tertius. The tibialis anterior (tibialis anticus) arises from the upper
half of the lateral surface of the tibia and from the interosseous membrane.
Its tendon begins at about the middle of the leg and follows the anterior
border of the tibia, crossing the bone directly in front of the medial
malleolus. It passes through the medial compartments of the extensor
retinacula, crosses the ankle joint, the talus and the navicular, and finally
is inserted into the medial aspect of the cuneiform bone and the adjoining part
of the base of the first metatarsal. Its action is dorsiflexion (extension) and
inversion
FIG. Cross sections of the right
leg at its upper, middle and lower thirds.
of
the foot. It is separated above from the extensor digitorum longus and below
from the extensor hallucis longus by a septum of deep fascia which leads to the
cellular interspace; this space contains the neurovascular structures.
The extensor hallucis longus is
the long extensor of the big toe. It is a thin muscle which is placed between
the tibialis anterior and the extensor digitorum longus. Its upper portion is
hidden by the 2 last-named muscles, but as it passes downward, it reaches the
surface between them. It arises from the middle two fourths of the anterior
surface of the fibula and from the interosseous membrane. It is accompanied by
the extensor digitorum longus as it passes behind the upper extensor
retinaculum; in the lower retinaculum it is lined with an independent synovial
sheath. As it passes over the ankle joint, it crosses the anterior tibial
vessels and nerves, so that its tendon comes to lie medial to the dorsalis
pedis artery. It is the only muscle which crosses the phalanx of the great toe
on its dorsal aspect. Its action is indicated by its name – extension of the
great toe; it aids also in dorsiflexion (extension) of the foot. The extensor
digitorum longus muscle arises as a long thin sheath of muscle from the upper
three fourths of the anterior surface of the fibula and the interosseous
membrane. Its tendon passes behind the superior retinaculum and in front of the
ankle joint. It passes under the inferior retinaculum and divides into 4 slips
which diverge from each other to reach the lateral 4 toes. Each tendon inserts
into the middle and distal phalanges of the lateral 4 toes. Each tendon also
receives a tendon of the extensor brevis digitorum, which passes onto the
dorsum of each toe and broadens into a dorsal expansion. This is inserted in a
fashion similar to the dorsal expansion of the fingers. The muscle is an
extensor of the toes and a dorsiflexor of the foot. The peroneus tertius is not
a peroneal muscle but rather is a part of the extensor digitorum longus. It is
small and is not always present. Some anatomists consider it the lowest quarter
of the extensor digitorum longus. It ends in a slender tendon which fails to
reach the toe but gains attachment somewhere along the dorsum of the 5 th metatarsal. The action of this muscle is to dorsiflex the
foot and to aid the true peroneal muscle in eversion.
FIG. The anterior and the
posterior cutaneous nerve supply of the leg.
FIG. The deep fascia of the leg:
cross section showing the 3 compartments.
FIG. The muscles of the anterior
and the lateral groups of the leg: (A) the anterior group; (B) deeper
dissection showing vessels and nerves; (C) the lateral group; (D) deeper
dissection showing vessels and nerves.
Nerves and Vessels.
The anterior tibial (deep peroneal) nerve is one of the two terminal
branches of the lateral popliteal nerve (common peroneal). It arises on the
lateral side of the neck of the fibula under cover of the peroneus muscle,
pierces the anterior intermuscular septum and then usually passes between the
extensor digitorum longus and the fibula to enter the anterior compartment of
the leg. In the upper two thirds of the anterior compartment, it lies very deep
between the muscles, having the extensor longus muscle to its lateral side and
the tibialis anterior to its medial side. In the distal third, where fleshy
muscle bellies give place to tendons, it comes closer to the surface. At first,
the nerve is in front of the interosseous membrane, with the anterior tibial
vessels to its medial side. As it descends, it passes onto the front of the
artery. In the distal third of the leg, the nerve lies on the tibia, with the
vessels usually to its medial side again. The extensor hallucis longus, at
first on the lateral side of the nerve, crosses in front of it and the vessels
just above the ankle; it lies medial to them at the ankle, thus separating them
from the tibialis anterior muscle. The nerve leaves the anterior compartment by
passing downward deep to the anterior annular ligament, where it continues with
the dorsalis pedis artery. It supplies the 4 muscles of the anterior compartment.
The anterior tibial artery begins on the posterior surface of the leg,
where it arises from the popliteal artery at the lower border of the popliteus
muscle. It is accompanied by 2 venae comitantes which run with the artery and
send interlacing veins around it. The artery enters the anterior compartment of
the leg by piercing the upper part of the interosseous membrane. In the upper
half of its course, the vessel is situated deeply, with the nerve lying on the
interosseous membrane between the tibialis anterior and the extensor digitorum
longus. In the lower part of its course, the artery lies on the shaft of the
tibia and is overlapped by the extensor hallucis longus. After passing behind
the superior extensor retinaculum, it becomes superficial in the interval
between the tendons of the extensor hallucis longus and the extensor digitorum
longus. In front of the ankle joint, the artery continues as the dorsalis pedis
artery. Branches of this vessel take part in the anastomoses around the knee
and the ankle joints. A straight line drawn from the medial side of the neck of
the fibula to a point midway between the 2 malleoli marks the course of the
anterior tibial artery.
LATERAL (PERONEAL) GROUP (LATERAL COMPARTMENT)
This group is made up of 2 muscles on the lateral aspect of the leg – the
peroneus longus and the brevis; they are evertors. The peronei fill the lateral
crural compartment and are separated from the extensor flexor compartment by
die anterior and the posterior intermuscular septa, respectively.
The peroneus longus arises
from the upper two thirds of this compartment, and the peroneus brevis from the
lower two thirds, thus overlapping each other in the middle third. Both muscles
pass downward, the brevis being covered by the longus, until they reach the
posterior aspect of the lateral malleolus, where the tendon of the brevis is in
direct contact with the bone. Here, the tendons are held down by a thickening
of the deep fascia, the superior peroneal retinaculum. They are provided with a
common synovial sheath. They continue to pass below the malleolus and lie on
the lateral aspect of the calcaneum, becoming separated from each other by the
peroneal tubercle. At this point, they are held in place by the inferior
peroneal retinaculum, and here each possesses a synovial sheath of its own. The
tendon of the peroneus brevis passes above the tubercle to be inserted into the
dorsal aspect of the tubercle on the base of the 5th metatarsal
bone. The tendon of the peroneus longus passes below the peroneal tubercle,
medial and forward across the sole of the foot to become inserted into the
lateral aspect of the medial cuneiform and the adjoining part of the base of
the first metatarsal bone.
Both of these muscles are supplied by the
musculocutaneous (superficial peroneal)
nerve. Actions. When the foot is off the ground, the
peroneal muscles produce eversion. A most important function of the peroneus
longus is to maintain the transverse arch of the foot. By their ability to draw
the foot to the lateral side, the peroneal muscles balance the medial pull
exerted by the tibialis posterior and the long flexors of the toes. The
musculocutaneous {superficial peroneal) nerve arises from the lateral
popliteal nerve on the lateral side of the fibular neck. It proceeds downward
and forward in the substance of the peroneus longus muscle and then between the
peroneus brevis and the anterior intermuscular septum.
FIG. The
superficial posterior group of calf muscles. (A) The relations of the
plantaris, the gastrocnemius and the soleus are shown. (B) The 2 heads of the
gastrocnemius have been cut to show the plantaris tendon and the soleus muscle.
At the junction of the middle and the lower
thirds of the leg, it passes through the deep fascia to become cutaneous. Plus
its muscular and cutaneous branches, it gives off a communicating branch on the
dorsum of the foot to the sural nerve. The anterior border of the peroneus
brevis acts as a guide to this nerve, since it travels with it to the surface,
a variable distance above the subcutaneous area of the fibula.
POSTERIOR (FLEXOR) GROUP (POSTERIOR COMPARTMENT)
This group of muscles is supplied by the posterior tibial nerve, which also has
been referred to as the tibial nerve and as the medial popliteal nerve. The
muscles are divided into superficial and deep groups. The superficial
muscles are the gastrocnemius, the plantaris and the soleus; they
FIG. The superficial
and the deep groups of the calf muscles: (A) the superficial group consists of
3 muscles; (B) the deep group consists of 4 muscles.
join
to form the stout tendo calcaneus, which is inserted into the back of the
calcaneus The gastrocnemius arises from the femur by 2 heads. The medial
head arises from the back of the femur above the medial condyle; the lateral
head arises from the lateral aspect of the lateral condyle. There is an
asymmetry between the origins of these 2 heads. This muscle accounts for the
fullness of the calf, since the 2 muscle bellies broaden as they descend. The
muscle bellies do not blend with each other but are separated by a groove in
which the sural nerve and the short saphenous vein are found. The lateral head
often contains a small sesamoid bone called the fabella, which usually is noted
on the x-ray film opposite the lateral condyle. The common tendon of the 2
heads joins the tendon of the soleus to form the tendo calcaneus; this takes
place a short distance below the middle of the leg. The muscle acts as a
plantar flexor of the foot and as a flexor of the knee. The soleus has a
rather extensive horseshoe-shaped origin from the upper third of the posterior
aspect of the fibula and from the soleal line on the back of the tibia. In its
upper half, this muscle is covered by the bellies of the gastrocnemius, but
where the common tendon of the latter begins, the belly of the soleus projects
beyond its margins, becoming superficial. The tendon of this muscle develops on
its superficial aspect and joins the deep surface of the tendo calcaneus. It is
a plantar flexor of the foot. The plantaris is a small muscle about 3 or
FIG. The
posterior tibial nerve and the posterior tibial and peroneal arteries.
tendon
pierces the posterior part of the capsule of the joint, and its fibers fan out
to obtain insertion into the posterior aspect of the tibia above the soleal
line. It is mainly a flexor of the knee joint. A strong fascia covers the
posterior surface of the popliteus muscle; this tendon can be traced upward and
medially to the medial side of the knee, where it becomes continuous with the
tendon of the semimembranosus. The flexor hallucis longus is the long
flexor of the big toe. It arises chiefly from the posterior surface of the
fibula, below the origin of the soleus. The muscle belly is bulky and overlaps
and largely conceals the fleshy part of the tibialis posterior. At the ankle
joint, it passes through a separate space in the laciniate ligament, being
separated from the flexor digitorum longus by the tibial nerve and the
posterior tibial vessels. It inserts into the terminal phalanx of the great toe
and is a powerful invertor as well as a flexor of the big toe.
FIG. The tibia
and the fibula seen from in front. The muscular origins are presented in
red; the insertions, in blue.
The flexor digitorum longus arises
from the posterior surface of the tibia, below the popliteus muscle and medial
to the vertical ridge. After passing through the split tendon of the flexor
brevis muscle, it inserts into the terminal phalanges of the 4 outer toes. It
flexes the toes, draws the pillars of the arches of the foot together and also
supports the arch. The tibialis posterior muscle originates from the
interosseous membrane and the adjoining parts of the posterior surfaces of the
tibia and the fibula. This attachment to the interosseous membrane does not
reach as high as the attachments to the bone. The upper end of the muscle is
bifid, the anterior tibial vessels piercing the membrane between these 2 parts.
As it passes distally, it inclines medially under cover of the flexor digitorum
longus and becomes a strong flattened tendon which grooves the back of the
medial malleolus under cover of the flexor retinaculum. Its tendon enters the
sole and is inserted chiefly into the tuberosity of the navicular bone and the
cuneiform bone. Some slips of the tendon also are inserted into other bones of
the foot. The muscle is a plantar-flexor and invertor of the foot.
Vessels and
Nerves. This region contains
2 main arteries and 1 main nerve. The arteries are the posterior tibial and its
largest branch, the peroneal; the nerve is the posterior tibial. The
posterior tibial nerve lies between the 2 arteries, being closely applied
to the lateral side of the posterior tibial artery. All 3 travel distally
behind the fascia covering the posterior tibial muscle, and when this muscle
passes to a medial position, they continue their course on the skeletal plane.
The nerve takes a straight course and crosses the posterior tibial artery to
gain its lateral side. It supplies the 3 deep muscles and the deep part of the
soleus muscle and then ends deep to the flexor retinaculum (laciniate ligament)
by dividing into medial and lateral plantar nerves. The posterior tibial
artery is the larger of the 2 terminal branches of the popliteal artery. It
begins at the upper border of the soleus and ends deep to the flexor
retinaculum by dividing into the medial and the lateral plantar arteries. The
flexor hallucis longus muscle lies laterally, and the flexor digitorum longus
lies medially; the fascia covering the posterior tibial muscle, the shaft of
the lower end of the tibia and the capsule of the ankle joint all lie anteriorly. When the fascia is relaxed by inverting the
foot, the pulsations of the artery can be felt about a finger's breadth from
the medial malleolus. The peroneal artery arises from the posterior
tibial artery before the latter is crossed by the tibial nerve. It descends
first behind the fascia covering the tibialis posterior muscle deep to the
flexor hallucis longus; then it continues downward behind the fibula and the
ankle joint to end on the lateral surface of the calcaneus as the lateral
calcanean artery.
TIBIA The tibia, or shin bone, is the medial and
the larger of the 2 bones of the leg. It presents a proximal end, a shaft and a
distal end. The proximal end is the larger of the two, its transverse
diameter is wider, and it is bent slightly backward. It consists of a tubercle,
lateral and medial condyles, an intercondylar area and eminence, fibular facets
and a groove for the semimembranosus. This massive prismatic upper end is
broader from side to side than from before backward, and it is curved so that
it overhangs the posterior surface of the shaft. Being so greatly expanded, it
provides a good weight-bearing surface for the lower end of the femur. The
tubercle (tuberosity) is seen in front of and below the condyles, about
FIG. The tibia
and the fibula seen from behind. The origins are presented in red; the
insertions, in blue.
FIG. Diagram of
a cross section of the tibia and the fibula, showing the bony borders and
surfaces.
The soleal {popliteal) line appears
as a rough ridge which crosses this border obliquely from the fibular facet to
the medial margin. Extending downward from this line is the vertical line, to
the lateral side of which is found a large foramen for the nutrient artery. The
distal end of the tibia presents 5 surfaces, a medial malleolus and a
fibular notch. The medial surface is subcutaneous and continues below as
the medial malleolus. The anterior surface is rounded and covered with
extensor tendons. The posterior surface also is rounded and is grooved
on the malleolus for the tibialis posterior. The inferior {tarsal) surface is
quadrilateral and wider in front than behind; it is slightly concave from
behind forward and convex from side to side. It articulates with the upper
surface of the talus. The lateral surface is occupied by a triangular
depression known as the fibular notch. The medial malleolus can
be palpated without difficulty. It lies a little anterior to the lateral
malleolus and does not extend as far downward. Its apex gives attachment to the
deltoid ligament of the ankle joint, and its posterior aspect is grooved by the
tendon of the tibialis posterior. Its lateral surface articulates with the
talus. The epiphysis of the lower end is represented by a horizontal line about
a ¼ inch above the broad lower end of the bone. The metaphysis is
separated by the whole thickness of the epiphysis. Diseases of the tibia,
either in the upper or the lower end, are unlikely to affect the joint because
of the epiphyseal and the capsular relationships.
Attachments to the Tibia
:
To the intercondylar area: the
anterior horn of the medial semilunar cartilage and
the
anterior cruciate ligament.
To the intercondylar eminence: the
anterior horn of the lateral semilunar cartilage to the front, and the posterior
horn to the back.
To the intercondylar area: the
posterior horn of the medial cartilage and the posterior cruciate ligament.
To the medial condyle: the
semimembranosus.
To the tibial tubercle: the
ligamentum patellae.
To the shaft: the
tibialis anterior from the lateral condyle and two thirds of the lateral
sulcus. From the upper part of the medial surface, the
sartorius, the gracilis, the semitendinosus and the medial ligament of the
knee.
To the soleal line: the
popliteus and the tibialis posterior from the upper two thirds of the lateral
area of the posterior surface.
From the vertical line: the
fascia covering the tibialis posterior and the flexor digitorum longus from the
upper two thirds of the area medial to the vertical line.
To the anterior and the medial
borders: the fascia of the leg and the superior extensor
retinaculum to the lower part of the anterior border.
To the interosseous border: the
interosseous membrane.
To the fibular notch: the
interosseous tibiofibular ligament and the inferior tibiofibular ligaments to
the lower parts of its anterior and posterior margins. The
anterior ligament of the ankle to the anterior border of the tarsal tibial
surface, and the posterior ligament of the ankle and the transverse
tibiofibular ligament to the posterior border.
To the medial malleolus: the
deltoid ligament, the flexor retinaculum and the inferior extensor retinaculum.
FIBULA The fibula is the lateral of the 2 bones
of the leg; it is slender and is attached above and below to the lateral aspect
of the tibia. It can be divided conveniently into proximal and distal ends and
a shaft. The proximal end consists of a head, a neck and a styloid
process. The head appears as an irregular cuboidal area which has on its
upper surface a triangular facet which articulates with the lateral condyle of
the tibia. Projecting upward from its posterolateral aspect is the blunt-shaped
styloid process (apex), to the top of which the short lateral ligament
of the knee joint is attached. The fibular head can be felt through the skin on
the posterolateral aspect of the knee, below the level of the joint. The
lateral popliteal (common peroneal) nerve can be felt and rolled by the fingers
on the back of this head, although it is separated from it by the uppermost
fibers of the soleus muscle. The neck is that constricted portion just
below the head where the lateral popliteal nerve divides over its lateral side.
The shaft reveals 3 borders, 3 surfaces and a crest. The interosseous
border is ill defined on the medial side of the anterior border; it extends
from the neck to the apex of a rough triangle on the medial side of the distal
end. It provides attachment for the interosseous membrane. The anterior
border is sharp and distinct in its lower half, but it may be masked and
joined with the interosseous border in its upper fourth. The posterior
border is blunt but well defined and extends from the neck to the medial
margin of the back of the lateral malleolus. The lateral (peroneal) surface is
situated between the anterior and the posterior borders; it faces laterally
above but becomes twisted so that below it faces directly backward. The anterior
(extensor) surface is that strip which is situated between the anterior and
the interosseous borders. It is very narrow proximately but is wider distally.
The posterior surface is situated between the posterior and the
interosseous borders and is subdivided into 2 parts by the medial crest. The medial
crest is at times the most prominent ridge on the bone. It begins at the
neck and ends interiorly by continuing into the interosseous border a few
inches above the distal end. This crest is closely related to the peroneal
artery. The distal end of the bone may be considered the lateral
malleolus. It is pyramidal in shape and compressed from side to side. It
presents 4 surfaces, of which the medial reveals a triangular facet for
articulation with the lateral surface of the talus. The lateral surface is
smooth and convex and palpable subcutaneously. It forms the lateral prominence
of the ankle and extends to a slightly lower level than the medial malleolus.
The anterior surface is narrow and not sharply defined from the lateral.
The posterior surface presents a longitudinal groove for the tendons of
the peroneus longus and the brevis. The medial surface reveals a large
articular area for the talus.
Attachments to the Fibula:
To the head: the
capsule of the superior tibiofibular joint. The arcuate ligament of the knee to
the styloid process, the lateral ligament of the knee and the biceps in front
of that process, the muscles and their fasciae which arise from the upper part
of the shaft and also arise from the adjoining part of the head and the fascia
lata.
From the shaft: from
the anterior surface, the extensor digitorum longus, the peroneus tertius and
the extensor hallucis longus; from the posterior surface, the soleus and the
flexor hallucis longus. From the lateral surface, the
peroneus longus and the brevis. From the anterior
border, the anterior intermuscular septum and the superior extensor
retinaculum.
To the lateral malleolus: the
anterior inferior tibiofibular ligament, the anterior talofibular ligament and
the calcaneofibular ligament. The posterior inferior
tibiofibular ligament, the superior peroneal retinaculum, the posterior
talofibular ligament and the transverse tibiofibular ligament to the malleolar
fossa.
The epiphyses of
the fibular appear as bulbous ends at both extremities. The capsules are
attached to the articular margins, and the metaphyses are entirely
extracapsular. The epiphyseal line at the lower end is at the level of the
ankle joint. This anatomic point is important, since a disease of the ankle
joint may spread to the shaft of the fibula and vice versa.
FIG. Surgical
approach to the tibia.
FIG. Surgical
approach to the fibula.
SURGICAL
CONSIDERATIONS
APPROACHES TO
TIBIA AND FIBULA The tibia can be approached along its exposed medial surface.
The saphenous nerve and the great saphenous vein should be avoided. The fibula is
exposed in such a way that the superficial (musculocutaneous) peroneal nerve is
avoided. The proximal and the middle thirds can be approached through an
incision along the line of the posterior intermuscular septum. The upper third
of the shaft can be approached through an incision between the adjoining
borders of the soleus and the peroneus longus muscles. The common peroneal
(external popliteal) nerve must be protected where it winds around the neck of
the fibula. In the middle third, a lateral incision is made through the
interval between the peroneus longus and the flexor hallucis longus muscles.
The distal third of the shaft is exposed just behind the anterior intermuscular
septum, between the peroneus brevis and the tertius muscles.
LEG
AMPUTATION The technic for leg amputation in the middle third utilizes a long
anterior flap and a short posterior flap. The deep fascia is included in these
flaps, and in those patients whose circulation seems to be adequate, an
additional 2 or
FIG. Leg
amputation. In C it should be noted that the fibula is cut at a higher
level than the tibia; the tibia is beveled.
FRACTURES OF
SHAFT OF TIBIA AND FIBULA The shafts of both bones of the leg are fractured
more commonly in young adults and children. If the injury is caused by indirect
violence, the tibia usually breaks at its weakest point, which is the junction
of the middle and the lower thirds; the fibula usually fractures at a higher
level. If the cause is direct violence, the bones are broken at the same level,
the fractures being transverse and at the site of injury. The lower fragment is
pulled upward by the action of the calf muscles; the weight of the foot
produces outward rotation. In the treatment of these fractures, reduction may
be difficult. The knee always should be flexed, to relax the calf muscles. To
check on proper alignment, the inner margin of the great toe, the internal
malleolus and the inner margin of the patella should all be in the same line.
ANKLE
The ankle consists of the ankle joint (the tibia
and the fibula proximally, and the talus distally) and those (structures which
surround it. The 2 malleoli can be felt distinctly, the lateral being less
prominent, descending lower and lying farther back
than
the medial. The tip of the lateral malleolus is about ½ inch below and
behind the tip of its corresponding bony prominence. Anterior to the lateral
malleolus and lateral to the tendon of the peroneus tertius is a shallow
depression which indicates the level of the ankle joint. A similar depression
lies between the medial malleolus and the tibialis anterior tendon. At these
two points the ankle joint is very superficial, and, when fluid is present,
these areas become filled and form soft projections. If the foot is forcibly
plantarflexed, the talus (astragalus) glides forward out of its socket and
produces a prominence which is most apparent in front of the lateral malleolus.
The medial or internal malleolus is large, flat and prominent. The ankle joint
lies approximately ½ inch above the tip of the internal malleolus. The
tendo calcaneus (achillis) stands out prominently at the back of the ankle;
between it and the malleoli are 2 hollowed grooves. Over the front of the
ankle, the tendons of the extensor muscles stand out in bold relief, especially
when the joint is flexed. From within outward, they are: the tendon of the
anterior tibial muscle, the extensor hallucis longus, the extensor digitorum
longus and the peroneus tertius. Above and behind the medial malleolus, the
tendons of the posterior tibial and the flexor digitorum muscles are noted; the
former lies closer to the bone. Behind the lateral malleolus, the long and the
short peroneal tendons can be felt lying close to the edge of the fibula, the
tendon of the smaller muscle being the closer to it. The interval between the
medial malleolus and the calcaneus is crossed by the laciniate (internal
annular) ligament, which also forms an osteo-aponeurotic canal in which are
found the tendons of the flexor digitorum longus, the flexor hallucis longus
and the posterior tibial muscles. The tendon of the tibialis posterior muscle
lies immediately behind the back of the medial
FIG. The structures surrounding
the right ankle: (A) seen from behind; (B) the lateral structures; (C) the
medial structures.
FIG. The
relations around the right ankle joint. The deep fascia and the
ligaments are shown in blue.
malleolus
and is succeeded by the tendons of the flexor digitorum longus and the flexor
hallucis longus. The posterior tibial vessels and nerves lie between the last
two named tendons. The tendons lie in close relation to the ankle joint, but
the calcaneal tendon is separated from it by a considerable interval. A fairly
wide space which is filled with fatty areolar tissue also exists between the
flexor hallucis longus tendon and the posterior tibial vessels, so that there
is little chance of damage when operating on this tendon. The skin about
the ankle is thin and loosely attached to the subjacent parts. Owing to its
proximity to the underlying malleoli, it may be damaged by the pressure of a
cast or a bed rest. The subcutaneous tissue varies both in quantity and
character. Over the front of the ankle it is lax and free from fat; therefore,
if edema is present, the skin will pit on pressure.
DEEP FASCIA The deep fascia is strong and is
directly continuous with the fascia which invests the leg and the foot.
FIG. The 5
binding bands around the ankle.
It forms 5 definite bands (in front of and at each
side of the ankle) which maintain the tendons in contact with the bones, and it
assists in forming osteo-aponeurotic tunnels through which the tendons and
their synovial sheaths pass.
The 5 binding bands are:
the 2 anterior bands, the transverse crural and the cruciate ligaments; 1
medial band, the laciniate ligament; 2 lateral bands, the peroneal
retinacula. The anterior thickening of the deep fascia has 2 divisions:
an upper and a lower. The upper division, or the transverse crural ligament,
stretches between the anterior borders of the tibia and the fibula
immediately above the 
FIG. The 3 tendon sheaths of the
anterior aspect of the ankle.
ankle
joint. Beneath this ligament are the structures which pass from the front of
the leg to the dorsum of the foot. With the exception of the tibialis anterior,
which lies separately, they lie in one compartment. The structures from medial
to lateral are: the anterior tibial muscle, the extensor hallucis longus, the
anterior tibial vessels, the deep peroneal nerve, the extensor digitorum longus
and the peroneus tertius. The structures which pass over the superficial
surface of this ligament are: the long saphenous vein, the saphenous nerve and
the superficial peroneal nerve. The cruciate ligament is the lower division
of the anterior thickening of deep fascia; it has been referred to as the
inferior extensor retinaculum. It is the more important of the two. Its shape
resembles the letter "Y," the stem of the letter being the lateral
part of the ligament. The Y is placed on its side and lies across the dorsum of
the foot close to the ankle joint. It is firmly attached to the anterior part
of the upper surface of the calcaneum. The upper limb of the Y attaches to the
medial malleolus; the lower part fuses with the deep fascia along the medial
margin of the foot, and with the plantar fascia. The structures which pass
beneath this ligament are identical with those passing under the transverse
ligament. It splits to form 2 compartments. The medial of these is occupied by
the tendon of the extensor hallucis longus; the lateral compartment, by the
peroneus tertius and the extensor digitorum longus. Each compartment is lined
with a synovial sheath. The vessels and the nerves pass deeply to the ligament.
The ligament usually does not form a compartment for the tibialis anterior
tendon, because the tendon runs either above or below the ligament. The
laciniate ligament (internal lateral) bridges the hollow between the medial
malleolus and the calcaneus, to both of which it is attached. It has 4 borders
and 2 surfaces. Of its borders, the upper is continuous with 2 layers of fascia
– the deep fascia of the leg and the strong fascia which extends between the
superficial and the deep muscles of the calf. The lower border is continuous
with the medial part of the plantar aponeurosis. The lateral border is attached
to the tuberosity of the calcaneus; and the medial, to the medial malleolus. Of
its surfaces, the superficial is related to the medial calcaneal vessels and
nerves, which first pierce it and then cross it; the deep surface is related to
the tendons, the vessels and the nerves passing in back of the leg to the sole
of the foot. These lie in a compartment, in the following order from before
backward: the posterior tibial tendon, the flexor digitorum longus, the
posterior tibial artery with its companion veins, the posterior tibial nerve
and the flexor hallucis longus. Each tendon is supplied with a synovial sheath
of its own. Under the lower part of this ligament the artery and the nerve both
divide into medial and lateral plantar branches.
The peroneal
retinacula are 2 lateral thickened parts of the deep fascia;
they also have been referred to as the external annular ligaments. They bridge
the groove between the lateral malleolus and the calcaneus. The superior
peroneal retinaculum extends from the calcaneus to the lateral malleolus
and binds the 2 peronei, the longus and the brevis, to the back of the lateral
malleolus. The brevis lies closer to the bone. The inferior peroneal
retinaculum is attached to the outer surfaces of the calcaneus. It is
divided into 2 compartments by a septum which is attached to the peroneal
tubercle. The superior retinaculum forms a common compartment for the peronei,
unlike the inferior retinaculum, which forms 2 compartments.
TENDON
SHEATHS The tendon sheaths around the ankle joint are mucous sheaths which are
placed anteriorly, medially, laterally and posteriorly. The anterior sheaths
appear as 3 separate structures. They are: the sheath of the tibialis
anterior, which extends from the upper border of the transverse ligament to
just below the ankle joint; the sheaths of the extensor hallucis longus and of
the extensor digitorum longus, which extend from the malleoli to the base of
the metatarsal bones. The medial mucous sheaths are also
FIG. The
arteries around the ankle, as seen from behind.
VESSELS The arteries
around the ankle are mainly
ANKLE JOINT (TALOCRURAL) The ankle joint is a
synovial joint of the hinge variety which unites the foot to the leg. Its great
strength and stability are ensured by surrounding powerful ligaments and
tendons, as well as by a close interlocking of its articulating surfaces.
Because of its hinge action, the to-and-fro movements of walking are possible.
When one walks, the triceps sural (both heads of the gastrocnemius and the
soleus) raises the heel from the ground and produces plantar flexion of the
ankle joint. The 4 anterior crural muscles cause the foot to clear the ground,
and thus produce dorsiflexion of this joint. The malleoli grasp the sides of
the talus, the latter transmitting the weight of the body to the tibia. The sharp
tip of the lateral (fibular) malleolus can be felt a little less than
BONES The bones that enter into the formation of
the ankle joint are the talus and the distal ends of the tibia and the fibula. The
talus articulates with the bones of the leg by 3 of its surfaces: the
upper, the medial and the lateral. The bones form a deep socket which receives
the upper part of the talus. Tibia and Fibula. The roof of the joint is
formed entirely by the tibia. As the 2 malleoli project downward, they grasp
the talus firmly at each side, thus permitting only a slight degree of lateral
or medial movement. The bones just mentioned are so intimately related with the
tarsal bones and joints in the mechanics and the alignment of the ankle joint
that it is impossible to isolate the ankle joint from the rest of the foot in
either clinical or anatomic discussions.
LIGAMENTS. Capsular Ligament. The bones that form the ankle joint are held together by a
capsular ligament which is subdivided into anterior, posterior, lateral and
medial ligaments. The capsule is loose in front and behind and tight at the
sides. Proximally, it is attached to the margins of the articular surfaces of
the tibial and the fibular epiphyses and distally to the margins of the
superior articular surface of the talus except at the anterior aspect of the
joint, where it extends forward to the neck of the bone. The medial part of
this capsule is greatly thickened and is named the deltoid ligament. It
is triangular in shape, with its apex attached above to the tip of the medial
malleolus. Its base has a more extensive attachment, extending from the
tubercle of the navicular, the plantar calcaneonavicular (spring) ligament, the
neck of the talus and the sustentaculum tali to the body of the talus. Its
medial surface is crossed by the tendons of the tibialis posterior and the
flexor digitorum longus. If the foot is everted to an extreme degree, the deltoid
ligament usually tears away from the medial malleolus
FIG. The
ligaments around the ankle joint.
rather
than rupturing itself. It braces the spring ligament and helps to support the
head of the talus and to preserve the arch of the foot.
The lateral ligament is
weaker and less complete. Most authors divide it into 3 parts. 1. The
calcaneofibular ligament extends downward and backward from in front of the
apex of the lateral malleolus to the lateral surface of the calcaneus. These
fibers are separated from the other fibers of the lateral ligament by some
fatty and areolar tissues. The ligament is crossed by the peronei. 2. The
anterior talofibular ligament passes horizontally forward and inward from
the anterior aspect of the lateral malleolus to the lateral side of the neck of
the talus. 3. The posterior talofibular ligament extends inward behind
the joint, from the inner surface of the lateral malleolus to the posterior
process of the talus. It is the strongest of the 3 bands and binds the fibula to
the talus in a rigid manner. The anterior ligament of the ankle joint is
a thin wide membrane which is composed chiefly of transverse fibers. It extends
from the anterior margin of the distal surface of the tibia to the dorsal
surface of the neck of the talus. A cut across the foot immediately in front of
the tibia will open the ankle joint at this point. The posterior ligament is
the weakest of all the ankle ligaments. It is thin, sometimes defective and
difficult to define. It extends from the posterior border of the distal end of
the tibia to the posterior surface of the talus. The tendon of the flexor
hallucis longus acts as a strong posterior support for the joint.
SYNOVIAL MEMBRANE The synovial membrane lines the
capsular ligament and covers the intracapsular portion of the neck of the
talus. It passes up between the tibia and the fibula for about ¼ inch
and extends well forward onto the neck of the talus. A puncture wound or
superficial incision made in front of the joint may enter the joint cavity. The
membrane is lax in front and behind where it is covered by the anterior and the
posterior ligaments, at which points the capsular ligament is thin and loose.
It is continuous with the synovial membrane of the distal tibiofibular joint. A
joint effusion bulges the synovial membrane and the weak capsule anteriorly and
posteriorly.
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VESSELS AND NERVES The nerves to the ankle joint
are derived from the anterior and the posterior tibial nerves. Relations:
Anterior. From the medial to the lateral side lie the tibialis anterior,
the extensor hallucis longus, the anterior tibial vessels, the anterior tibial
nerves, the extensor digitorum longus and the peroneus
tertius.
The perforating branch of the peroneal vessels is found on the lateral
malleolus. The inferior extensor retinaculum crosses the joint obliquely. The
superficial structures which are found in this region are the branches of the
musculocutaneous nerve, the superficial vessels, the long saphenous vein and
the saphenous nerve on the medial malleolus.
Posterior. The
tendo calcaneus is separated from the posterior ligament by an interval of
fatty areolar tissue which contains small vessels. Between the joint and the
tendon are found the flexor hallucis longus, the posterior tibial nerves and
vessels, and the flexor digitorum longus, the latter structures being named in
a lateromedial order. The vessels and the nerves are more superficial than the
2 flexors and overlap them. All of these structures are maintained in position
by the flexor retinaculum.
Medial. The
tibialis posterior lies on the deltoid ligament above the sustentaculum tali,
and the flexor digitorum longus lies on the attachment of that ligament to the
sustentaculum. The flexor retinaculum overlies the tendon.
FIG. Cross sections through the
ankle and the foot: (A) section taken through the malleoli; (B) section taken
through the calcaneus and the talus.
Lateral. The peroneus
brevis lies on the posterior talofibular ligament and separates the peroneus
longus from it. Its tendons are held down by a retinaculum of deep fascia; they
have a common synovial sheath. The termination of the peroneal artery
anastomoses with its perforating branch on this side of the joint. More
superficially are the short saphenous vein and the sural nerve.
MOVEMENTS The movements of the ankle joints
involve the joints of the foot as well. Inversion and eversion of the foot are
effected by plantar flexion (true flexion) and dorsiflexion (extension).
Plantar flexion and dorsiflexion are effected mainly
at the ankle joint between the talus, the tibia and the fibula. Dorsiflexion is
limited by the lengthening of the calf muscles; if the knee is flexed, the
range of movement is greater. Plantar flexion is produced by the gastrocnemius,
the soleus and the flexor hallucis longus; it also is produced to a minor
degree by the tibialis posterior, the peroneus longus and the plantaris
muscles. When the foot is moved so that the sole faces medially, the movement
is described as inversion; the contrary movement is eversion. Inversion of the
foot is brought about by the action of the tibialis anterior and the tibialis
posterior; eversion is accomplished by the peronei longus, the brevis and the
tertius. A greater range of inversion may be produced when the ankle joint is
plantar flexed; this is due apparently to an increased range of metatarsal
movement. The 5 tendons which pass behind the ankle are situated too close to
the axis of the joint to act on it; therefore, if the tendo calcaneus is cut,
the power to plantar flex is lost.
SURGICAL
CONSIDERATIONS
SYME'S
AMPUTATION THROUGH THE ANKLE JOINT This is a disarticulation
with removal of both malleoli and the articular surface of the tibia. The
incision passes under the heel, from the tip of the lateral malleolus to a
corresponding point on the medial malleolus. The distal ends of the tibia and
the fibula are exposed, and these bones are sectioned about
In the Pirogoff
amputation, the posterior portion of the calcaneus is sawed off and ap proximated to the sawed end of the tibia and the fibula.
Therefore, it is a modified Syme's amputation, the
only difference being that part of the calcaneus is retained and brought into
contact with the divided lower ends of the tibia and the fibula.
FIG. Amputation through the ankle
joint (Syme).
DISLOCATIONS
OF THE ANKLE JOINT Dislocations of the ankle joint (between the talus and the
tibia and the fibula) are classified according to the direction in which the
foot passes: namely, backward, forward, medial, lateral or upward.
Lateral and
medial displacements occur in association with Pott's
fracture or fractures of the malleoli.
In forward
(anterior) dislocation, the ligaments or malleoli are torn,
the heel is shortened and the distance from the malleoli to the heel is
diminished; the distance from the malleoli to the toes, however, is increased.
The foot appears to be lengthened, the normal hollows at the sides of the tendo
achillis are obliterated, and the talus may be felt in front of the tibia. The
malleoli appear to lie nearer the sole.
Backward
dislocation is the most frequent type; this may be associated
with a Pott's fracture. It results from extreme plantar flexion of the foot
which tears the ligaments. Involvement of the malleoli and the posterior articular
edge of the tibia is usually present. The foot appears to be shortened, and the
heel is prominent. The malleoli appear somewhat anteriorly. The distance from
the malleoli to the heel is increased, while that from the malleoli to the toe
is diminished. Reduction is easy if the knee is bent to relax the tendo
achillis and if proper traction and counter traction are applied.
FOOT
The foot, which is triangular in outline, extends
from the point of the heel to the root of the toes. It is divided into the
tarsus (posterior half) and the metatarsus (anterior half). The landmarks which
are visible over the lateral aspect are thin in contrast with the more bulky
medial markings.
LATERAL, MEDIAL AND DORSAL ASPECTS The lateral
margin of the foot rests in contact with the ground over its entire extent.
Near the middle of this border, the tuberosity of the base of the 5th
metatarsal bone affords a landmark for the tarsometatarsal joint (Lisfranc). If
a line is constructed between the tuberosity of the base of the 5th metatarsal
and the tip of the lateral malleolus, and a point just anterior to the middle
of this line is marked, the cuboid midtarsal joint (Chopart) is located.
The medial aspect of
the foot is arched, in contrast with the flat appearance of the lateral border.
The medial border rests on the ground only at the heel and the ball of the
great toe. The sustentaculum tali is located about
The dorsum of
the foot reveals a very thin skin, which is much less sensitive than that on
the plantar surface. The subcutaneous tissue over the dorsum is very loose, so
that edema becomes quite prominent in this region. The veins are arranged in an
arch, the outline of which is apparent when one is in the erect posture. The
large and the small saphenous veins arise from the marginal veins of this arch.
The tendons in front of the ankle can be traced over this surface to their
insertions. The tendon of the extensor hallucis longus passes forward to the
great toe, and the tendons of the extensor digitorum longus pass to the 4
lateral toes. A fleshy muscular mass, the extensor digitorum brevis muscle, can
be felt on the posterolateral aspect of the dorsum. The tendon of the peroneus
brevis muscle passes forward under the lateral malleolus to its insertion into
the tuberosity of the 5th metatarsal. The dorsalis pedis artery, a continuation
of the anterior tibial artery, may be indicated on the surface by a line drawn
midway between the 2 malleoli to the posterior extremity of the first
interosseous space. To the lateral side of this vessel is the anterior tibial
nerve.
SOLE OF THE FOOT (PLANTAR SURFACE)
The skin is thicker on
the sole of the foot than it is over the dorsum. It is particularly thick over
those points which bear weight (heel, ball of the big toe and lateral margins
of the sole). Like the palm of the hand, it is highly sensitive and contains
numerous sweat glands.
The cutaneous nerves are
arranged in the following way: the medial plantar nerve supplies the 3
½ digits on the big-toe side of the foot, as the median nerve supplies
the 3 ½ digits on the thumb of the hand; the lateral plantar nerve, which
corresponds to the ulnar nerve of the hand, supplies the remaining 1 ½ digits. The medial calcaneal branches of the
posterior tibial nerve supply the skin under the heel.
The superficial fascia becomes
thick and tough along the lateral border, on the ball of the foot and at the
heel. Traversing it are
small
but tough fibrous bands which subdivide the fatty tissue into small lobules;
these bands also connect the skin with the deep fascia.
DEEP PLANTAR APONEUROSIS (DEEP FASCIA) The deep
(plantar) fascia arrangement resembles that of the hand. It lies superficial to
the vessels, the nerves, the muscles and the tendons, and consists of 3
portions: relatively thin medial and lateral parts and a very dense and strong
intermediate part. This thickened strong central part is known as the plantar
aponeurosis. It forms a dense fibrous sheet which is attached posteriorly to
the calcaneus and widens anteriorly to divide into five slips, one for each
toe. (The palmar aponeurosis of the hand divides into 4 slips, one for each
finger, but none for the thumb.)
FIG. The foot
seen in cross-sectional views.
Therefore, the great toe has a different
relationship to this fascia than that of the thumb to the deep fascia of the
palm; hence its mobility is diminished as compared with that of the thumb. The
slips to the toes are connected to the fibrous flexor sheaths and to the sides
of the metatarsophalangeal joints.
Fibrous
Flexor Sheaths. On each toe
the deep fascia is thickened to form curved plates called the fibrous flexor
sheaths; these hold the flexor tendons against the phalanges. They are strong
and dense opposite the phalanges but are thin and weak opposite the joints, so
that movements are not hindered. These sheaths are attached to the margins of
the phalanges and to the plantar ligaments and form with them a tunnel which is
occupied by the long and the short flexor tendons. This tunnel is lined with
the synovial sheath that envelops the tendons. The medial division of the deep
fascia covers the abductor hallucis muscle; the lateral part of the fascia
extends between calcaneus and the tuberosity of the 5th metatarsal.
FIG. The cutaneous nerve supply of
the foot: (A) the dorsum of the foot; (B) the plantar surface of the foot.
FIG. The plantar
fascia.
FIG. The 4
layers of muscles and tendons of the sole of the foot.
MUSCLES AND TENDONS The
muscles and the tendons of the sole of the foot are arranged in 4 layers which
are separated by fascial partitions; in these the plantar nerves and vessels
run. Only the muscles of the first layer cover the whole extent of the sole.
The muscles of the second layer are all connected to the flexor digitorum
longus tendon and form an X-shaped figure, so that on each border of the foot
the first and the third layers come into contact with each other.
The First
Layer of Muscles. This consists
of the abductor hallucis, the flexor digitorum brevis and the abductor digiti
quinti. The flexor digitorum brevis divides into 4 tendons which pass to
the 4 lateral toes and become inserted into the middle phalanges. The
abductor hallucis is inserted into the medial side of the base of the
proximal phalanx of the great toe, and the abductor digiti minimi is
inserted into the lateral side of the base of the proximal phalanx of the
little toe. The names of these muscles indicate their actions. The lateral
plantar nerve supplies the abductor digiti minimi, and the other 2 muscles are
supplied by the medial plantar nerve.
The second layer of
muscles consists of the flexor digitorum longus, the flexor accessorius
(quadratus plantae), the lumbricales and the flexor hallucis longus. The
tendon of the flexor digitorum longus passes forward and laterally from the
medial flexor retinaculum. At first it lies on the medial side of the
sustentaculum tali, and then it crosses superficial to the flexor hallucis
longus tendon, which separates it from the plantar calcaneonavicular ligament.
This tendon constitutes the central structure in this layer of muscles. It
should be recalled that this tendon has crossed superficially to the tendon of
the tibialis posterior at the back of the medial malleolus; it now appears from
under cover of the abductor hallucis and crosses superficially to the tendon of
the flexor hallucis longus. Therefore, it appears superficial at 2 points –
once where it crosses the tibialis posterior and again where it crosses the
flexor hallucis longus. As it receives the insertion of the flexor digitorum accessorius,
it divides into 4 tendons for the lateral 4 toes. These tendons resemble those
of the flexor digitorum profundus in the hand, since they pass through rings
made by the splitting of the fibers of the short flexor tendon and then pass on
to become inserted into the distal phalanges. The flexor digitorum
accessorius {quadratus plantae) muscle arises by 2 heads – one from each
side of the calcaneus. The medial head, which is wide and fleshy, arises from
the medial surface of the calcaneus. The lateral head, which is narrow and
tendinous, arises from the lateral margin of the plantar surface of the bone.
It inserts into the tendon of the flexor digitorum longus, in the region of the
middle of the sole, and acts as a flexor of the toes. It is supplied by the
lateral plantar nerve. The lumbricales are
The third layer of muscles consists
of the flexor hallucis brevis, the adductor hallucis (oblique and transverse
heads) and the flexor digiti quinti brevis. The muscles of this layer are
limited to the anterior part of the foot. A plan of origin of these muscles may
be remembered if it is recalled that the base of each of the 5 metatarsal bones
gives origin to a muscle; therefore, the 1st gives rise to the flexor hallucis
brevis; the 2nd, the 3rd and the 4th to the adductor hallucis (oblique head)
and the 5th to the flexor digiti quinti. The flexor hallucis brevis covers
the plantar aspect of the first metatarsal; its belly divides into 2 heads. The
medial head is inserted, in common with the abductor hallucis, into the medial
side of the base of the proximal phalanx of the hallux, and the lateral head is
inserted into the lateral side of the same bone in common with the adductor. A
sesamoid bone usually is developed in each tendon of insertion; it flexes the
first metatarsophalangeal joint. The nerve supply to this muscle derived from the
medial plantar nerve. The adductor hallucis muscle resembles the
adductor pollicis in that it has oblique and transverse heads. It arises from
the 2nd, the 3rd and the 4th metatarsal bones and is inserted in common with
the lateral head of the flexor hallucis brevis. The transverse head is a small
muscle bundle which is located under the heads of the metatarsal bones. It
arises from the plantar ligaments of the 3rd, the 4th and the 5th
metatarsophalangeal joints and is inserted in common with the preceding muscle.
The nerve supply is derived from the lateral plantar nerve. The flexor
digiti quinti brevis is the short flexor of the little toe. It is a single
fleshy muscle slip which arises from the base of the 5th metatarsal bone and
the peroneus longus tendon. It inserts into the lateral side of the base of the
proximal phalanx of the little toe and flexes the little toe at the
metatarsophalangeal joint. It is supplied by the lateral plantar nerve.
The fourth layer of muscles consists
of the interossei (plantar and dorsal), the tendon of the peroneus longus and
the tendon of the tibialis posterior. The interossei are 7 interosseous
muscles – 3 plantar and 4 dorsal. As in the hand, the dorsal are abductors, and
the plantar are adductors; but the line of action passes through the 2nd digit
and not the 3rd, as in the hand. They lie between the metatarsal bones and
arise from them. They abduct and adduct the lateral 4 toes to and from the
middle line of the 2nd toe and also aid in flexion of the
metatarsophalangeal joints. The 3 plantar interossei arise from the
plantar and the medial surfaces of the lateral 3 metatarsal bones, and each is
inserted onto the medial side of the corresponding toe. They are so placed that
they adduct the lateral 3 toes toward the 2nd toe. The 4 dorsal interossei
arise by 2 heads from the dorsal parts of the sides of the metatarsal bones
between which they lie. They are inserted in the following manner: the 1st on
the medial side of the 2nd toe, the 2nd on the lateral side of the same toe,
the 3rd on the lateral side of the 3rd toe, and the 4th on the lateral side of
the 4th toe. By this arrangement, they abduct the 2nd, the 3rd and the 4th toes
from the midline of the 2nd toe. The peroneus longus tendon runs
obliquely and medially across the sole of the foot, in the groove on the
plantar surface of the cuboid bone, to become inserted into the base of the 1st
metatarsal bone and the adjoining part of the medial cuneiform. It is held in
place by a strong fibrous sheath which is derived from the long plantar
ligament. This tendon is situated below the transverse arch of the foot and, by
taking the strain off the interosseous ligaments, it aids in maintaining the
arch. Together with the tendon of the tibialis anterior, it forms a tendon sling
for the anterior part of the tarsus. The common synovial sheath which envelops
the peronei longus and brevis, behind the malleolus, commonly is continued with
the synovial sheath of the longus into the sole of the foot. Therefore, any
injury to either tendon in the region of the ankle may find a pathway into the
sole by means of the sheath. The peroneus longus is an evertor of the foot. It
is supplied by the superficial peroneal (musculocutaneous) nerve. After the tibialis
posterior tendon enters the sole, it divides into 2 parts. The medial is
the larger part and inserts into the tuberosity of the navicular bone; the
lateral part divides into slips which spread out from it to every bone of the
tarsus except the talus and also to the bases of the 2nd, the 3rd and the 4th
metatarsal bones. The tendon lies on the plantar surface of the so-called
spring ligament (calcaneonavicular). This muscle is an evertor and flexor of
the foot. Because of its close association with the spring ligament, it is of
some importance in supporting the arch. It is supplied by the posterior tibial
nerve.
ARTERIES The posterior
tibial artery divides into the lateral and the medial plantar arteries at the
distal border of the laciniate ligament. The lateral plantar artery is
larger than the medial and is considered the continuation of the posterior
tibial. It appears from under cover of the abductor hallucis muscle and, with
its companion nerve, runs forward and laterally between the 1st and the 2nd
layers of muscles (flexor digitorum brevis and flexor accessorius). It then
dips deeper as it continues medially between the 3rd and the 4th layers
(adductor hallucis obliquus and the interossei). At the back end of the first
intermetatarsal space it anastomoses with the profunda branch of the dorsalis
pedis artery (anterior tibial), thus forming a deep plantar arterial arch. In
the first part of its course the artery gives off calcaneal branches to the
skin of the heel and muscular and cutaneous branches to the skin of the sole of
the foot.
FIG. The vessels and the nerves of
the sole of the foot: (A) superficial dissection; (B) deep dissection.
The plantar arch gives
off perforating branches, which pass upward through the lateral 3
intermetatarsal spaces, and plantar digital arteries
to the lateral 3 clefts and the lateral side of the little toe. The arteria
magna hallucis supplies the cleft between the great toe and the 2nd toe, and
sends a branch to the medial
side of the former; it is derived from the dorsalis pedis at its point of union
with the plantar arch. The medial plantar artery varies in size but
usually is small. It is accompanied by its venae comitantes and passes along
the medial side of the medial plantar nerve. It ends by joining the digital
branch which the first metatarsal artery sends to the medial side of the big
toe.
NERVES The
medial plantar nerve arises from the posterior tibial nerve; it corresponds
to the median nerve of the hand. It passes forward into the sole of the foot,
under cover of the abductor hallucis muscle, accompanied by the medial plantar
vessels, which are on its medial side. Reaching the lateral border of the
abductor hallucis muscle, the nerve runs forward in the interval between that muscle
and the flexor digitorum brevis.
FIG. The bones of the foot and the
toes: (A) seen from below; (B) seen from above.The muscular origins are shown
in red; the insertions, in blue.
It supplies sensory branches to the inner side of
the sole of the foot, to the plantar aspect of the 3 ½ inner toes and to
the corresponding dorsal surfaces of the last 1 ½ to 2 phalanges. It
supplies the motor branches to 4 muscles also: the abductor hallucis, the
flexor digitorum brevis, the flexor hallucis brevis and the first lumbricalis. The
lateral plantar nerve is the smaller of the 2 terminal branches of the
posterior tibial nerve; it corresponds to the ulnar nerve of the hand. It
reaches the outer side of the foot with its accompanying artery by passing
between the flexor digitorum brevis and the quadratus plantar (between layers 1
and 2). It then divides into superficial and deep branches, which supply the
outer 1 ½ toes and all the remaining small muscles of the foot, namely,
the 3 lumbricales, all the interossei, the abductor minimi digiti, the adductor
transversus and the obliques. It should be noted that the lateral and the
medial plantar vessels and nerves, plus 3 tendons, enter the sole of the foot
on its medial side by passing deep to the abductor hallucis muscle; therefore,
this muscle is an important landmark. It must be reflected, and the plantar
vessels displaced before the flexor hallucis longus tendon can be seen where it
lies in the groove between the 2 tubercles of the talus and winds under the
sustentaculum tali.
BONES The tarsus consists of 7 tarsal bones which
may be divided conveniently into a posterior row (talus and calcaneus), a
middle row (navicular) and an anterior row (3 cuneiform bones and the cuboid).
The talus (astragalus, ankle bone) is
discussed also in the region of the ankle joint. It rests on the anterior two
thirds of the calcaneus and has a body, a neck and a head. It lies below the
tibia, sits on the upper surface of the calcaneus and is gripped by the 2
malleoli. The head of the bone is anterior and articulates with the navicular;
below, it rests on the plantar calcaneonavicular (spring) ligament and the
calcaneus. If the foot is inverted (so that the sole faces medially) the head
of the talus is felt as a rounded prominence about
FIG. Side views of the bones of
the right foot: (A) lateral view; (B) medial view.
The calcaneus (os calcis) is
the heel bone. It has a long, arched, anterior two thirds which supports the
talus; the posterior one third forms the prominence of the heel, which rests on
the ground. The anterior surface articulates with the cuboid, and the posterior
third of the upper surface is saddle-shaped. The lateral surface is almost
entirely subcutaneous; it is felt easily below the lateral malleolus as a wide
surface that extends forward about
The navicular bone (scaphoid) is
on the medial side of the foot. It articulates with the head of the talus
posteriorly and with the 3 cuneiforms anteriorly. On its medial side is its
tuberosity, which is useful as a landmark. This tuberosity forms a prominence
which is felt easily about
The 3 cuneiform bones are
termed the first (medial), the second (intermediate) and the third (lateral).
They articulate with the navicular posteriorly and with the first 3 metatarsals
anteriorly. They are wedge-shaped, are placed side by side and articulate with
each other. The lateral cuneiform articulates with the cuboid and the 4th
metatarsal, while the intermediate and the medial cuneiforms grip the base of
the 2nd metatarsal between them. Since the 2nd cuneiform is shorter than the
other two, the base of the 2nd metatarsal articulates on its medial and lateral
sides with the 1st and the 3rd cuneiforms, respectively.
The cuboid lies
on the lateral side of the foot and articulates posteriorly with the calcaneus
and anteriorly with the 4th and the 5th metatarsals. Its medial surface
articulates with the 3rd cuneiform and the navicular, and its plantar surface
presents an oblique groove which lodges the tendon of the peroneus longus.
Webster and Roberts have stressed the importance of tarsal anomalies as the most
common cause of peroneal spastic flat foot. Particularly stressed is the
anomaly that consists of a calcaneonavicular bar or a talocalcaneal ridge.
Therefore, these anomalies become of practical importance.
The metatarsus is
composed of 5 metatarsal bones, which are numbered 1 to 5 from medial to
lateral. Each bone has a head or distal end, a body or midportion and a base or
proximal end. The bases of the 1st, the 2nd and the 3rd metatarsals articulate
with the 3 cuneiforms, and the bases of the 4th and the 5th with the cuboid.
These bases also articulate with each other; the heads articulate with the
proximal phalanges. The bodies present a triangular shape on section and are
concave in their long axes on the plantar surfaces. The 1st metatarsal is the
shortest and the stoutest, and in the majority of people its head extends as
far forward as that of the 2nd metatarsal. The metatarsal bones can be felt
individually through the anterior part of the tarsus under the extensor tendons.
The base of the 5th metatarsal lies proximal to the main metatarsal joint line
and forms a prominent landmark on the outer margin of the foot.
The toes are numbered
from medial to lateral, but the 1st toe is called the hallux, and the little
toe, the digitus minimus. The bones of the toes are the phalanges. The
big toe has 2 phalanges, but all of the others have 3: a proximal, a middle and a distal phalanx. Each proximal phalanx
articulates with the head of a metatarsal bone to form the metatarsophalangeal
joint. The middle phalanx articulates with the other two to form the interphalangeal
joints. The proximal end of each phalanx is called its base, and its distal
end is its head. The accessory bones of the foot are of practical
importance, since they may be mistaken on x-ray films for fractures. Although
similar bones occur in the hand, they are so seldom seen on the x-ray film that
they cannot compare in importance with those of the foot. Accessory bones have
been divided into2 classes: (1) the sesamoids, which are regular constituents
of the skeleton, and (2) the true accessory bones, which are small occasional
ossicles that occur in definite sites. In the vast majority of cases they are
bilateral; hence the importance of examining both feet by x-ray. They occur in
about 25 per cent of human feet (Pfitzner). McGregor lists the following 20
accessory bones of the feet:
1. Os tibiale externum
2. Os trigonum (accessory astragalus)
3. Os vesalianum tarsi
4. Secondary os calcis
5. Secondary cuboid
6. Astragaloscaphoid bone of Pirie
7. Intermetatarseum
8. Os intercuneiforme
9. Os paracuneiforme of Cameron and Carlier
10. Os uncinatum
11. Astragalus secundarius
12. Os subtibiale
13. Os sustentaculum proprium
14. Peroneal process of the os calcis
15. Sesanum peroneum
16. Sesamoid of the flexor hallucis brevis
17. Trochlear process of the head of the
astragalus
18. Process from the middle of the upper surface
of the astragalus
19. Spurs of the os calcis
20. Spurs of the phalanges
FIG. The accessory bones of the
foot.
The phalangeal spurs
are found on any of the distal phalanges, especially those of the great toe.
They may grow from either side of the base of the phalanx and rarely, if ever,
cause symptoms.
JOINTS AND LIGAMENTS Six tarsal joints will be discussed.
1. The talocalcaneal joint is situated
between the large facet on the lower surface of the talus and the corresponding
facet on the middle of the upper surface of the calcaneus. It possesses a
capsular ligament which is attached to the margins of the articular areas of
the 2 bones. Anteriorly, its capsule blends with the interosseous ligament,
which firmly binds the 2 bones together. This ligament is attached to the
inferior surface of the neck of the talus above and to the upper surface of the
calcaneal joint. The capsular ligament, which is attached to the bones near its
margins of the articular facet, is divided into anterior, posterior, lateral
and medial talocalcaneal ligaments. They are composed of short fibers, except
the anterior, which is a continuation of the interosseous talocalcaneal
ligament.
2. The talocalcaneonavicular joint is
considered the most important of the tarsal joints. It is situated between the
rounded head of the talus and a socket formed for it by the posterior surface of
the navicular, the upper surface of the spring ligament and the sustentaculum
tali. The medial end of the ligamentum bifurcatum completes the lateral side of
the socket; this ligament extends between the anterior part of the superior
surface of the calcaneus and the lateral side of the navicular. This 3-boned
joint conforms to a ball-and-socket variety; unlike other joints of that
variety, its socket is not rigid. The joint is situated at the summit of the
longitudinal arch of the foot. Its maintenance in a normal position is
dependent upon the structures which protect the longitudinal arch. The plantar
calcaneonavicular (spring) ligament passes between the anterior border of the
sustentaculum tali and the navicular and is in contact with the inferomedial part
of the head of the talus. Some authors prefer to talk about the
"subastragaloid" joint, which is a large region of articulation
between the talus above and the calcaneus and the navicular below and in front.
The talus is not a keystone bone; since it is not wedged in between the
calcaneus and the navicular, free movement is possible. In the talocalcaneal
segment, the undersurface of the talus articulates with the anterior and the
posterior facets of the calcaneus. The anterior talocalcaneal joint is continuous
with the talonavicular joint. The 2 parts of the joint are separated by the
strong interosseous talocalcaneal ligament.
FIG. The 6
tarsal joints. Some of the associated ligaments also are shown.
FIG. The
ligaments and other supporting structures of the foot. (A) The right
foot seen from below. (B) The peroneus longus tendon. (C) The spring ligament
and the plantar aponeurosis.
3. The calcaneocuboid joint is a distinct
joint, formed by the anterior surface of the calcaneus, which articulates with
the posterior surface of the cuboid. Its cavity does not communicate with the
cavities of neighboring joints. It has a capsular ligament which is
strengthened inferiorly by the long and the short plantar ligaments. The long
plantar ligament, which lies superficial to the short, is attached posteriorly
to the plantar surface of the calcaneus as far forward as its anterior
tubercle. In front it attaches to the ridge of the cuboid, but some fibers are
continued onward to the bases of the 3rd, the 4th and the 5th metatarsal bones
and thus bridge over the groove in which the peroneus longus tendon lies. The short
plantar ligament is attached to a groove at the undersurface of the
calcaneus and to the ridge forming the posterior boundary of the groove on the cuboid.
The talocalcaneonavicular and the calcaneocuboid joints together form the transverse
tarsal joint. This articulation plus the talocalcaneal joint are involved
in the movements of inversion and eversion. The 2 joints which form the
transverse tarsal joint do not communicate with each other; they lie in almost
the same coronal plane. This plane is indicated by a line drawn from a point
immediately behind the tuberosity of the navicular to a point ½ inch
behind the base of the 5th metatarsal.
4. The cuneonavicular joint is formed by
the navicular bone behind and the 3 cuneiforms in front. Its cavity is
continuous with the joint cavity of the metatarsocuneiform and the
corresponding intermetatarsal joints. When the navicular and the cuboid bones
come into contact with each other, the cubocuneiform joint also is continuous
with the joint cavity of the cuneonavicular. The capsular ligament of the joint
is strengthened by the dorsal and the plantar ligaments.
5. The cubometatarsal joint articulates
with the 2 lateral metatarsal bones. In this way, the joint is placed between
the cuboid bone behind and the bases of the 4th and the 5th metatarsal bones in
front.
6. The tarsometatarsal joint exists
between the base of the big toe metatarsal and the first cuneiform. Like the
corresponding joint of the hand, it is an independent joint with a separate
synovial lining.
The tarsometatarsal joints form
an oblique line which runs laterally and backward across the foot from the 1st
to the 5th joints. Because of the shortness of the intermediate cuneiform, the
base of the 2nd metatarsal projects farther backward between the medial and the
lateral cuneiform bones, the line being interrupted at this point. The bases of the first 3 metatarsal bones articulate with the 3
cuneiform bones, and the bases of the 4th and the 5th metatarsal bones
articulate with the cuboid bone. The metatarsals are attached firmly to
the cuneiform and the cuboid bones by the dorsal, the plantar and the
interosseous ligaments.
The metatarsophalangeal joints are
formed between the heads of the metatarsal bones and the bases of the proximal
row of phalanges. The capsular ligament which surrounds the joint is attached
to the bone near the margins of the articular surface and is reinforced at the
side to form the collateral ligaments. Its plantar part is thick, forming the
so-called plantar ligament; its dorsal part is thin and is fused with the
extensor tendon, so that the latter is, in effect, the dorsal ligament of the
1st metatarsophalangeal joint.
The interphalangeal joints are
those which exist between the phalanges of the toes; they resemble those of the
fingers. The ligaments that unite them include, in addition to the articular
capsule, the collateral, the dorsal and the accessory plantar.
The ligaments which,
as a rule, unite adjacent bones are the dorsal, the plantar and the
interosseous. The plantar ligaments situated in the concavity of the arches of
the foot are stronger than the dorsal. Besides those which have been discussed
already, certain ligaments require special mention:
1. The interosseous talocalcaneal ligament is
a strong band lying in the tarsal sinus and separating the posterior
talocalcaneal joint from the talocalcaneal navicular joint.
2. The
inferior calcaneonavicular, or the so-called spring ligament,
extends from the sustentaculum tali to the navicular bone. It is situated under
the head of the talus and is an important factor in supporting the arch of the
foot.
3. The long plantar ligament is attached
posteriorly to the undersurface of the os calcis and anteriorly to the cuboid
and to the bases of the 2nd, the 3rd and the 4th metatarsals. Therefore, it
converts the groove of the peroneus longus into a canal.
4. The short plantar ligament is about
5. The bifurcate ligament, or the
so-called "Y"-shaped ligament of Chopart, arises by its stem from the
front of the upper surface of the os calcis and divides into 2 branches which
pass to the upper surfaces of the cuboid and the navicular. It crosses the line
of the Chopart amputation (intertarsal).
ARCHES The
feet have acquired arches for 4 main reasons: (1) to distribute the body weight
properly; (2) to give elasticity and spring to the step; (3) to break the shock
that results from running, walking and jumping; (4) to provide space for soft
tissues which lie in the arch and thereby prevent undue pressure. The
longitudinal and the transverse arches are described.
The longitudinal
arch is divided into 2 columns (medial column and lateral),
both of which rest on a common pillar posteriorly, namely, the tuberosity of
the calcaneus. The inner, or medial, column of the longitudinal
arch is made up of the calcaneus, the talus, the navicular, the 3 cuneiforms
and the 3 inner metatarsals. This inner arch is high and is easily seen if
normal; it is absent in individuals with flat feet but is increased in pes
cavus. It consists of more segments than the outer arch, has more elasticity
and is essentially the "arch of movement." The outer, or lateral,
column of the longitudinal arch is formed by the calcaneus, the cuboid and
the 2 outer metatarsals. This arch is low, so that the outer border of the foot
touches the ground along its entire length.
FIG. The
longitudinal arch of the foot.
The inner
arch, being high, only touches the ground behind, at the tuberosity of the
calcaneus, and in front, at the head of the first metatarsal bone (ball of the
great toe). The parts of the foot which normally bear the body weight and
transmit it to the ground are arranged in tripod fashion, at the tuberosity of
the calcaneus, the head of the 1st metatarsal and the head of the 5th metatarsal.
In the young child, the arching of the foot may be masked by a plantar fat pad,
so that the baby's foot looks flat.
The
transverse arches are a series of arches which extend
from the arch formed by the heads of the metatarsals and backward to the arch formed
by the navicular and the cuboid bones. The metatarsals and the tarsal bones are
arranged so that their convexity is on the dorsum and the concavity is on the
plantar aspect. If the transverse arch formed by the heads of the metatarsals
becomes flattened, the digital vessels and nerves which normally are protected
by it are pressed upon, and pain results. The arches must be maintained or
supported by definite structures. The supporting structures are: (1) the
muscles and the tendons, (2) the ligaments, (3) the fasciae and (4) the bones.
Supporting
Tendons. Of the tendons
which support the arches, 2 are important: the peroneus longus and the
tibialis posterior. The peroneus longus tendon passes down the lateral
side of the leg and across the lateral side of the foot, turns at right angles
on itself and continues across the sole of the foot,
from lateral to medial. In this part of its course it lies in a tunnel formed
by the cuboid and the long plantar ligament. It is inserted into the outer side
of the 1st cuneiform bone and the base of the 1st metatarsal. Therefore, it
acts as a sling for the longitudinal arch, about its middle. It also forms a
bolstering across the transverse arch, thus supporting it. As it abducts and
everts the foot, it lowers the longitudinal arch. It is believed by some
anatomists that paralysis of this muscle increases the arch. The tendon of
the tibialis posterior has its main insertion about the middle of the
longitudinal arch to the undersurface of the navicular. Additional support is
given to this arch, as it sends a tendinous slip into every bone of the tarsus
except the talus, and also the bases of the 2nd, the 3rd and the 4th metatarsal
bones. The function of the tendon of the tibialis posterior is similar to that
of the peroneus longus and balances it on the inner side. It supports the
spring ligament and adducts and inverts the foot.
Muscles. The
muscles that support the arches do so by pulling the 2 pillars of the arches
closer together or directly upward. Those muscles that adduct and invert the
foot increase the longitudinal arch, while those which abduct and evert flatten
it. Therefore, the long flexors of the toes and the short muscles of the foot
pull the pillars together and increase the arch. The short muscles can withstand
the strain better than the ligamentous structures. So powerful are these short
muscles as arch maintainers that they may increase the arch and produce a pes
cavus. The transverse arch is maintained mainly by the transverse head of the
adductor hallucis and to a lesser degree by its oblique head.
Ligaments. The
ligaments that are associated with arch support are weak over the dorsum of the
foot but are powerful over the sole. All the ligaments in this region are
important, but a few require special mention. The inferior calcaneonavicular
(spring) ligament is an important structure in the support of the
longitudinal arch. It is placed under the weakest point (the head of the talus)
and thereby prevents it from sinking between the calcaneus and the navicular.
When weight falls on the talus, this strong ligament gives a little but, being
very elastic, pushes the head of the bone immediately back into position when
the superimposed weight is removed. The long plantar ligament is a
powerful structure that is attached to the undersurface of the calcaneus and to
the inferior surface of the cuboid, whence it continues forward to the bases of
the 2nd, the 3rd and the 4th metatarsal bones. The short plantar
(calcaneocuboid) ligament passes obliquely forward and medially from the
undersurface of the calcaneus to the posterior part of the cuboid, where the
long plantar ligament conceals it. The transverse arch is maintained by the
support of the plantar intertarsal and the tarsometatarsal ligaments.
The fascia also
plays its part in supporting the arches. The intermediate portion of the plantar
aponeurosis is attached to the extremities of the arch, namely, the
posterior part of the calcaneus behind and the heads of all the metatarsals and
the proximal phalanges in front. In this way, it holds the extremities of the
arch together. The form of the bones also has a supporting value. They are
broader in the dorsum of the foot, thus making less support necessary than if
the reverse were true.
INVERSION AND EVERSION OF THE FOOT Rotating the
sole of the foot inward (inversion) around the long axis of the foot is
performed by the tibialis anterior and the posterior muscles, assisted by the
flexors of the toes. Rotating the sole outward (eversion) around the long axis
of the foot is brought about in the following way: when the foot is plantar
flexed, it is produced by the 3 peronei (longus, brevis and tertius); when the
foot is dorsiflexed, the movement is performed by the extensor digitorum
longus. This last statement may be verified if the foot is plantar flexed and
everted strongly. In this position the strain is felt on the outer side of the
leg over the perinei muscles. If the foot is everted and dorsiflexed, no strain
is felt over the peronei, but the strain is taken by the extensor longus, which
can be seen and felt. Orthopedic surgeons utilized this fact when they found
that if the extensor longus digitorum were paralyzed, the foot could be everted
in plantar flexion but not in dorsiflexion.
FIG. The toes.
TOES The toes or digits are numbered from the
medial to the lateral side. The 1st toe is called the hallux, and the 5th toe
is called the digitus minimus. The bones of the toes are the phalanges. The big
toe has only 2 – a proximal and a distal – but the others have 3 – proximal,
middle and distal. Each proximal phalanx articulates with the head of a
metatarsal bone and in this way forms the metatarsophalangeal joint. The middle
phalanx articulates with the 2 other phalanges to form the interphalangeal
joint. The proximal encTbf the phalanx is called its base, and its distal end
is called its head. The toes are involved in various conditions which will be
discussed subsequently.
SURGICAL
CONSIDERATIONS
INFECTIONS OF
THE FOOT Infections of the foot are less common than those of the hand, but
they can be approached and drained as effectively. Grodinsky has emphasized the
clinical importance of the 4 median fascial spaces on the plantar aspect of the
foot and the 2 dorsal spaces.
The 4 median
plantar spaces: 1. The first space is
located between the plantar aponeurosis and the flexor digitorum brevis.
2. The second
space is situated between the flexor digitorum brevis and the conjoined long
flexor tendons and quadratus plantae.
3. The third
space is found between the flexor digitorum longus (with its associated
lumbricales muscles) and the oblique head of the adductor hallucis.
4. The fourth
and deepest space is situated between the oblique head of the adductor hallucis
muscle and the 2nd and the 3rd metatarsal bones and their interosseous muscles.
These spaces are bounded both laterally and medially by dense connectivetissue
septa, along which an infection may travel from one space to another. There is
nothing in the foot that corresponds to the radial and the ulnar bursae of the
hand, since the sheaths of all the flexor tendons of the toes end proximal to
the distal head of the metatarsal bones; the sheath of the flexor hallucis
longus extends a little higher than the rest. Therefore, infections within
these sheaths either may remain local or break into one of the four spaces. Two
lateral spaces have been described, but these are of little anatomic or
clinical importance. The 2 dorsal spaces, subaponeurotic and
subcutaneous, are similar to those found in the hand and are treated in the
same way. Infections in any of these spaces may be the result of extension
along fascial or tendon planes or may result from direct penetrating wounds
into a given space.
Treatment. The
4 medial fascial spaces can be approached best from the inside of the foot, so
that a scar is not left on the plantar, or weight-bearing, surface. Such an
incision should be made along the inner border of the 1st metatarsal bone and
should be carried between that bone and the flexor hallucis longus muscle. This
incision follows the inferior surface of the bone and separates it from the
flexor hallucis brevis. In this way, access is gained to the septum which forms
the medial wall of all 4 spaces; the tendon of the flexor hallucis longus also
is protected. At times, a counter-incision may be necessary; if so, it is made
along the outer edge of the plantar surface.
DEFORMITIES
OF THE FOOT The general term "talipes" is used to designate foot
deformities. Four forms of talipes are described: equinus, calcaneus, valgus
and varus.
Talipes
equinus is caused by a contracted tendon of Achilles, which
prevents the foot from being placed squarely on the ground. The forepart of the
foot is in contact with the ground; in severe forms of equinus, the foot may
form almost a straight line with the leg. Usually a contracture of the plantar
aponeurosis is associated with the condition; this results in a deep hollowing
of the sole known as talipes cavus. The condition usually can be corrected by
stretching the calf muscles or by cutting the Achilles tendon.
FIG. The 4
plantar spaces of the foot. (A) Longitudinal section;
(B) cross section; (C) alternate incisions for space drainage.
FIG. Four varieties of talipes: (A) equinus; (B) calcaneus; (C) valgus;
(D) varus.
Talipes
calcaneus constitutes a dorsiflexion of the foot on the leg.
Usually, it is caused by an involvement of the calf muscles following infantile
paralysis.
In talipes
valgus, the medial border of the foot is depressed and is in contact with
the ground. If of congenital origin, the peronei are shortened, and the
anterior and the posterior tibial muscles are stretched. In the acquired form,
the deformity is brought about by a paralysis of the tibialis anterior and the
posterior muscles.
In talipes
varus, the foot is twisted on itself in a position of adduction and
inversion. The dorsum of the foot is directed somewhat forward, and the sole is
directed backward.
HALLUX VALGUS
Hallux valgus, or bunion, is a condition in which the big toe deviates
laterally, and the head of the first metatarsal becomes prominent. The joint
surface of the head of the metatarsal pushes obliquely and laterally. An
adventitious bursa, which is a bunion, usually develops over the projecting
head of the bone. Numerous operations have been devised to cure this condition;
however, their aim is essentially the same. The head of the first metatarsal is
reduced by removing part of its medial surface and reconstructing its articular
alignment. The bursa that is present usually is dissected away, and the tendon
of the extensor hallucis is displaced medially and maintained in position by
suturing, so that by its contraction the great toe is kept in alignment.
HAMMER TOE In
this condition, the involved toe contracts and produces a sharp angulation. The
toes that usually are involved are the 2nd or the 3rd. The common extensor
muscle is stretched, resulting in an elevation of the proximal phalanx but
leaving the other phalanges in flexion. The proximal interphalangeal joint is
flexed acutely, but the metatarsophalangeal and the distal interphalangeal
joints are hyperextended. The operative correction of this condition attempts
to divide the dorsal expansion of the extensor tendon which covers the dorsum
of the joint. In this way the joint is opened widely, and, after division of
the lateral ligament, the head of the first phalanx is dislocated into the
wound and is excised.
FIG. Hallux valgus.
FIG. Hammer toe.
RECOMMENDED LITERATURE:
1.
Mark W. Wolcott. Ambulatory Surgery
End The Basic Of Emergency Surgical Care.-Philadelphia:J.B.Lippincott
Company,2001.-752p.
2.
Michael F. Mulroy.Regional Anesthesia
/The
3.
Richard M. Stilman,M.D.,E.A.C.S.
General Surgery /Review And Assessment/
4.
Kent M. Van De Graff, Stuart Ira Fox,
Karen M. Lafleur. Synopsis of Human Anatomy and Physiology /WCB
McGraw-Hill/, 2004.-675p.
5.
John J. Jacobs. Shearer’s Manual Of Human Dissection /McGraw-Hill Information Services
Company, 1998.-300p.
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7.
Philip Thorek. Anatomy In Surgery
/J.B.Lippincott Company/,1996.-935p.