Pediatric fractures of the lower
extremity. Features of diagnosis and
treatment. Main principles of no operative and operative treatment in children depending on
age. Principles of rehabilitation.
Pediatric Hip
PEDIATRIC HIP FRACTURES
Epidemiology
- Hip fractures are rare in children,
occurring less than 1% as often as in adults.
Anatomy
- Ossification (Fig. 1)
- Proximal
femur: week
- Proximal femoral epiphysis: age 4 to 8
months
- Trochanter: 4 years
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Figure 1. The transformation of the
preplate to separate growth zones for the femoral head and greater
trochanter. The diagram shows development of the epiphyseal nucleus in the
proximal end of the femur. (A) X-ray of the proximal end of the femur of a
stillborn girl, weight (From Edgren W. Coxa plana: a clinical and radiological investigation with particular reference to the importance of the metaphyseal changes for the final shape of the proximal part of the femur. Acta Orthop Scand 1965;84(suppl):24.) |
- The proximal femoral epiphysis fuses by
age 18 years, the trochanteric apophysis by age 16 to 18 years.
- The proximal femoral physis contributes
significantly to metaphyseal growth of the femoral neck and less to
primary appositional growth of the femoral head. Thus, disruptions in this
region may lead to architectural changes that may affect the overall
anatomic development of the proximal femur.
- The trochanteric apophysis contributes
significantly to appositional growth of the greater trochanter and less to
the metaphyseal growth of the femur.
- Blood is supplied to the hip by the lateral femoral circumflex artery and, more importantly, the medial femoral circumflex artery. Anastomoses at the anterosuperior portion of the intertrochanteric groove form the extracapsular ring. Ascending retinacular vessels go to the epiphysis (Fig. 2).
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Figure 2. Arterial supply of the proximal femur. The capital femoral
epiphysis and physis are supplied by the medial circumflex artery through two
retinacular vessel systems: the posterosuperior and posteroinferior. The
lateral circumflex artery supplies the greater trochanter and the lateral
portion of the proximal femoral physis and a small area of the anteromedial
metaphysis. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
- By 3 or 4 years of age, the lateral
posterosuperior vessels (branches of the medial femoral circumflex) predominate
and supply the entire anterolateral portion of the capital femoral
epiphysis.
- Vessels of the ligamentum teres contribute
little before age 8 years and approximately 20% in adulthood.
- Capsulotomy does not damage the blood
supply to the femoral head, but violation of the intertrochanteric notch
or the lateral ascending cervical vessels can render the femoral head
avascular.
Mechanism of Injury
- Axial
loading, torsion, hyperabduction, or a direct blow can result in a hip
fracture. Severe, direct trauma (e.g., motor vehicle accident) accounts
for 75% to 80% of pediatric hip fractures.
- Pathologic:
Fracture occurs through bone cyst, fibrous dysplasia, or tumor.
- Stress
fractures: These are uncommon.
Clinical Evaluation
- The
patient typically presents with a shortened and externally rotated lower
extremity.
- Range
of hip motion is painful with variable crepitus.
- Swelling, ecchymosis, and tenderness to palpation are generally
present over the injured hip. A careful neurovascular examination should
be performed.
Radiographic Evaluation
- Anteroposterior (AP) views of the pelvis
and a cross-table lateral view of the affected hip should be obtained,
with the leg extended and internally rotated as far as is tolerable by the
patient.
- Developmental coxa vara should not be
confused with hip fracture, especially in patients <5 years of age.
Comparison with the contralateral hip may aid in the distinction.
- Computed tomography may aid in
the diagnosis of nondisplaced fractures or stress fractures.
- A radioisotope bone scan obtained 48 hours
after injury may demonstrate increased uptake at the occult fracture site.
- Magnetic resonance imaging may detect
occult fractures within 24 hours of injury.
Classification
Delbert
Classification of Pediatric Hip Fractures (Fig. 3)
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Figure 3. Delbet classification of hip fractures in children. Type I,
transepiphyseal, with (Type IB) or without ( (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
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Treatment |
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Closed reduction with pin fixation is
indicated, using threaded pins in an older child and smooth pins in a younger
child. Open reduction and internal fixation may be necessary if the fracture
is irreducible by closed methods. |
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Type II: |
Nondisplaced: The choice is abduction spica
cast versus in situ pinning; these fractures may go on to coxa vara or
nonunion. Displaced: Closed reduction and pinning (open reduction if
necessary) are indicated; transphyseal pinning should be avoided. |
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Type III: |
Nondisplaced: Traction is indicated, then
spica cast versus immediate abduction spica versus in situ pinning.
Displaced: Open reduction and internal fixation are recommended, with
avoidance of transphyseal pinning. |
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Type IV: |
Two to 3 weeks of traction are indicated,
then abduction spica for 6 to 12 weeks. Open reduction and internal fixation
may be necessary for unstable fractures or if one is unable to achieve closed
reduction. |
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Complications
- Osteonecrosis: The overall incidence is 40% after pediatric hip fracture. This is directly related to initial fracture displacement and fracture location. Ratliff described three types (Fig. 4):
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Figure 47.4. Three types of osteonecrosis. (From Ratliff AHC. Fractures of the neck of the femur in children. J Bone Joint Surg Br 1962;44:528.) |
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Diffuse, complete head involvement, and
collapse; poor prognosis (60%) |
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Type II: |
Localized head involvement only; minimal
collapse (22%) |
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Type III: |
Femoral neck involved only; head sparing
(18%) |
- Premature
physeal closure: The incidence is ≤60%, with increased
incidence with pins penetrating the physis. It may result in femoral
shortening, coxa vara, and short femoral neck. The proximal femoral
epiphysis contributes to only 15% of growth of the entire lower extremity.
The presence of premature physeal closure in association of osteonecrosis
may result in significant leg length discrepancy.
- Coxa
vara: The incidence is 20%, usually secondary to inadequate reduction.
Open reduction and internal fixation are associated with a reduced
incidence of coxa vara.
- Nonunion:
The incidence is 10%, primarily owing to inadequate reduction or
inadequate internal fixation. It may require valgus osteotomy with or
without bone graft to achieve union.
DISLOCATION OF THE HIP
Epidemiology
- More common than hip fractures.
- Bimodal distribution: The incidence is
greater between 2 and 5 years, owing to joint laxity and soft pliable
cartilage, and between 11 and 15 years of age as athletic injuries and
those associated with vehicular trauma become more common.
- Posterior dislocations: These occur ten
times more frequently than anterior dislocations.
Mechanism of Injury
- Younger
patients (age <5 years): may occur with relatively insignificant trauma
such as a fall from a standing height.
- Older
patients (>11 years): These injuries tend to occur with athletic
participation and vehicular accidents (bicycles, automobiles, etc.). In
this age group, there is a higher association with acetabular fractures.
- Posterior
dislocations are usually the result of an axial load applied to a flexed and
adducted hip; anterior dislocations occur with a combination of abduction
and external rotation.
Clinical Evaluation
- In
cases of posterior hip dislocation, the patient typically presents with
the affected hip flexed, adducted, and internally rotated. Anterior hip
dislocation typically presents with extension, abduction, and external
rotation of the affected hip.
- A
careful neurovascular examination is essential, with documentation of
integrity of the sciatic nerve and its branches in posterior dislocations.
Femoral nerve function and limb perfusion should be carefully assessed in
anterior dislocations. This examination should be repeated after closed
reduction.
- Ipsilateral
femur fracture often occurs and must be ruled out before hip manipulation.
Radiographic Evaluation
- AP views of the pelvis and a lateral view
of the affected hip should be obtained. Pain, swelling, or obvious
deformity in the femoral region is an indication for femoral radiographs,
to rule out associated fracture.
- Fracture fragments from the femoral head
or acetabulum are typically more readily appreciated on radiographs
obtained after reduction of the hip dislocation because anatomic landmarks
are more clearly delineated.
- Following reduction, computed tomography
should be obtained to delineate associated femoral head or acetabular
fracture, as well as the presence of interposed soft tissue.
Classification
Descriptive
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Anterior
versus posterior |
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Fracture-dislocation: |
Fractures to the femoral head or acetabulum |
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Associated injuries: |
Presence of ipsilateral femur fracture, etc. |
Treatment
Nonoperative
- Closed
reduction using conscious sedation may be performed for patients
presenting less than 12 hours after dislocation.
- Skeletal
traction may be used for reduction of a chronic or neglected hip
dislocation, with reduction taking place over a 3- to 6-day period and
continued traction for an additional 2 to 3 weeks to achieve stability.
Operative
- Dislocations
more than 12 hours old may require reduction with the patient under
general anesthesia. Open reduction may be necessary, if irreducible, with
surgical removal of interposing capsule, inverted limbus, or
osteocartilaginous fragments.
- Open
reduction is also indicated in cases of sciatic nerve compromise in which
surgical exploration is necessary.
- Hip
dislocations associated with ipsilateral femoral shaft fractures should
initially be addressed with reduction of the dislocation. If manipulative
closed reduction is unsuccessful, skeletal traction may be applied to the
trochanteric region to allow control of the proximal fragment. Internal or
external fixation of the femoral shaft fracture may then be performed.
Occasionally, operative fixation of the femoral shaft fracture is
necessary to achieve stable reduction of the hip.
- Postoperatively,
the patient should be placed in skeletal traction or spica cast for 4 to 6
weeks to achieve hip stability.
Complications
- Osteonecrosis (8% to 10%): This has a
decreased incidence with patient age <5 years and an increased
incidence with severe displacement and delay in reduction.
- Epiphyseal separation: Traumatic physeal
injury may occur at the time of dislocation and may result in
osteonecrosis.
- Recurrent dislocation: In traumatic cases,
it may result from absolute capsular tears or capsular attenuation. It is
also associated with hyperlaxity or congenital syndromes (e.g., Down
syndrome). It may be addressed with surgical “tightening†of the hip, with capsular
repair, or with plication as well as spica casting for 4 to 6 weeks
postoperatively.
- Degenerative joint disease: This may
result from nonconcentric hip reduction secondary to trapped soft tissue
or bony fragments or from the initial trauma. Articular incongruity
secondary to associated femoral head or acetabular fracture, or entrapped
osteochondral fragments, may exacerbate degenerative processes.
- Nerve injury (2% to 13%): Sciatic nerve
injury can occur with posterior dislocation and is typically a stretch
injury. Treatment is usually expectant, unless laceration or incarceration
in the joint is suspected.
- Chondrolysis (6%): Injury occurs at the
time of hip dislocation. Management is symptomatic treatment with nonsteroidal
antiinflammatory drugs and weight-relieving devices as needed.
Pediatric Femoral Shaft
EPIDEMIOLOGY
- Represent 1.6% of all fractures in the
pediatric population.
- Boys are more commonly affected at a ratio
of 2.6:1.
- Bimodal distribution of incidence: The
first peak is from 2 to 4 years of age, and the second is in
mid-adolescence.
- There is also a seasonal distribution,
with a higher incidence during the summer months.
- In children younger than walking age, 80%
of these injuries are caused by child abuse; this decreases to 30% in
toddlers.
- In adolescence, >90% of femoral
fractures are caused by motor vehicle accident.
ANATOMY
- During childhood, remodeling in the femur
causes a change from primarily weaker woven bone to stronger lamellar
bone.
- Up to age 16 years, there is a geometric
increase in the femoral shaft diameter and relative cortical thickness of
the femur, resulting in a markedly increased area moment of inertia and
strength. This partially explains the bimodal distribution of injury
pattern, in which younger patients experience fractures under load
conditions reached in normal play or minor trauma, whereas in adolescence
high-energy trauma is required to reach the stresses necessary for
fracture (Fig. 5).
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Figure 5. The shaded area represents cortical thickness by
age group. This rapid increase in cortical thickness may contribute to the
diminishing incidence of femoral fractures during late childhood. (Redrawn
from Netter FH. The Ciba collection
of medical illustrations. Vol. 8. Musculoskeletal
system. |
MECHANISM OF INJURY
- Direct
trauma: Motor vehicle accident, pedestrian injury, fall, and child abuse
are causes.
- Indirect trauma: Rotational
injury.
- Pathologic
fractures: Causes include osteogenesis imperfecta, nonossifying fibroma,
bone cysts, and tumors. Severe involvement from myelomeningocele or
cerebral palsy may result in generalized osteopenia and a predisposition
to fracture with minor trauma.
CLINICAL EVALUATION
- Patients
with a history of high-energy injury should undergo full trauma evaluation
as indicated.
- The
presence of a femoral shaft fracture results in an inability to ambulate,
with extreme pain, variable swelling, and variable gross deformity. The
diagnosis is more difficult in patients with multiple trauma or head
injury or in nonambulatory, severely disabled children.
- A
careful neurovascular examination is essential.
- Splints
or bandages placed in the field must be removed with a careful examination
of the overlying soft tissues to rule out the possibility of an open
fracture.
- Hypotension
from an isolated femoral shaft fracture is uncommon. The Waddell triad of
head injury, intraabdominal or intrathoracic trauma, and femoral shaft
fracture is strongly associated with vehicular trauma
and is a more likely cause of volume loss. However, the presence of a
severely swollen thigh may indicate large volume loss into muscle
compartments surrounding the fracture.
- Compartment
syndrome is rare and occurs only with severe hemorrhage into thigh
compartments.
- The
ipsilateral hip and knee should be examined for associated injuries.
RADIOGRAPHIC EVALUATION
- Anteroposterior and lateral views of the
femur should be obtained.
- Radiographs of the hip and knee should be
obtained to rule out associated injuries; intertrochanteric fractures,
femoral neck fractures, hip dislocation, physeal injuries to the distal
femur, ligamentous disruptions, meniscal tears, and tibial fractures have
all been described in association with femoral shaft fractures.
- Magnetic resonance imaging and bone scans
are generally unnecessary but may aid in the diagnosis of otherwise occult
nondisplaced, buckle, or stress fractures.
Descriptive
- Open versus closed
- Level
of fracture: proximal, middle, distal third
- Fracture
pattern: transverse, spiral, oblique, butterfly fragment
- Comminution
- Displacement
- Angulation
Anatomic
- Subtrochanteric
- Shaft
- Supracondylar
TREATMENT
Treatment
is age dependent, with considerable overlap among age groups. The size of the
child must be considered when choosing a treatment method, as well as the
mechanism of the injury (i.e., isolated, low-energy versus high-energy
polytrauma).
Age
<6 Months
- Pavlik
harness or a posterior splint is indicated.
- Traction
and spica casting are rarely needed in this age group.
Ages
6 Months to 6 Years
- Immediate
spica casting is nearly always the treatment of choice (>95%).
- Skeletal
traction followed by spica casting may be needed if one is unable to
maintain length and acceptable alignment; a traction pin is preferably
placed proximal to the distal femoral physis.
- External
fixation may be considered for multiple injuries or open fracture.
Ages
6 to 12 Years
- Flexible
intramedullary nails placed in a retrograde fashion are frequently used in
this age group.
- External
fixation or bridge plating may be considered for multiple injuries or open
fracture.
- Some
centers are using interlocked nails inserted through the greater
trochanter (controversial).
- Spica
casting may be used for the axially stable fractures in this age group.
Ages
12 to Maturity
- Intramedullary
fixation with either flexible or interlocked nails is the treatment of
choice.
- Locked
submuscular plates may be considered for supracondylar or subtrochanteric
fractures.
- External
fixation may be considered for multiple injuries or open fracture.
Reduction Criteria (Table 48.1)
- Length
- Ages 2 to 11 years: Up to
- Age >11 years: Up to
- Angulation
- Sagittal plane: Up to 30 degrees of
recurvatum/procurvatum is acceptable.
- Frontal plane: Up to 10 degrees of
varus/valgus angulation is acceptable (varus commonly seen with spica
casting).
- This varies with pattern, age, and
location of fracture along the femur.
- Rotation
- Up to 10 degrees is acceptable; external
rotation is better tolerated than internal rotation.
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Table 48.1. Acceptable angulation |
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Operative Indications
- Multiple trauma, including
head trauma
- Open fracture
- Vascular injury
- Pathologic fracture
- Uncooperative patient
- Body
habitus not amenable to spica casting
Operative Options
- Intramedullary nailing
- Flexible
nails: These are inserted retrograde proximal to the distal femoral
physis.
- Reamed,
locked intramedullary nails: These are placed antegrade through the
piriformis fossa or greater trochanter. The distal physis should not be
traversed. A piriformis entry point is not recommended for patients
<12 years old (proximal femoral physis open), because proximal femoral
growth abnormalities and osteonecrosis of the femoral head owing to
disruption of the vascular supply are possible complications. A
trochanteric entry point theoretically reduces the risk of osteonecrosis.
- External fixation
- Lateral,
unilateral frame: This spares the quadriceps mechanism.
- This
approach is useful in multiple trauma, especially in those who are
hemodynamically unstable, have open fractures or burn patients.
- Plate fixation
- This
may be accomplished using a 3.5 or
- Submuscular
locking plates are useful for supracondylar and subtrochanteric fractures
in which intramedullary devices have limited fixation. Less soft tissue
stripping needed, but infection and plate removal remain concerns.
COMPLICATIONS
- Malunion: Remodeling will not correct
rotational deformities. An older child will not remodel as well as a
younger child. Anteroposterior remodeling occurs much more rapidly and
completely in the femur than varus/valgus angular deformity. For this
reason, greater degrees of sagittal angulation are acceptable.
- Nonunion: Rare; even with segmental
fractures, children often have sufficient osteogenic potential to fill
moderate defects. Children 5 to 10 years of age with established nonunion
may require bone grafting and plate fixation, although the trend in older
(>12 years) children is locked intramedullary nailing.
- Muscle weakness: Many patients demonstrate
weakness, typically in hip abductors, quadriceps, or hamstrings, with up
to a 30% decrease in strength and
- Leg length discrepancy: Secondary to
shortening or overgrowth. It represents the most common complication after
femoral shaft fracture.
- Overgrowth: Overgrowth of 1.5 to
- Shortening: Up to
- Osteonecrosis: Proximal femoral
osteonecrosis may result from antegrade placement of an intramedullary
nail owing to the precarious vascular supply. This is of particular
concern when the proximal femoral physis is not yet closed, because the
major vascular supply to the femoral head is derived from the lateral
ascending cervical artery, which crosses the capsule at the level of the
trochanteric notch. Recently, intramedullary nails with a trochanteric
starting point have been advocated to reduce the risk of osteonecrosis.
Radiographic changes may be seen as late as 15 months after antegrade
intramedullary nailing.
Pediatric Knee
Overview
- The knee is a ginglymoid (hinge) joint
consisting of three articulations: patellofemoral, tibiofemoral, and
tibiofibular.
- Under normal cyclic loading, the knee may
experience up to five times body weight per step.
- The normal range of motion is from 10
degrees of extension to 140 degrees of flexion, with 8 to 12 degrees of
rotation through the flexion/extension arc.
- The dynamic and static stability of the
knee is conferred mainly by soft tissues (ligaments, muscles, tendons,
menisci) in addition to the bony articulations.
- Because ligaments in the immature skeleton
are more resistant to tensile stresses than are physeal plates, trauma
leads to physeal separation and avulsions not seen in the skeletally
mature patient.
- There are three physeal plates with
secondary ossification centers.
- Appearance of ossification centers is as
follows:
- Distal femur: thirty-ninth fetal week
- Proximal tibia: by 2 months
- Tibial tubercle: 9 years
- Physeal closure is as follows:
- Distal femur: 16 to 19 years
- Proximal tibia: 16 to 19 years
- Tibial tubercle: 15 to 17 years
- The patella is a sesamoid bone, with its
own ossification center, which appears at age 3 to 5 years.
- Tibial spine: This is the site of
insertion of the anterior cruciate ligament (ACL).
- Two-thirds of longitudinal growth of the
lower extremity is provided by the distal femoral (9 mm/year) and proximal
tibial (6 mm/year) physes.
DISTAL FEMORAL FRACTURES
Epidemiology
- The most commonly injured physis around the
knee.
- These comprise 1% to 6% of all physeal
injuries and less than 1% of all fractures in children.
- Most (two-thirds) are Salter-Harris Type
II fractures and occur in adolescents.
Anatomy
- The distal femoral epiphysis is the
largest and fastest growing physis in the body.
- There is no inherent protection of the
physis; ligamentous and tendinous structures insert on the epiphysis.
- The sciatic nerve divides at the level of
the distal femur.
- The popliteal artery gives off
the superior geniculate branches to the knee just posterior to the femoral
metaphysis.
Mechanism of Injury
- Direct
trauma to the distal femur: Uncommon, but it may occur from vehicular
trauma, falling onto a flexed knee, or during athletic activity, such as a
lateral blow to the knee with a planted, cleated foot in football. In
infants, this injury must be suspected to be the result of child abuse.
- Indirect
injury: Varus/valgus or hyperextension/hyperflexion; it usually results in
simultaneous compression to one aspect of the physis with distraction to
the other, with the epiphysis separating from the metaphysis owing to
tension. Most typically, the physeal separation begins on the tension side
and exits the metaphysis on the compression side (Salter-Harris Type II).
- Birth
injury secondary to breech presentation or arthrogryposis may cause this
injury.
- Minimal
trauma in conditions that cause generalized weakening of the growth plate
(osteomyelitis, leukemia, myelodysplasia) may also be causative.
Clinical Evaluation
- Patients
are typically unable to bear weight on the injured lower extremity,
although patients with a nondisplaced physeal injury from a low-energy
mechanism (e.g., athletic injury) may ambulate with an antalgic gait.
- Older
children and adolescents may relate a history of hearing or feeling a “pop;†along with associated knee effusion and
soft tissue swelling, this may be confused with a ligamentous injury.
- The
knee is typically in flexion owing to hamstring spasm.
- Gross
shortening or angular deformity is variable, with potential compromise of
neurovascular status resulting from traction injury or laceration. A complete
neurovascular assessment is thus critical.
- Point
tenderness may be elicited over the physis; this is usually performed by
palpating the distal femur at the level of the superior pole of the
patella and adductor tubercle.
- Most
commonly, epiphyseal displacement is in the coronal plane producing
varus/valgus deformity.
Radiographic Evaluation (Table 1)
- Anteroposterior (AP), lateral, and oblique
views should be obtained. Radiographs of the contralateral lower extremity
may be obtained for comparison.
- Stress views may be obtained to diagnose
nondisplaced separations in which the clinical examination is highly
suggestive of physeal injury (knees with effusion and point tenderness
over physis in setting of negative AP and lateral x-rays). Adequate
analgesia is necessary to relax muscular spasm and to prevent both
false-negative stress radiographs and physeal injury.
- The physeal line should be 3 to
- Salter-Harris Type III injuries usually
have vertically oriented epiphyseal fracture components that are best
appreciated on an AP view.
- Computed tomography may be useful to
assess articular involvement or to aid in fracture definition.
- In infants, separation of the
distal femoral physis may be difficult to assess unless there is gross
displacement because only the center of the epiphysis is ossified at
birth; this should be in line with the anatomic axis of the femur on both
AP and lateral views. Magnetic resonance imaging, ultrasound, or
arthrography may aid in the diagnosis of distal femoral injury in these
patients.
- Arteriography of the lower extremity
should be pursued if vascular injury is suspected.
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Table 1. Imaging studies in the
evaluation of distal femoral physeal fractures |
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Classification
Salter-Harris (Fig. 6)
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Seen in newborns and adolescents; diagnosis
easily missed; physeal widening may be demonstrated on stress radiographs |
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Type II: |
Most common injury of the distal femoral
physis; displacement usually medial or lateral, with metaphyseal fragment on
compression side |
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Type III: |
Intraarticular fracture exiting the epiphysis
(typically medial condyle from valgus stress |
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Type IV: |
Intraarticular fracture exiting the
metaphysis; high incidence of growth inhibition with bar formation; rare
injury |
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Type V: |
Physeal crush injury; difficult diagnosis,
made retrospectively after growth arrest; narrowing of physis possible |
Displacement
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Figure 6. The Salter-Harris classification of fractures involving the distal
femoral physis.
(From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
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Results from hyperextension injury; high
incidence of neurovascular injury from proximal metaphyseal spike driven
posteriorly |
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Posterior: |
Rare injury caused by knee hyperflexion |
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Medial: |
Valgus force most common, usually
Salter-Harris Type II |
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Lateral: |
Varus
force |
Treatment
Nonoperative
·
Indicated for nondisplaced fractures.
·
A tense effusion may be addressed
with sterile aspiration for symptomatic relief.
·
Closed reduction using general
anesthesia may be performed for displaced fractures in which a stable result
can be obtained (Fig. 7).
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Figure 7. Closed reduction and stabilization of a Salter-Harris Type I or II
distal femur fracture. (A) With medial or lateral displacement, traction is
applied longitudinally along the axis of the deformity to bring the fragments
back to length. (B) For anterior displacement, the reduction can be done with
the patient prone or supine. Length is gained first, then a flexion moment is
added. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
·
Sufficient traction should be
applied during manipulation to minimize grinding of physeal cartilage (90%
traction, 10% leverage). The position of immobilization varies with direction
of displacement:
o
Medial/lateral: Immobilize in 15
to 20 degrees of knee flexion. Cast in valgus mold for medial metaphyseal
fragment and varus mold for lateral metaphyseal fragment to tension intact
periosteum.
o
Anterior: Immobilize initially at
90 degrees of knee flexion, then decrease flexion with time.
o Posterior: Immobilize in
extension.
·
A residual varus/valgus deformity
after reduction tends not to remodel.
·
Crutch ambulation with toe-touch
weight bearing may be instituted at 3 to 6 weeks after injury.
·
The cast may be discontinued at 4
to 8 weeks depending on the patient age and healing status. A removable
posterior splint and active range-of-motion exercises are instituted at this
time.
·
Athletic involvement should be
restricted until knee range of motion has returned, symptoms have resolved, and
sufficient quadriceps strength has been regained.
Operative
- Indications
for open reduction and internal fixation include:
- Irreducible
Salter-Harris Type II fracture with interposed soft tissue: Cannulated
4.0- or 6.5-mm screw fixation may be used to secure the metaphyseal spike
(Fig. 8).
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Figure 8. Screw fixation following closed or open reduction of a Salter-Harris
Type II fracture with a large metaphyseal fragment. (A) When using cannulated
screws, place both guide wires before screw placement to avoid rotation of
the fragment while drilling or inserting screw. Screw threads should be past
the fracture site to enable compression. Washers help increase compression.
Screws may be placed anterior and posterior to each other, which is
particularly helpful when trying to fit multiple screws in a small
metaphyseal fragment. (B) This form of fixation is locally “rigid,†but it must be protected with
long leg immobilization or long lever arm. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
- Unstable reduction.
- Salter-Harris
Type III, IV: Joint congruity must be restored.
- To
minimize residual deformity and growth disturbance, certain guidelines
should be observed for internal fixation
- Avoid
crossing the physis if possible.
- If
the physis must be crossed, use smooth pins as perpendicular as possible
to the physis.
- Remove
fixation that crosses the physis as soon as possible.
- Postoperatively,
the patient is maintained in a long leg cast in 10 degrees of knee
flexion. The patient may be ambulatory with crutches in 1 to 2 days with
non–weight bearing on the injured extremity. At 1 week, the patient may
begin straight leg raises.
- If
at 4 weeks evidence of osseous healing is demonstrated radiographically,
the cast may be discontinued with a posterior splint in place for
protection. The patient may be advanced to partial weight bearing with
active range-of-motion exercises.
- The
patient typically resumes a normal, active lifestyle at 4 to 6 months
after injury.
Complications
Acute
- Popliteal artery injury (<2%):
Associated with hyperextension or anterior epiphyseal displacement
injuries in which a traction injury may be sustained or by direct
laceration from the sharp metaphyseal spike.
- A cool, pulseless foot that
persists despite reduction should be worked up with angiography to rule
out laceration.
- Vascular impingement that resolves
following reduction should be observed for 48 to 72 hours to rule out an
intimal tear and thrombosis.
- Peroneal nerve palsy (3%): Caused by
traction injury during fracture or reduction or secondary to initially anterior/medial
displaced epiphysis. Persistent peroneal palsy over 3 to 6 months should
be evaluated by electromyography, with possible exploration as indicated.
- Recurrent displacement: Fractures of questionable stability following closed reduction should receive operative fixation (either percutaneous pins or internal fixation) to prevent late or recurrent displacement. Anterior and posterior displacements are particularly unstable.
Late
- Knee instability (up to 37% of patients):
Knee instability may be present, indicating concomitant ligamentous
compromise that was not appreciated at the time of index
presentation. The patient may be treated with rehabilitation for lower
extremity strengthening or may require operative treatment. Collateral
ligaments may be acutely repaired if instability exists after fixation.
- Angular deformity (19%): Results from the
initial physeal injury (Salter-Harris Types I, II), asymmetric physeal
closure (bar formation, Salter-Harris Type III, IV), or unrecognized
physeal injury (Salter-Harris Type V).
- Observation, physeal bar excision
(<30% of physis, >2 years of remaining growth), hemiepiphysiodesis,
epiphyseolysis, or wedge osteotomy may be indicated.
- Leg length discrepancy (24%): Usually
clinically insignificant if <2 years of growth remain; otherwise, the
discrepancy tends to progress at the rate of
- Discrepancy <
- Discrepancy of 2.5 to
- Discrepancy >
- Knee stiffness (16%): Results from
adhesions or capsular or muscular contracture. It is usually related to
the duration of immobilization; therefore, early discontinuation of the
cast with active range of motion is desirable.
PROXIMAL TIBIAL FRACTURES
Epidemiology
- Comprise 0.6% to 0.8% of all physeal
injuries.
- Average age is 14 years.
- Most occur in adolescent boys.
Anatomy
- The popliteal artery traverses the
posterior aspect of the knee and is tethered to the knee capsule by
connective tissue septa posterior to the proximal tibia. The vascular
supply is derived from the anastomosis of the inferior geniculate
arteries.
- The physis is well protected by osseous
and soft tissue structures, which may account for the low incidence of
injuries to this structure.
- Lateral: fibula
- Anterior: patellar tendon/ligament
- Medial: medial collateral ligament (MCL;
inserts into metaphysis)
- Posteromedial: semimembranosus insertion
Mechanism of Injury
- Direct:
Trauma to the proximal tibia (motor vehicle bumper, lawnmower accident).
- Indirect:
More common and involves hyperextension, abduction, or hyperflexion from
athletic injury, motor vehicle accident, fall, or landing from a jump with
a concurrent MCL tear.
- Birth
injury: Results from hyperextension during breech delivery or
arthrogryposis.
- Pathologic
condition: Osteomyelitis of the proximal tibia and myelomeningocele are
causes.
Clinical Evaluation
- Patients
typically present with an inability to bear weight on the injured
extremity. The knee may be tense with hemarthrosis, and extension is
limited by hamstring spasm.
- Tenderness
is present 1 to
- Neurovascular
status should be carefully assessed for popliteal artery or peroneal nerve
compromise. The anterior, lateral, superficial posterior, and deep
posterior compartments should be palpated for pain or turgor. Patients
suspected of having elevated compartment pressures should receive serial
neurovascular examinations with measurement of compartment pressures as
indicated.
- Associated
ligamentous injuries should be suspected, although it may be difficult to
appreciate these injuries secondary to the dramatic presentation of the
fracture.
Radiographic Evaluation
- AP, lateral, and oblique views of the
affected knee should be obtained. Radiographs of the contralateral knee
may be obtained for comparison.
- Stress radiographs in coronal and sagittal
planes may be obtained, but hyperextension of the knee should be avoided
because of potential injury to popliteal structures.
- Most patients with proximal tibial physeal
injuries are adolescents in whom the secondary ossicle of the tibial
tubercle has appeared. A smooth, horizontal radiolucency at the base of
the tibial tubercle should not be confused with an epiphyseal fracture.
- Magnetic resonance imaging may aid in
identification of soft tissue interposition when reduction is difficult or
impossible.
- Computed tomography may aid in fracture
definition, especially with Salter-Harris Type III or IV fractures.
- Arteriography may be indicated in patients
in whom vascular compromise (popliteal) is suspected.
Classification (Table 49.2)
Salter-Harris
|
Table 49.2. Classifications and
implications of proximal tibial physeal fractures |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
|
Transphyseal injury; diagnosis often missed;
may require stress or comparison views; 50% initially nondisplaced. |
|||||||||||||||||||||||||
|
Type II: |
Most common; transphyseal injury exiting the
metaphysis; one-third nondisplaced; those that displace usually do so
medially into valgus |
||||||||||||||||||||||||
|
Type III: |
Intraarticular fracture of the lateral
plateau; MCL often torn |
||||||||||||||||||||||||
|
Type IV: |
Intraarticular fracture of the medial or
lateral plateau; fracture line exiting the metaphysis |
||||||||||||||||||||||||
|
Type V: |
Crush injury; retrospective diagnosis common
after growth arrest |
||||||||||||||||||||||||
Treatment
Nonoperative
- Nondisplaced
fractures may be treated with a long leg cast with the knee flexed to 30
degrees. The patient should be followed closely with serial radiographs to
detect displacement.
- Displaced
fractures may be addressed with gentle closed reduction, with limited
varus and hyperextension stress to minimize traction to the peroneal nerve
and popliteal vasculature, respectively. The patient is placed in a long
leg cast in flexion (typically 30 to 60 degrees, depending on the position
of stability).
- The
cast may be discontinued at 4 to 6 weeks after injury. If the patient is
symptomatically improved and radiographic evidence of healing is
documented, active range-of-motion and quadriceps strengthening exercises
are initiated.
Operative
- Commonly,
displaced Salter Type I or II fractures in which stable reduction cannot
be maintained may be treated with percutaneous smooth pins across the
physis (Type I) or parallel to the physis (metaphysis) in Type II.
- Open
reduction and internal fixation are indicated for displaced Salter-Harris
Types III and IV to restore articular congruity.
This may be achieved with pin or screw fixation parallel to the physis;
articular congruity is the goal.
- Postoperatively,
the patient is immobilized in a long leg cast with the knee flexed to 30
degrees. This is continued for 6 to 8 weeks, at which time the cast may be
removed with initiation of active range-of-motion exercises.
Complications
Acute
- Recurrent displacement: This may occur if
closed reduction and casting without operative fixation are performed on
an unstable injury. It is likely secondary to a lack of collateral
ligamentous attachment to the epiphysis.
- Popliteal artery injury (10%): This occurs
especially in hyperextension injuries; it is related to tethering of the
popliteal artery to the knee capsule posterior to the proximal tibia (Fig. 49.4). Arteriography may be indicated when distal
pulses do not return following prompt reduction of the injury.
- Peroneal nerve palsy: This traction injury
results from displacement, either at the time of injury or during
attempted closed reduction, especially with a varus moment applied to the
injury site.
|
|
|
Figure 9. Posterior displacement of the epiphysis following
fracture-separation at the time of injury can cause arterial injury. In
addition, a posteriorly displaced fragment can cause persistent arterial
occlusion by direct pressure. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
Late
- Angular deformity: Results from the
initial physeal injury (Salter-Harris Types I, II), asymmetric physeal
closure (bar formation, Salter-Harris Type III, IV), or unrecognized
physeal injury (Salter-Harris Type V). However, Salter-Harris
classification has shown to be not useful in predicting growth disturbance
in proximal tibial fracture types.
- Observation, physeal bar excision
(<30% of physis, >2 years of remaining growth), hemiepiphysiodesis,
epiphyseolysis, or wedge osteotomy may be indicated.
- Leg length discrepancy: This is usually
clinically insignificant if <2 years of growth remain; otherwise,
discrepancy tends to progress at the rate of
TIBIAL TUBERCLE FRACTURES
Epidemiology
- Represent 0.4% to 2.7% of all physeal
injuries.
- They are seen most commonly in athletic
boys 14 to 16 years old.
- It is important to differentiate these
fractures from Osgood-Schlatter disease.
Anatomy (Fig. 10)
|
|
|
Figure 10. Development of the tibial tubercle. (A) In the cartilaginous
stage, no ossification center is present in the cartilaginous anlage of the
tibial tubercle. (B) In the apophyseal stage, the secondary
ossification center forms in the cartilaginous anlage of the tibial tubercle.
(C) In the epiphyseal stage, the primary and secondary ossification
centers of the proximal tibial epiphysis have coalesced. (D) In the bony stage, the proximal
tibial physis has closed. (From Rockwood CA Jr, Wilkins KE, Beaty JH, eds. Rockwood and Green’s Fractures in Children, 4th ed, vol. 3. Philadelphia: Lippincott-Raven, 1996:1274.) |
- The tibial tubercle physis, which is
continuous with the tibial plateau, is most vulnerable between the ages of
13 and 16 years, when it closes from posterior to anterior.
- The insertion of the medial retinaculum
extends beyond the proximal tibial physis into the metaphysic; therefore,
after tibial tubercle fracture, limited active extension
of the knee is still possible, although patella alta and extensor lag are
present.
- The tubercle is located one to two
fingerbreadths below the joint line. It is in line with the medial patella
in flexion and the lateral patella in extension.
Mechanism of Injury
- The
mechanism of injury is typically indirect, usually resulting from a sudden
accelerating or decelerating force involving the quadriceps mechanism.
- Predisposing factors
include:
- Patella baja.
- Tight
hamstrings (increase flexion torque).
- Preexisting
Osgood-Schlatter disease (uncertain whether mechanical vulnerability or
overdevelopment of quadriceps mechanism).
- Disorders with physeal
anomalies.
Clinical Evaluation
- Patients
typically present with a limited ability to extend the knee as well as an
extensor lag. The leg is held in 20 to 40 degrees of flexion by spastic
hamstrings.
- Swelling
and tenderness over the tibial tubercle are typically present, often with
a palpable defect.
- Hemarthrosis is variable.
- Patella
alta may be observed if displacement is severe.
Radiographic Evaluation
- AP and lateral views of the knee are
sufficient for the diagnosis, although a slight internal rotation view
best delineates the injury because the tibial tubercle lies just lateral
to the tibial axis.
- Patella alta may be noted.
Classification
Watson-Jones
|
Small fragment avulsed and displaced proximally;
fracture through secondary ossification center |
|
|
Type II: |
Secondary ossification center already
coalesced with proximal tibial epiphysis; fracture at level of horizontal
portion of tibial physis |
|
Type III: |
Fracture line passing proximally through tibial
epiphysis and into joint; possibly confused with Salter-Harris Type III
tibial physeal injury |
This modification of the Watson-Jones
classification (see earlier) subdivides each type into A and B categories to
account for the degree of displacement and comminution (Fig. 11).
|
|
|
Figure 11. (From |
Treatment
Nonoperative
- Indicated
for
- It consists of manual reduction and immobilization in a long leg
cast with the knee extended, with patellar molding.
- The
cast is worn for 4 to 6 weeks, at which time the patient may be placed in
a posterior splint for an additional 2 weeks. Gentle active
range-of-motion exercises and quadriceps strengthening exercises are
instituted and advanced as symptoms abate.
Operative
- Indicated
for Types IB, II, III fractures or irreducible
- A
vertical midline approach is used; the fracture can be stabilized using
smooth pins (>3 years from skeletal maturity), screws, threaded
Steinmann pins, or a tension band.
- Postoperatively,
the extremity is placed in a long leg cast in extension with patella
molding for 4 to 6 weeks, at which time the patient may be placed in a
posterior splint for an additional 2 weeks. Gentle active range-of-motion
exercises and quadriceps strengthening exercises are instituted and advanced
as symptoms abate.
Complications
- Genu recurvatum: This occurs secondary to
premature closure of anterior physis; it is rare because injury occurs
typically in adolescent patients near skeletal maturity.
- Loss of knee motion: Loss of
flexion may be related to scarring or postoperative immobilization. Loss
of extension may be related to nonanatomic reduction and emphasizes the
need for operative fixation of Type IB, II, and III fractures.
- Patella alta: May occur if reduction is
insufficient.
- Osteonecrosis of fracture fragment: Rare
because of soft tissue attachments.
- Compartment syndrome: Rare, but it may
occur with concomitant tearing of the anterior tibial recurrent vessels
that retract to the anterior compartment when torn.
TIBIAL SPINE (INTERCONDYLAR EMINENCE)
FRACTURES
Epidemiology
- Relatively rare injury, occurring in 3 per
100,000 children per year.
- Most commonly caused by a fall from a
bicycle (50%).
Anatomy
- There are two tibial spines: anterior and
posterior. The ACL spans the medial aspect of the lateral femoral condyle
to the anterior tibial spine.
- In the immature skeleton, ligaments are
more resistant to tensile stresses than are physeal cartilage or
cancellous bone; therefore, forces that would lead to an ACL tear in an
adult cause avulsion of the incompletely ossified tibial spine in a child.
Mechanism of Injury
- Indirect
trauma: The mechanism includes rotatory, hyperextension, and valgus
forces.
- Direct
trauma: Extremely rare, secondary to multiple trauma with significant knee
injury.
Clinical Evaluation
- Patients
are typically reluctant to bear weight on the affected extremity.
- Hemarthrosis
is usually present, with painful range of motion and a variable bony block
to full extension.
- The
MCL and lateral collateral ligament (LCL) should be stressed with
varus/valgus pressure to rule out associated injury.
Radiographic Evaluation
- AP and lateral views should be obtained.
The AP view should be scrutinized for osseous fragments within the
tibiofemoral articulation; these may be difficult to appreciate because
only a thin, ossified sleeve may be avulsed.
- Obtaining an AP radiograph to account for
the 5 degrees of posterior slope of the proximal tibia may aid in
visualization of an avulsed fragment.
- Stress views may be useful in
identification of associated ligamentous or physeal disruptions.
Meyers and McKeever (Fig. 12)
|
Minimal or no displacement of fragment |
|
|
Type II: |
Angular elevation of anterior portion with
intact posterior hinge |
|
Type III: |
Complete displacement with or without rotation
(15%) |
|
Type IV: |
Comminuted
(5%) |
|
Types I
and II account for 80% of tibial spine fractures. |
|
|
|
|
Figure 12. Classification of tibial spine fractures. (A) Type I, minimal
displacement. (B) Type II, hinged posteriorly. (C) Type III, complete
separation. (From Bucholz RW, Heckman JD, Court-Brown C, et al., eds. Rockwood and Green’s Fractures in Adults, 6th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.) |
Treatment
Nonoperative
- Indicated
for Type I and II fractures of the tibial spine.
- The
knee should be immobilized in extension; the fat pad may contact the spine
in extension and thus help with reduction.
- After
4 to 6 weeks, the cast is removed with initiation of
active range-of-motion and quadriceps and hamstrings strengthening.
Operative
- Indicated
for Type III and IV fractures of the tibial spine owing to uniformly poor
results with nonoperative management.
- Debridement
of fracture site is recommended with fixation using sutures, pins, or
screws.
- The
fracture may be repaired arthroscopically with an ACL guide.
- Postoperatively,
the patient is placed in a long leg cast with the knee in slight (10 to 20
degree) flexion. In 4 to 6 weeks, the cast is removed with initiation of
active range-of-motion and quadriceps and hamstrings strengthening.
Complications
- Loss of extension: Present in up to 60% of
cases. Extension loss is typically clinically insignificant and may
represent a bony block to extension caused by malunion of a type III
fracture.
- Knee instability: May persist with Type
III or IV fractures accompanied by collateral ligament injuries and/or
physeal fractures.
PATELLA FRACTURES
Epidemiology
- Very rare in children; only 1% of all
patella fractures are seen in patients less than 16 years of age.
Anatomy
- The patella is the largest sesamoid in the
body.
- The function of the patella is to increase
the mechanical advantage and leverage of the quadriceps tendon, aid in
nourishment of the femoral articular surface, and protect the femoral
condyles from direct trauma.
- Forces generated by the quadriceps in
children are not as high as in adults owing to a smaller muscle mass and
shorter moment arm.
- The blood supply to the patella derives
from the anastomotic ring from the superior and inferior geniculate
arteries. An additional supply through the distal pole is from the fat
pad.
- The ossification center appears between 3
and 5 years. Ossification then proceeds peripherally and is complete by 10
to 13 years.
- Patella fracture must be differentiated
from a bipartite patella (present in up to 8% of patients), which is
located superolaterally. One should obtain contralateral films because
bilateral bipartite patella is present in up to 50% of cases.
Mechanism of Injury
- Direct:
Most common and involves trauma to the patella secondary to a fall or
motor vehicle accident. Cartilage anlage acts as a cushion to a direct
blow.
- Indirect:
A sudden accelerating or decelerating force on the quadriceps.
- Marginal
fracture: Usually medial owing to patellar subluxation or dislocation
laterally.
- Predisposing factors
include:
- Previous
trauma to the knee extensor mechanism.
- Spasticity
or contracture of the extensor mechanism.
Clinical Evaluation
- Patients
typically present with refusal to bear weight on the affected extremity.
- Swelling,
tenderness, and hemarthrosis are usually present, often with limited or
absent active extension of the knee.
- Patella
alta may be present with avulsion or sleeve fractures, and a palpable
osseous defect may be appreciated.
- An apprehension test may be positive and may indicate the presence
of a spontaneously reduced patellar dislocation that resulted in a
marginal fracture.
Radiographic Evaluation
- AP, lateral, and patellar (sunrise) views
of the knee should be obtained.
- Transverse fracture patterns are most
often appreciated on lateral view of the knee. The extent of displacement
may be better appreciated on a stress view with the knee flexed to 30
degrees (greater flexion may not be tolerated by the patient).
- Longitudinally oriented and marginal
fractures may be best appreciated on AP or sunrise views. It is important
to distinguish this from osteochondral fracture, which may involve a large
amount of articular surface.
- Stellate fractures and bipartite patella
are best appreciated on AP radiographs. Comparison views of the opposite
patella may aid in delineating a bipartite patella.
Classification
Based on Pattern (Fig.
13)
|
|
|
Figure 13. Patellar fractures in children. (From |
|
Complete
versus incomplete |
|
|
Marginal fractures: |
Generally resulting from lateral subluxation
or dislocation of the patella; may be either medial (avulsion) or lateral
(direct trauma from condyle) |
|
Sleeve fracture: |
Unique to immature skeleton; consisting of an
extensive sleeve of cartilage pulled from the osseous patella with or without
an osseous fragment from the pole |
|
Stellate: |
Generally from direct trauma in the older
child |
|
Longitudinal avulsion |
|
Treatment
Nonoperative
- Indicated
for nondisplaced fractures (<
- Consists of a well-molded cylinder cast with the knee in extension.
- Progressive
weight bearing is permitted as tolerated. The cast is generally
discontinued at 4 to 6 weeks.
Operative
- Displaced
fractures (>
- Sleeve
fracture: Careful reduction of the involved pole and cartilaginous sleeve
is performed with fixation and retinacular repair; if this is missed, the
result is an elongated patella with extensor lag and quadriceps weakness.
- Postoperatively,
the leg is maintained in a well-molded cylinder cast for 4 to 6 weeks. Quadriceps
strengthening and active range-of-motion exercises are instituted as soon
as possible.
- Partial
patellectomy should be reserved for severe comminution.
Complications
- Quadriceps weakness: Compromised
quadriceps function occurs secondary to missed diagnosis or inadequate
treatment with functional elongation of the extensor mechanism and loss of
mechanical advantage.
- Patella alta: Results from functional
elongation of the extensor mechanism and is associated with quadriceps
atrophy and weakness.
- Posttraumatic osteoarthritis: Degenerative
changes occur secondary to chondral damage at the time of injury.
OSTEOCHONDRAL FRACTURES
Epidemiology
- Typically involve the medial or lateral
femoral condyles or the patella.
- Often occur in association with patellar dislocation.
Anatomy
- As the knee flexes, the patella engages
the condylar groove. At 90 to 135 degrees, the patella rides within the
notch.
Mechanism of Injury
- Exogenous:
A direct blow or a shearing force (patellar dislocation). This is the most
common pathologic process.
- Endogenous:
A flexion/rotation injury of the knee. Contact between the tibia and the
femoral condyle results in osteochondral fracture of the condyle.
Clinical Evaluation
- The
patient presents with knee effusion and tenderness over the site of
fracture.
- The
knee is held in a position of comfort, usually in 15 to 20 degrees of
flexion.
- Standard knee AP and lateral x-rays often
establish the diagnosis.
- Schuss and Tunnel views may be helpful to
localize the fragment near the notch.
Treatment
- Operative
excision versus fixation of fragment depends on the size and location of
the defect as well as on the timing of surgery.
- Small
fragments or injuries to non–weight-bearing regions may
be excised either open or arthroscopically.
- Large
fragments may be fixed with subchondral or headless lag screws.
- If
surgery is delayed more than 10 days after the injury, the piece should be
excised because the cartilage is not typically viable.
- Postoperatively,
in patients with internal fixation, a long leg cast with 30 degrees of
flexion is applied. The patient is typically non–weight bearing for 6
weeks.
- If
excision is performed, the patient may bear weight as tolerated and range
the knee after soft tissues heal.
PATELLA DISLOCATION
Epidemiology
- Patella dislocation is more common in
women, owing to physiologic laxity, as well as in patients with
hypermobility and connective tissue disorders (e.g., Ehlers-Danlos or
Marfan syndrome).
Anatomy
- The “Q angle†is defined as the angle subtended by a line drawn from the anterior superior iliac spine through the center of the patella and a second line from the center of the patella to the tibial tubercle (Fig. 14). The Q angle ensures that the resultant vector of pull with quadriceps action is laterally directed; this lateral moment is normally counterbalanced by patellofemoral, patellotibial, and retinacular structures as well as patellar engagement within the trochlear groove. An increased Q angle predisposes to patella dislocation.
- Dislocations are associated with patella
alta, congenital abnormalities of the patella and trochlea, hypoplasia of
the vastus medialis, and hypertrophic lateral retinaculum.
|
|
|
Figure 14. The Q (quadriceps) angle is measured from the anterior superior
iliac spine through the patella and to the tibial tubercle. (From Insall JN. Surgery of the Knee. New York: Churchill Livingstone, 1984.) |
Mechanism of Injury
- Lateral
dislocation: The mechanism is forced internal rotation of the femur on an
externally rotated and planted tibia with the knee in flexion. It is associated
with a 5% risk of osteochondral fractures.
- Medial
instability is rare and usually iatrogenic, congenital, traumatic, or
associated with atrophy of the quadriceps musculature.
- Intraarticular
dislocation: Uncommon, but it may occur following knee trauma in
adolescent boys. The patella is avulsed from the quadriceps tendon and is
rotated around the horizontal axis, with the proximal pole lodged in the
intercondylar notch.
Clinical Evaluation
- Patients
with an unreduced patella dislocation will present with hemarthrosis, an
inability to flex the knee, and a displaced patella on palpation.
- Patients
with a lateral dislocation may also present with medial retinacular pain.
- Patients
with reduced or chronic patella dislocation may demonstrate a positive “apprehension test,†in which a laterally
directed force applied to the patella with the knee in extension
reproduces the sensation of impending dislocation, causing pain and
quadriceps contraction to limit patellar mobility.
Radiographic Evaluation
- AP and lateral views of the knee should be
obtained. In addition, an axial (sunrise) view of both patellae should be
obtained. Various axial views have been described by several authors (Fig. 15)
|
|
|
Figure 15. Representation of the (A) Hughston (knee flexed to 55 degrees) (B)
merchant (knee flexed to 45 degrees) and (C) Laurin (knee flexed to 20
degrees) patellofemoral views. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
- Hughston 55 degrees of knee flexion:
sulcus angle, patellar index
- Merchant 45 degrees of knee flexion:
sulcus angle, congruence angle
- Laurin 20 degrees of knee flexion:
patellofemoral index, lateral patellofemoral angle
- Assessment of patella alta or baja is
based on the lateral radiograph of the knee.
- Blumensaat line: The lower pole of the
patella should lie on a line projected anteriorly from the intercondylar
notch on the lateral radiograph with the patient’s knee flexed to 30 degrees.
- Insall-Salvati ratio: The
ratio of the length of the patellar ligament (LL; from the inferior pole
of the patella to the tibial tubercle) to the patellar length (LP; the
greatest diagonal length of the patella) should be 1.0. A ratio of 1.2
indicates patella alta, whereas 0.8 indicates patella baja (Fig. 16).
|
Figure 16. Insall-Salvati technique for measuring patellar height. (From |
Classification
- Reduced versus unreduced
- Congenital versus acquired
- Acute
(traumatic) versus chronic (recurrent)
- Lateral, medial,
intraarticular, superior
Treatment
Nonoperative
- Reduction
and casting or bracing in knee extension may be undertaken with or without
arthrocentesis for comfort.
- The
patient may ambulate in locked extension for 3 weeks, at which time
progressive flexion can be instituted with physical therapy for quadriceps
strengthening. After a total of 6 to 8 weeks, the patient may be weaned
from the brace.
- Surgical
intervention for acute dislocations is rarely indicated except for
displaced intraarticular fractures.
- Intraarticular
dislocations may require reduction with patient under anesthesia.
- Functional
taping with moderate success has been described in the physical therapy
literature.
Operative
- Primarily
used in cases of recurrent dislocations.
- No
single procedure corrects all patella malalignment problems—the patient’s age, diagnosis, level of
activity, and condition of the patellofemoral articulation must be taken
into consideration.
- Patellofemoral
instability should be addressed by correction of all malalignment factors.
- Degenerative
articular changes influence the selection of realignment procedure.
- Surgical interventions
include:
- Lateral
release: Indicated for patellofemoral pain with lateral tilt, lateral
retinacular pain with lateral patellar position, and lateral patellar
compression syndrome. It may be performed arthroscopically or as an open
procedure.
- Medial
plication: May be performed at the time of lateral release to centralize
the patella.
- Proximal
patellar realignment: Medialization of the proximal pull of the patella
is indicated when a lateral release/medial plication
fails to centralize the patella. The release of tight proximal lateral
structures and reinforcement of the pull of medial supporting structures,
especially the vastus medialis obliquus, are performed in an effort to
decrease lateral patellar tracking and improve congruence of the
patellofemoral articulation. Indications include recurrent patella
dislocations after failed nonoperative therapy and acute dislocations in
young, athletic patients, especially with medial patella avulsion
fractures or radiographic lateral subluxation/tilt after closed
reduction.
- Distal
patella realignment: Reorientation of the patella ligament and the tibial
tubercle is indicated when an adult patient experiences recurrent
dislocations and patellofemoral pain with malalignment of the extensor
mechanism. This is contraindicated in patients with open physes and
normal Q angles. It is designed to advance and medialize tibial tubercle,
thus correcting patella alta and normalizing the Q angle.
Complications
- Redislocation: A younger age at initial dislocation increases the risk of recurrent dislocation. Recurrent dislocation is an indication for surgical intervention.
- Loss of knee motion: May result from
prolonged immobilization.
- Patellofemoral pain: May result from
retinacular disruption at the time of dislocation or from chondral injury.
KNEE DISLOCATION
Epidemiology
- Infrequent in skeletally immature
individuals, because physeal injuries to the distal femur or proximal
tibia are more likely to result.
Anatomy
- Typically occurs with major ligamentous
disruptions (both cruciates or equivalent spine injuries with disruption
of either MCL or/and LCL) about the knee.
- Associated with major disruption of soft
tissue and damage to neurovascular structures; vascular repair must take
place within the first 6 to 8 hours to avoid permanent damage.
- Associated with other knee injuries,
including tibial spine fractures, osteochondral injuries, and meniscal
tears.
Mechanism of Injury
- Most
dislocations occur as a result of multiple trauma from motor vehicle
accidents or falls from a height.
Clinical Evaluation
- Patients
almost always present with gross knee distortion. Immediate reduction
should be undertaken without waiting for radiographs in the displaced
position. Of paramount importance is the arterial supply, with secondary
consideration given to neurologic status.
- The
extent of ligamentous injury is related to the degree of displacement,
with injury occurring with displacement greater than 10%
to 25% of the resting length of the ligament. Gross instability may be
appreciated after reduction.
- A
careful neurovascular examination is critical both before and after
reduction. The popliteal artery is at risk during traumatic dislocation of
the knee owing to the bowstring effect across the popliteal fossa
secondary to proximal and distal tethering. Peroneal nerve injuries are
also common, mostly in the form of traction neurapraxias.
Radiographic Evaluation
- Gross dislocation should be reduced first
and not delayed for films.
- AP and lateral views are sufficient to
establish the diagnosis; the most common direction is anterior.
- Radiographs should be scrutinized for
associated injuries to the tibial spine, distal femoral physis, or
proximal tibial physis. Stress views may be obtained to detect collateral
ligament injury.
- It remains controversial whether all
patients should have an arteriogram. Some authors state that if pulses are
present both before and after reduction, arteriography is not indicated.
The patient must be monitored for 48 to 72 hours after reduction because
late thrombus may develop as a result of intimal damage.
Classification
Descriptive
Based on
displacement of the proximal tibia in relation to the distal femur. It also
should include open versus closed and reducible versus irreducible. The injury
may be classified as occult, indicating a knee dislocation with spontaneous
reduction.
|
Forceful knee hyperextension beyond 30
degrees; most common; associated with PCL with or without ACL tear, with
increasing incidence of popliteal artery disruption with increasing degree of
hyperextension |
|
|
Posterior: |
Posteriorly directed force against proximal
tibia of flexed knee; “dashboardâ€
injury; accompanied by ACL/PCL disruption as well as popliteal artery
compromise with increasing proximal tibial displacement |
|
Lateral: |
Valgus force; medial supporting structures
disrupted, often with tears of both cruciate ligaments |
|
Medial: |
Varus force; lateral and posterolateral
structures disrupted |
|
Rotational: |
Varus/valgus with rotatory component; usually
result in buttonholing of femoral condyle through capsule |
Treatment
- Treatment
is based on prompt recognition and reduction of the knee dislocation, with
recognition of vascular injury and operative intervention if necessary.
- No large series have been reported, but early ligamentous repair is
indicated for young patients.
Complications
- Vascular compromise: Unrecognized and
untreated vascular compromise to the leg, usually in the form of an
unrecognized intimal injury with late thrombosis and ischemia, represents
the most serious and potentially devastating complication from a knee
dislocation. Careful, serial evaluation of neurovascular status is
essential, up to 48 to 72 hours after injury, with aggressive use of
arteriography as indicated.
- Peroneal nerve injury: Usually represents
a traction neurapraxia that will resolve. Electromyography may be
indicated if resolution does not occur within 3 to 6 months.
Pediatric Tibia and Fibula
EPIDEMIOLOGY
- Tibia fractures represent the third most
common pediatric long bone fracture, after femur and forearm fractures.
- They represent 15% of pediatric fractures.
- The average age of occurrence is 8 years
of age.
- Of these fractures, 30% are associated
with ipsilateral fibular fractures.
- Ratio of incidence in boys and girls is
2:1.
- The tibia is the second most commonly
fractured bone in abused children; 26% of abused children with fractures
have a tibia fracture.
ANATOMY
- The anteromedial aspect of the tibia is
subcutaneous, with no overlying musculature for protection.
- Three consistent ossification centers form
the tibia:
- Diaphyseal: Ossifies at 7 weeks of
gestation.
- Proximal epiphysis: The ossification center
appears just after birth, with closure at age 16 years.
- Distal epiphysis: The ossification center
appears in second year, with closure at age 15 years.
- The medial malleolus and tibial tubercle
may present as separate ossification centers and should not be confused
with fracture.
- Fibular ossification centers:
- Diaphyseal: Ossifies at 8 weeks of
gestation.
- Distal epiphysis: The ossification center
appears at age 2 years, with closure at age 16 years.
- Proximal epiphysis: The ossification
center appears at age 4 years, with closure at age 16 to 18 years.
MECHANISM OF INJURY
- Of
pediatric ipsilateral tibia and fibula fractures, 50% result from motor
vehicle trauma.
- Of
tibia fractures with an intact fibula, 81% are caused by indirect
rotational forces.
- Children
ages 1 to 4 years old are susceptible to bicycle spoke trauma, whereas
children 4 to 14 years old most often sustain tibia fractures during
athletic or motor vehicle accidents.
- Isolated
fibula fractures are usually the result of a direct blow.
CLINICAL EVALUATION
- Full
pediatric trauma protocol must be observed because >60% of tibial
fractures are associated with motor vehicle or pedestrian-motor vehicle
trauma.
- Patients
typically present with the inability to bear weight on the injured lower
extremity, as well as pain, variable gross deformity, and painful range of
motion of the knee or ankle.
- Neurovascular evaluation is essential, with assessment of both the
dorsalis pedis and posterior tibial artery pulses.
- Palpation
of the anterior, lateral, and posterior (deep and superficial) muscle
compartments should be performed to evaluate possible compartment
syndrome. When suspected, compartment pressure measurement should be
undertaken, with emergent fasciotomies performed in the case of
compartment syndrome.
- Field
dressings/splints should be removed with exposure of the entire leg to
assess soft tissue compromise and to rule out open fracture.
RADIOGRAPHIC EVALUATION
- Anteroposterior (AP) and lateral views of
the tibia and knee should be obtained. AP, lateral, and mortise views of
the ankle should be obtained to rule out concomitant ankle injury
- Comparison radiographs of the uninjured
contralateral extremity are rarely necessary.
- Technetium bone scan or MRI may be
obtained to rule out occult fracture in the appropriate clinical setting.
PROXIMAL TIBIAL METAPHYSEAL FRACTURES
Epidemiology
- Uncommon, representing <5% of pediatric
fractures and 11% of pediatric tibia fractures.
- Peak incidence is at 3 to 6 years.
Anatomy
- The proximal tibial physis is generally
structurally weaker than the metaphyseal region; this accounts for the
lower incidence of fractures in the tibial metaphysis.
Mechanism of Injury
- Most
common is force applied to lateral aspect of the extended knee that causes
the cortex of the medial metaphysis to fail in tension, usually as
nondisplaced greenstick fractures of the medial cortex.
- The
fibula usually does not fracture, although plastic deformation may occur.
Clinical Evaluation
- The
patient typically presents with pain, swelling, and tenderness in the region
of the fracture.
- Motion
of the knee is painful, and the child usually refuses to ambulate.
- Valgus
deformity is typically present.
Radiographic Evaluation
- AP and lateral views of the tibia should
be obtained, as well as appropriate views of the knee and ankle to rule
out associated injuries.
Descriptive
- Angulation
- Displacement
- Open versus closed
- Pattern:
transverse, oblique, spiral, greenstick, plastic deformation, torus
- Comminution
Treatment
Nonoperative
- Nondisplaced
fractures may be treated in a long leg cast with the knee in near full
extension and with a varus mold.
- Displaced
fractures should undergo closed reduction with the patient under general
anesthesia, with application of a long leg cast with the knee in full
extension and varus moment placed on the cast to prevent valgus collapse.
- The
cast should be maintained for 6 to 8 weeks with frequent radiographic
evaluation to rule out displacement.
- Normal
activities may be resumed when normal knee and ankle motions are restored
and the fracture site is nontender.
Operative
- Fractures
that cannot be reduced by closed means should undergo open reduction with
removal of interposed soft tissue.
- The
pes anserinus insertion should be repaired if torn, with restoration of
tension.
- A
long leg cast with the knee in full extension should be placed and
maintained for 6 to 8 weeks postoperatively with serial radiographs to
monitor healing.
- Open
fractures or grossly contaminated fractures with associated vascular
compromise may be treated with debridement of compromised tissues and
external fixation, particularly in older children. Regional or free flap
or skin grafting may be required for skin closure.
Complications
- Progressive valgus angulation: May result
from a combination of factors, including disruption of the lateral physis
at the time of injury, exuberant medial callus formation that results in
fracture overgrowth, entrapment of periosteum at the medial fracture site
with consequent stimulation of the physis, or concomitant pes anserinus
injury that results in a loss of inhibitory tethering effect on the
physis, allowing overgrowth. The deformity is most prominent within 1 year
of fracture; younger patients may experience spontaneous correction with
remodeling, although older patients may require hemiepiphysiodesis or
corrective osteotomy.
- Premature proximal tibial physeal closure:
May occur with unrecognized crush injury (Salter V) to the proximal tibial
physis, resulting in growth arrest. This most commonly affects the
anterior physis and leads to a recurvatum deformity of the affected knee.
DIAPHYSEAL FRACTURES OF THE TIBIA AND
FIBULA
Epidemiology
- Of pediatric tibial fractures, 39% occur
in the middle third.
- Approximately 30% of pediatric diaphyseal
fractures are associated with a fracture of the fibula. Occasionally, this
is in the form of plastic deformation, producing valgus alignment of the
tibia.
- Isolated fractures of the fibular shaft
are rare and result from direct trauma to the lateral aspect of the leg.
Anatomy
- The nutrient artery arises from the
posterior tibial artery, entering the posterolateral cortex distal to the
origination of the soleus muscle, at the oblique line of the tibia. Once
the vessel enters the intramedullary canal, it gives off three ascending
branches and one descending branch. These give rise to the endosteal
vascular tree, which anastomoses with periosteal vessels arising from the
anterior tibial artery.
- The anterior tibial artery is particularly
vulnerable to injury as it passes through a hiatus in the interosseus membrane.
- The peroneal artery has an anterior
communicating branch to the dorsalis pedis artery.
- The fibula is responsible for 6% to 17% of
weight-bearing load. The common peroneal nerve courses around the neck of
the fibula, which is nearly subcutaneous in this region; it is therefore
especially vulnerable to direct blows or traction injuries at this level.
Mechanism of Injury
- Direct:
Trauma to the leg occurs, mostly in the form of vehicular trauma or
pedestrian-motor vehicle accident.
- Indirect:
In younger children, most tibial fractures result from torsional forces.
These spiral and oblique fractures occur as the body mass rotates on a
planted foot. The fibula prevents significant shortening when intact, but
the fracture frequently falls into varus.
Clinical Evaluation
- The patient typically presents with pain,
swelling, and tenderness in the region of the fracture.
- Motion of the knee is painful, and the
child usually refuses to ambulate.
- Children with stress fractures of the
tibia may complain of pain on weight bearing that is partially relieved by
rest.
Radiographic Evaluation
- Standard AP and lateral views of the leg
should be obtained.
- Radiographs of the ipsilateral ankle and
knee should be obtained to rule out associated injuries.
- Comparison views of the uninjured,
contralateral leg may be obtained in cases in which the diagnosis is
unclear.
- Technetium bone scan or MRI may be
obtained to rule out occult fracture.
Descriptive
- Angulation
- Displacement
- Open versus closed
- Pattern:
transverse, oblique, spiral, greenstick, plastic deformation, torus
- Comminution
Treatment
Nonoperative
- Most
pediatric fractures of the tibia and fibula are uncomplicated and may be
treated by simple manipulation and casting, especially when they are
nondisplaced or minimally displaced. However, isolated tibial diaphyseal
fractures tend to fall into varus, whereas fractures of the tibia and
fibula tend to fall into valgus with shortening and recurvatum (Fig. 17).
|
|
|
Figure 17. The muscles in the anterior and the lateral compartments of the
lower leg produce a valgus deformity in complete ipsilateral tibia and fibula
fractures. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
- Displaced fractures may be initially treated with closed reduction
and casting with the patient under general anesthesia.
- In
children, acceptable reduction includes 50% apposition of the fracture
ends, <
- A
long leg cast is applied with the ankle slightly plantar flexed (20
degrees for distal and middle third fractures, 10 degrees for proximal
third fractures) to prevent posterior angulation of the fracture in the
initial 2 to 3 weeks. The knee is flexed to 45 degrees to provide
rotational control and to prevent weight bearing.
- Fracture
alignment must be carefully monitored, particularly during the initial 3
weeks when atrophy and diminished swelling may result in loss of
reduction. Some patients require repeat manipulation and cast application
under general anesthesia 2 to 3 weeks after initial casting.
- The
cast may require wedging (opening or closing wedge) to provide correction
of angulatory deformity.
- Time
to healing varies according to patient age:
- Neonates: 2 to 3 weeks
- Children: 4 to 6 weeks
- Adolescents: 8 to 12
weeks
Operative
- Operative
management of tibial fractures in children are typically required in
<5% of cases.
- Indications
for operative management include:
- Open fracture.
- Fractures
in which a stable reduction is unable to be achieved or maintained.
- Associated vascular
injury.
- Fractures
associated with compartment syndrome.
- Severely comminuted
fractures.
- Associated
femoral fracture (floating knee).
- Fractures
in patients with spasticity syndromes (cerebral palsy, head injury).
- Patients
with bleeding diatheses (hemophilia).
- Patients with multisystem
injuries.
- Open
fractures or grossly contaminated fractures with associated vascular
compromise may be treated with debridement of compromised tissues and
external fixation, particularly in older children. Severe degloving
injuries may require the use of flexible, intramedullary nails for fracture
stabilization. Regional or free flaps or skin grafting may be required for
skin closure.
- Other
methods of operative fixation include percutaneous pins, plates and
screws, flexible intramedullary nails or rigid intramedullary nails (in
adolescents after closure of the proximal tibia physis).
- Postoperatively,
a long leg cast is usually placed (depending on the method of fixation),
with the knee in 45 degrees of flexion to allow for rotational control.
The cast is maintained for 4 to 16 weeks depending on the status of
healing, as evidenced by serial radiographs, as well as the healing of
associated injuries.
- Compartment syndrome: In pediatric tibia
fractures, compartment syndrome is most common after severe injury in
which the interosseous membrane surrounding the anterior compartment is
disrupted. Patients with elevated compartment pressures >
- Angular deformity: Correction of deformity
varies by age and gender.
- Girls <8 years old and boys <10
years old often experience significant remodeling.
- Girls 9 to 12 years old and boys 11 to 12
years old can correct up to 50% of angulation.
- In children >13 years, <25% angular
correction is expected.
- Posterior and valgus angulation tends to
correct the least with remodeling.
- Malrotation: Rotational deformity of the tibia does not correct with remodeling and is poorly tolerated, often resulting in malpositioning of the foot with the development of associated ankle and foot problems. Supramalleolar osteotomy may be required for rotational correction.
- Premature proximal tibial physeal closure:
This may occur with unrecognized crush injury (Salter Type V) to the
proximal tibial physis, resulting in growth arrest. This most commonly
affects the anterior physis and leads to a recurvatum deformity of the
affected knee.
- Delayed union and nonunion: Uncommon in
children, but it may occur as a result of infection, the use of external
fixation, or inadequate immobilization. Fibulectomy, bone grafting, reamed
intramedullary nailing (adolescents), and plate fixation with bone
grafting have all been described as methods to treat tibial nonunions in the
pediatric population.
FRACTURES OF THE DISTAL TIBIAL
METAPHYSIS
Epidemiology
- Fractures of the distal third of the tibia
comprise approximately 50% of pediatric tibia fractures.
- Most occur in patients younger than 14
years, with the peak range of incidence in children between ages 2 and 8
years.
Anatomy
- Distally, the tibia flares out as the
cortical diaphyseal bone changes to cancellous metaphyseal bone overlying
the articular surface. This is similar to the tibial plateau in that there
is primarily cancellous bone within a thin cortical shell.
Mechanism of Injury
- Indirect:
An axial load results from a jump or fall from a height.
- Direct:
Trauma to the lower leg occurs, such as in bicycle spoke injuries in which
a child’s foot is thrust forcibly between the spokes of a turning bicycle
wheel, resulting in severe crush to the distal leg, ankle, and foot with
variable soft tissue injury.
- Patients
typically are unable to ambulate or are ambulatory only with severe pain.
- Although
swelling may be present with variable abrasions or lacerations, the foot,
ankle, and leg typically appear relatively normal without gross deformity.
- The
entire foot, ankle, and leg should be exposed to evaluate the extent of
soft tissue injury and to assess for possible open fracture.
- A
careful neurovascular examination is important, and the presence of
compartment syndrome must be excluded.
- In
cases of bicycle spoke injuries, palpation of all bony structures of the
foot and ankle should be performed as well as assessment of ligamentous
integrity and stability.
Radiographic Evaluation
- AP and lateral views of the leg should be
obtained. Appropriate views of the ankle and knee should be taken to rule
out associated injuries, as well as views of the foot as indicated.
- Fractures of the distal metaphysis
typically represent greenstick injuries, with anterior cortical impaction,
posterior cortical disruption, and tearing of the overlying periosteum,
often resulting in a recurvatum pattern of injury.
- In severe torsional injuries with
impaction or distraction forces, a spiral fracture may result.
- Computed tomography is usually
unnecessary, but it may aid in fracture definition in comminuted or
complex fractures.
Classification
Descriptive
- Angulation
- Displacement
- Open versus closed
- Pattern:
transverse, oblique, spiral, greenstick, plastic deformation, torus
- Comminution
- Associated injuries: knee,
ankle, foot
Treatment
Nonoperative
- Nondisplaced,
minimally displaced, torus, or greenstick fractures should be treated with
manipulation and placement of a long leg cast.
- In
cases of recurvatum deformity of the tibial fracture, the foot should be
placed in plantar flexion to prevent angulation into recurvatum.
- After
3 to 4 weeks of plaster immobilization, if the fracture demonstrates
radiographic evidence of healing, the long leg cast is discontinued and is
changed to a short leg walking cast with the ankle in the neutral
position.
- A
child with a bicycle spoke injury should be admitted as an inpatient for
observation, because the extent of soft tissue compromise may not be
initially evident.
- A long leg splint should be applied with the lower extremity
elevated for 24 hours, with serial examination of the soft tissue
envelope over the ensuing 48 hours.
- If
no open fracture exists and soft tissue compromise is minimal, a long leg
cast may be placed before discharge, with immobilization as described
previously.
Operative
- Surgical
intervention is warranted for cases of open fracture or when stable
reduction is not possible by closed means.
- Unstable
distal tibial fractures can typically be managed with closed reduction and
percutaneous pinning using Steinmann pins or Kirschner wire fixation.
Rarely, a comminuted fracture may require open reduction and internal
fixation using pins or plates and screws.
- Postoperatively,
the patient is immobilized in a long leg cast. The fracture should be
monitored with serial radiographs to assess healing. At 3 to 4 weeks, the
pins may be removed with replacement of the cast either with a long leg
cast or a short leg walking cast, based on the extent of healing.
- Open
fractures may require external fixation to allow for wound management.
Devitalized tissue should be débrided as necrosis becomes
apparent. Aspiration of large hematomas should be undertaken to avoid
compromise of overlying skin. Skin grafts or flaps (regional or free) may
be necessary for wound closure.
Complications
- Recurvatum: Inadequate reduction or fracture
subsidence may result in a recurvatum deformity at the fracture. Younger
patients tend to tolerate this better, because remodeling typically
renders the deformity clinically insignificant. Older patients may require
supramalleolar osteotomy for severe recurvatum deformity that compromises
ankle function and gait.
- Premature distal tibial physeal closure:
May occur with unrecognized crush injury (Salter Type V) to the distal
tibial physis, resulting in growth arrest.
TODDLER'S FRACTURE
Epidemiology
- A toddler’s fracture is by definition a
spiral fracture of the tibia in the appropriate age group.
- Most of these fractures occur in children
younger than 2.5 years.
- The average age of incidence is 27 months.
- This tends to occur in boys more often
than in girls and in the right leg more frequently than the left.
Anatomy
- The distal epiphysis appears at
approximately 2 years of age; thus, physeal injuries of the distal tibia
may not be readily apparent and must be suspected.
Mechanism of Injury
- The
classic description of the mechanism of a toddler’s
fracture is external rotation of the foot with the knee in fixed position,
producing a spiral fracture of the tibia with or without concomitant
fibular fracture.
- This
injury has also been reported as a result of a fall.
Clinical Evaluation
- Patients
typically present irritable and nonambulatory or with an acute limp.
- The
examination of a child refusing to ambulate without readily identifiable
causes should include a careful history, with attention to temporal
progression of symptoms and signs (e.g., fever), as well as a systematic
evaluation of the hip, thigh, knee, leg, ankle, and foot, with attention
to points of tenderness, swelling, or ecchymosis. This should be followed
by radiographic evaluation as well as appropriate laboratory analysis if
the diagnosis remains in doubt.
- In
the case of a toddler’s fracture, pain and
swelling are variable on palpation of the tibia. These features are
usually appreciated over the anteromedial aspect of the tibia, where its
subcutaneous nature allows for minimal soft tissue protection.
Radiographic Evaluation
- AP and lateral views of the leg should be
obtained.
- An internal oblique radiograph of the leg
may be helpful for demonstration of a nondisplaced spiral fracture.
- Occasionally, an incomplete fracture may
not be appreciated on presentation radiographs but may become
radiographically evident 7 to 10 days after the injury as periosteal new
bone formation occurs.
- Technetium bone scans may aid in the
diagnosis of toddler’s fracture by visualization of diffusely
increased uptake throughout the tibia. This may be differentiated from
infection, which tends to produce a localized area of increased uptake.
Treatment
- A
long leg cast for 2 to 3 weeks followed by conversion to a short leg
walking cast for an additional 2 to 3 weeks is usually sufficient.
- Manipulation
is generally not necessary because angulation and displacement are usually
minimal and within acceptable limits.
Complications
- Complications of toddler’s
fractures are rare owing to the low-energy nature of the injury, the age
of the patient, and the rapid and complete healing that typically
accompanies this fracture pattern.
- Rotational deformity: Toddler’s
fractures may result in clinically insignificant rotational deformity of
the tibia as the fracture slides minimally along the spiral configuration.
This is usually unnoticed by the patient but may be appreciated on
comparison examination of the lower limbs.
STRESS FRACTURES
Epidemiology
- Most tibia stress fractures occur in the
proximal third.
- The peak incidence of tibia stress
fractures in children is between the ages of 10 and 15 years.
- Most fibula stress fractures occur in the
distal third.
- The peak incidence of fibula stress
fractures in children is between the ages of 2 and 8 years.
- The tibia is more often affected than the
fibula in children; the opposite is true in adults.
Mechanism of Injury
- An
acute fracture occurs when the force applied to a bone exceeds the bone’s capacity to withstand it. A stress fracture occurs when a bone
is subjected to repeated trauma with a strain that is less than what would
have produced an acute fracture.
- With
microtrauma, osteoclastic tunnel formation increases to remodel
microcracks. New bone formation results in the production of immature,
woven bone that lacks the strength of the mature bone it replaced,
predisposing the area to fracture with continued trauma.
- Stress
fractures in older children and adolescents tend to be as a result of
athletic participation.
- Distal
fibula stress fractures have been referred to as the “ice
skater’s fracture,†because of the repeated
skating motion that results in a characteristic fibular fracture
approximately
Clinical Evaluation
- Patients
typically presents with an antalgic gait that is relieved by rest,
although younger patients may refuse to ambulate.
- The
pain is usually described as insidious in onset, worse with activity, and
improved at night.
- Swelling
is generally not present, although the patient may complain of a vague
ache over the site of fracture with tenderness to palpation.
- Knee
and ankle range of motion are usually full and painless.
- Occasionally,
the patient’s symptoms and signs may be bilateral.
- Muscle
sprains, infection, and osteosarcoma must be excluded. Exercise-induced
compartment syndrome overlying the tibia may have a similar clinical
presentation.
Radiographic Evaluation
- AP and lateral views of the leg should be
obtained to rule out acute fracture or other injuries, although stress
fractures are typically not evident on standard radiographs for 10 to 14
days after initial onset of symptoms.
- Radiographic evidence of fracture repair
may be visualized as periosteal new bone formation, endosteal
radiodensity, or the presence of “eggshell†callus at the site of
fracture.
- Technetium bone scan reveals a localized
area of increased tracer uptake at the site of fracture and may be
performed within 1 to 2 days of injury.
- Computed tomography rarely
demonstrates the fracture line, although it may delineate increased marrow
density and endosteal/periosteal new bone formation and soft tissue edema.
- Magnetic resonance imaging may demonstrate
a localized band of very low signal intensity continuous with the cortex.
Classification
- Stress
fractures may be classified as complete versus incomplete or acute versus
chronic or recurrent. They rarely are displaced or angulated.
Treatment
- The
treatment of a child presenting with a tibia or fibula stress fracture
begins with activity modification.
- The
child may be placed in a long leg (tibia) or short leg (fibula) cast,
initially non–weight bearing with a gradual increase in
activity level. The cast should be maintained for 4 to 6 weeks until the
fracture site is nontender and radiographic evidence of healing occurs.
- Nonunion
may be addressed with open excision of the nonunion site with iliac crest
bone grafting or electrical stimulation.
Complications
- Recurrent stress fractures: These may be the result of overzealous training regimens, such as for gymnastics or ice skating. Activity modification must be emphasized to prevent recurrence.
- Nonunion: Rare, occurring most commonly in
the middle third of the tibia.
Pediatric Ankle
EPIDEMIOLOGY
- Ankle injuries account for 25% to 38% of
all physeal injuries, third in frequency following phalangeal and distal
radius physeal injuries.
- Fifty-eight percent of ankle physeal
injuries occur during athletic participation.
- They represent 10% to 40% of all injuries
in skeletally immature athletes.
- Tibial physeal fractures are most common
from 8 to 15 years of age.
- Fibular physeal injuries are most common
from 8 to 14 years of age.
- Ligamentous injuries are rare in children
because their ligaments are stronger relative to the physis.
- After age 15 to 16 years, see adult fracture
pattern.
ANATOMY
- The ankle is a modified hinge joint
stabilized by medial and lateral ligamentous complexes. All ligaments
attach distal to the physes of the tibia and fibula—important in the pathoanatomy
of pediatric ankle fracture patterns.
- The distal tibial ossific nucleus appears
between the ages of 6 and 24 months; it fuses with the tibial shaft at
about age 15 years in girls and 17 years in boys. Over an 18-month period,
the lateral portion of the distal tibial physis remains open while the medial
part has closed.
- The distal fibular ossific nucleus appears
at the age of 9 to 24 months and unites with the fibula shaft 12 to 24
months after tibial physis closure.
- Secondary ossification centers occur and
can be confused with a fracture of either the medial or lateral malleolus;
they are often bilateral.
MECHANISM OF INJURY
- Direct:
Trauma to the ankle from a fall, motor vehicle accident, or
pedestrian-motor vehicle accident.
- Indirect:
Axial force transmission through the forefoot and hindfoot or rotational
force of the body on a planted foot; it may be secondary to a fall or,
more commonly, athletic participation.
CLINICAL EVALUATION
- Patients
with displaced ankle fractures typically present with pain and gross
deformity, as well as an inability to ambulate.
- Physical
examination may demonstrate tenderness, swelling, and ecchymosis.
- Ligamentous
instability may be present, but it is usually difficult to elicit on
presentation owing to pain and swelling from the acute injury.
- Ankle sprains are a diagnosis of exclusion and should be
differentiated from a nondisplaced fracture based on the location of
tenderness.
- Neurovascular
examination is essential, with documentation of dorsalis pedis and
posterior tibial pulses, capillary refill, sensation to light touch and
pinprick, and motor testing.
- Dressings
and splints placed in the field should be removed and soft tissue
conditions assessed, with attention to skin lacerations that may indicate
open fracture or fracture blisters that may compromise wound healing.
- The
ipsilateral foot, leg, and knee should be examined for concomitant injury.
RADIOGRAPHIC EVALUATION
- Anteroposterior (AP), lateral, and mortise
views of the ankle should be obtained. Tenderness of the proximal fibula
warrants appropriate views of the leg.
- Clinical examination will dictate the
possible indication for obtaining views of the knee and foot.
- Stress views of the ankle may be obtained
to determine possible ligamentous instability.
- The presence of secondary ossification
centers (a medial os subtibiale in 20% of patients or a lateral os
subfibulare in 1% of patients) should not be confused with fracture,
although tenderness may indicate injury.
- A Tillaux fragment represents an osseous
fragment from the lateral distal tibia that has been avulsed during
injury.
- Computed tomography (CT) is often helpful
for evaluation of complex intra-articular fractures, such as the juvenile
Tillaux or triplane fracture.
- Magnetic resonance imaging has been used
to delineate osteochondral injuries in association with ankle fractures.
CLASSIFICATION
Dias and Tachdjian
- Lauge-Hansen
principles are followed, incorporating the Salter-Harris classification.
- The
typology is simplified by noting the direction of physeal displacement,
Salter-Harris type, and location of the metaphyseal fragment.
- The
classification aids in determining the proper maneuver for closed
reduction (Fig. 18)
|
|
|
Figure 18. Dias-Tachdjian classification of physeal injuries of the distal
tibia and fibula. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
Supination–External
Rotation (SER)
|
Salter-Harris Type II fracture of the distal
tibia with the metaphyseal fragment located posterolaterally; the distal
fragment is displaced posteriorly, but the Thurston-Holland fragment is seen
on the AP x-ray, which differentiates it from a supination–plantar flexion (SPF) injury. |
|
|
Stage II: |
As external rotation force continues, a
spiral fracture of the fibula occurs beginning medially and extending
posterosuperiorly; it differs from an adult SER injury. |
Pronation–Eversion–External Rotation (PEER)
- This type comprises 15% to 20% of
pediatric ankle fractures.
- Marked valgus deformity occurs.
- Tibial and fibular fractures occur
simultaneously.
- Salter-Harris Type II fracture of the
distal tibial physis is most commonly seen, but Type I also occurs; the
metaphyseal fragment is located laterally.
- The short oblique distal fibular fracture
occurs 4 to
Supination–Plantar
Flexion (SPF)
- Most commonly, this is a Salter-Harris
Type II fracture of the distal tibial physis with the metaphyseal fragment
located posteriorly; Type I Salter-Harris fractures are rare.
- Fibula fracture is rare.
Supination–Inversion (SI)
- This is the most common mechanism of
fracture and has the highest incidence of complications.
|
Salter-Harris Type I or II fracture of the
distal fibular physis is most common because the adduction or supination
force avulses the epiphysis; pain is noted along the physis when x-rays are
negative. This
is the most common pediatric ankle fracture. |
|
|
Stage II: |
Salter-Harris Type III or IV fracture of the
medial tibial physis occurs as the talus wedges into the medial tibial
articular surface; rarely, this is a Type I or II fracture. These are
intraarticular fractures that exhibit the highest rate of growth disturbance
(i.e., physeal bar formation). |
Axial Compression (Fig. 19)
|
|
|
Figure 19. Compression-type injury of the tibial physis. Early physeal arrest
can cause leg length discrepancy. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
- A Salter-Harris Type V injury to the
distal tibia.
- A rare injury with poor prognosis
secondary to physeal growth arrest.
- Diagnosis is often delayed
until premature physeal closure is found with a leg length discrepancy.
Juvenile Tillaux Fractures (Fig.
20)
|
|
|
Figure 20. Juvenille Tillaux fracture. Mechanism of injury, the anteroinferior
tibiofibular ligament avulses a fragment of the lateral epiphysis (A)
corresponding to the portion of the physis that is still open (B). (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
- These are Salter-Harris Type
III fractures of the anterolateral tibial epiphysis; they occurs in 2.9%
of ankle fractures.
- External rotation force causes the
anterior tibiofibular ligament to avulse the fragment.
- These fractures occur in the 13- to
16-year age group when the central and medial portions of the distal
tibial physis have already fused, and the lateral physis remains open (Fig. 21).
- Patients with Tillaux fractures are
generally older than those with triplane fractures.
- CT scans or tomograms are helpful in
distinguishing these injuries from triplane fractures.
|
|
|
Figure 21. Closure of the distal tibial physis begins centrally (A) and extends
medially (B) and then laterally (C) before final closure (D). (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
Triplane Fractures
- Occur in three planes: transverse,
coronal, and sagittal.
- Fractures are explained by fusion of
tibial physis from central to anteromedial to posteromedial and finally to
lateral.
- Peak age incidence is 13 to 15 years in
boys and 12 to 14 years in girls.
- Mechanism is thought to be external
rotation of the foot and ankle.
- Fibula fracture is possible; it is usually
oblique from anteroinferior to posterosuperior 4 to
- CT is valuable in the preoperative
assessment.
- Two- and three-part types have been
described (Figs. 22 and 23):
- Two-part fractures are either medial, in
which the coronal fragment is posteromedial, or lateral, in which the
coronal fragment is posterolateral.
- Three-part fractures consist of (1) an
anterolateral fragment that mimics the Juvenile Tillaux fracture
(Salter-Harris Type III), (2) the remainder of the physis with a
posterolateral spike of the tibial metaphysis, and (3)
the remainder of the distal tibial metaphysis.
|
|
|
Figure 22. Anatomy of a two-part lateral triplane fracture (left ankle). Note
the large posterolateral epiphyseal fragment with its posterior metaphyseal
fragment. The anterior portion of the medial malleolus remains intact. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
|
|
|
Figure 23. Anatomy of a three-part lateral triplane fracture (left ankle). Note
the large epiphyseal fragment with its metaphyseal component and the smaller
anterolateral epiphyseal fragment. (From Bucholz RW, Heckman JD, eds. Rockwood and
Green’s Fractures in
Adults, 5th ed. |
TREATMENT
Lateral
Malleolar (Distal Fibula) Fracture
Salter-Harris
Type I or II
- Closed reduction and casting with a short
leg walking cast for 4 to 6 weeks is recommended.
Salter-Harris
Type III or IV
- Closed reduction and percutaneous pinning
with Kirschner wire fixation is followed by placement of a short leg cast.
- Open reduction may be required
for interposed periosteum, with fixation using an intramedullary Kirschner
wire perpendicular to the physis.
Medial
Malleolar (Distal Tibia) Fracture
Salter-Harris
Type I or II
- Closed reduction is the treatment of
choice; it is usually attainable unless soft tissue interposition prevents
reduction.
- In children <10 years old, some residual
angulation is acceptable, because remodeling occurs.
- Open reduction may be necessary for
interposed periosteum, with placement of a transmetaphyseal compression
screw or Kirschner wire parallel and proximal to the physis.
- A long leg cast for 3 weeks is followed by
a short leg walking cast for 3 weeks.
Salter-Harris
Type III or IV
- Anatomic reduction is essential.
- Intraarticular displacement >
- Open reduction and internal fixation may
be performed through an anteromedial approach with cancellous screw(s)
placed parallel below and/or above the physis.
- Postoperative immobilization consists of
short leg casting for 6 weeks.
- Weekly x-rays should be obtained for the
first several weeks to ensure that the intraarticular fragment does not
displace.
Juvenile Tillaux Fracture
- Closed reduction can be attempted by
gentle distraction accompanied by internal rotation of the foot and direct
pressure over the anterolateral tibia; reduction may be maintained in a
short or long leg cast, depending on the rotational stability. The patient
is non–weight bearing for the initial 3 weeks, followed by a short leg
walking cast for an additional 3 weeks.
- Unstable injuries may require percutaneous
pinning with Kirschner-wire fixation.
- Displacement >
- Open reduction and internal fixation may
be achieved via an anterolateral approach with cancellous screw fixation.
- CT may be used to assess reduction.
Triplane Fracture
- Nondisplaced fractures may be treated in a
long leg cast with the knee flexed to 30 degrees for 3 to 4 weeks,
followed by an additional 3 weeks in a short leg walking cast.
- Articular displacement >
- CT may be used to assess the adequacy of
reduction.
- Postoperative immobilization
consists of a short or long leg cast (depending on stability of fixation)
for 3 to 4 weeks followed by a short leg walking cast for an additional 3
weeks.
COMPLICATIONS
- Angular deformity: May occur secondary to
premature physeal arrest, especially after Salter-Harris Type III and IV
injuries. Harris growth lines may be seen at 6 to 12 weeks after injury as
an indication of growth arrest.
- Varus deformity is most common in SI
injuries with premature arrest of the medial tibial physis.
- Valgus deformity is seen with distal
fibula physeal arrest; it may result from poor reduction or interposed
soft tissue.
- Rotational deformities may occur with
inadequately reduced triplane fractures; extraarticular rotational
deformities may be addressed with derotational osteotomies, but
intraarticular fractures cannot.
- Leg length discrepancy: Complicates up to
10% to 30% of cases and is dependent on the age of the patient.
Discrepancy of 2 to
- Posttraumatic arthritis: may occur as a
result of inadequate reduction of the articular surface in Salter-Harris
Type III and IV fractures.
Pediatric Foot
TALUS
Epidemiology
- Extremely rare in children (0.01% to 0.08%
of all pediatric fractures).
- Most represent fractures through the talar
neck.
Anatomy
- The ossification center of the talus
appears at 8 months in utero (Fig. 24).
|
|
|
Figure 24. Time of appearance and fusion of ossification centers of the foot.
Figures in parentheses indicate the time of fusion of primary and secondary
ossification centers (y., years; m.i.u, months in utero). (Redrawn from Aitken JT, Joseph J, Causey G, et al. A Manual of Human Anatomy, 2nd ed, vol. IV. London: E & S Livingstone, 1966:80.) |
- Two thirds of the talus is covered with
articular cartilage.
- The body of the talus is covered
superiorly by the trochlear articular surface through which the body
weight is transmitted. The anterior aspect is wider than the posterior
aspect, which confers intrinsic stability to the ankle.
- Arterial supply to the talus is from two
main sources:
- Artery to the tarsal canal: This arises
from the posterior tibial artery
- Artery of the tarsal sinus: This
originates from the anastomotic loop of the perforating peroneal and
lateral tarsal branches of the dorsalis pedis artery.
- An os trigonum is present in up to 50% of
normal feet. It arises from a separate ossification center just posterior
to the lateral tubercle of the posterior talar process.
Mechanism of Injury
- Forced
dorsiflexion of the ankle from motor vehicle accident or fall represents
the most common mechanism of injury in children. This typically results in
a fracture of the talar neck.
- Isolated
fractures of the talar dome and body have been described but are extremely
rare.
Clinical Evaluation
- Patients
typically present with pain on weight bearing on the affected extremity.
- Ankle
range of motion is typically painful, especially with dorsiflexion, and
may elicit crepitus.
- Diffuse
swelling of the hindfoot may be present, with tenderness to palpation of
the talus and subtalar joint.
- A
neurovascular examination should be performed.
Radiographic Evaluation
- Standard anteroposterior (AP), mortise,
and lateral radiographs of the ankle should be obtained, as well as AP,
lateral, and oblique views of the foot.
- The Canale view provides an
optimum view of the talar neck. With the ankle in maximum equinus, the
foot is placed on a cassette, pronated 15 degrees, and the x-ray tube is
directed cephalad 75 degrees from the horizontal.
- Computed tomographic scanning may be useful
for preoperative planning.
- Magnetic resonance imaging may be used to
identify occult injuries in children <10 years old owing to limited
ossification at this age.
Classification
Descriptive
- Location: most talar fractures in children
occur through the talar neck
- Angulation
- Displacement
- Dislocation: subtalar, talonavicular or
ankle joints
- Pattern: presence of comminution
Hawkins Talar Neck Fractures
This
classification is for adults, but it is often used for children.
|
Nondisplaced |
|
|
Type II: |
Displaced with associated subtalar
subluxation or dislocation |
|
Type III: |
Displaced with associated subtalar and ankle
dislocation |
|
Type IV: |
Type III with associated talonavicular
subluxation or dislocation |
See Chapter 40 for figures.
Treatment
Nonoperative
- Nondisplaced
fractures may be managed in a long leg cast with the knee flexed 30
degrees to prevent weight bearing. This is maintained for 6 to 8 weeks
with serial radiographs to assess healing status. The patient may then be
advanced to weight bearing in a short leg walking cast for an additional 2
to 3 weeks.
Operative
- Indicated
for displaced fractures (defined as >
- Minimally
displaced fractures can often be treated successfully with closed reduction
with plantar flexion of the forefoot as well as hindfoot eversion or
inversion, depending on the displacement.
- A
long leg cast is placed for 6 to 8 weeks; this may require plantar
flexion of the foot to maintain reduction. If the reduction cannot be
maintained by simple positioning, operative fixation is indicated.
- Displaced
fractures are usually amenable to internal fixation using a posterolateral
approach and
- Postoperatively,
the patient is maintained in a short leg cast for 6 to 8 weeks, with
removal of pins at 3 to 4 weeks.
Complications
- Osteonecrosis: may occur with disruption or thrombosis of the tenuous vascular supply to the talus. This is related to the initial degree of displacement and angulation and, theoretically, the time until fracture reduction. It tends to occur within 6 months of injury.
- Hawkins sign represents subchondral
osteopenia in the vascularized, non–weight-bearing talus at 6 to 8
weeks; although this tends to indicate talar viability, the presence of
this sign does not rule out osteonecrosis.
|
Type I fractures: |
0% to 27%
incidence of osteonecrosis reported |
|
Type II fractures: |
42% incidence |
|
Type III, IV fractures: |
>90% incidence |
CALCANEUS
Epidemiology
- A rare injury, typically involving older
children (>9 years) and adolescents.
- Most are extraarticular, involving the
apophysis or tuberosity.
- Of these, 33% are associated with other
injuries, including lumbar vertebral and ipsilateral lower extremity
injuries.
Anatomy
- The primary ossification center appears at
7 months in utero; a secondary ossification center appears at age 10 years
and fuses by age 16 years.
- The calcaneal fracture patterns in children
differ from that of adults, primarily for three reasons:
- The lateral process, which is responsible
for calcaneal impaction resulting in joint depression injury in adults,
is diminutive in the immature calcaneus.
- The posterior facet is parallel to the ground,
rather than inclined as it is in adults.
- In children, the calcaneus is composed of
a ossific nucleus surrounded by cartilage.
These are
responsible for the dissipation of the injurious forces that produce classic
fracture patterns in adults.
Mechanism of Injury
- Most calcaneal fractures occur as a result
of a fall or a jump from a height, although typically a lower-energy
injury occurs than seen with adult fractures.
- Open fractures may result from lawnmower
injuries.
Clinical Evaluation
- Patients
typically are unable to walk secondary to hindfoot pain.
- On
physical examination, pain, swelling, and tenderness can usually be
appreciated at the site of injury.
- Examination
of the ipsilateral lower extremity and lumbar spine is essential, because
associated injuries are common.
- A
careful neurovascular examination should be performed.
- Injury
is initially missed in 44% to 55% of cases.
Radiographic Evaluation
- Dorsoplantar, lateral, axial, and lateral
oblique views should be obtained for evaluation of pediatric calcaneal
fractures.
- The Böhler tuber joint angle: This
is represented by the supplement (180 degree measured angle) of two lines:
a line from the highest point of the anterior process of the calcaneus to
the highest point of the posterior articular surface and a line drawn
between the same point on the posterior articular surface and the most
superior point of the tuberosity. Normally, this angle is between 25 and
40 degrees; flattening of this angle indicates collapse of the posterior
facet (Fig. 25).
|
|
|
Figure 25. The landmarks for measuring the Böhler angle are
the anterior and posterior facets of the calcaneus and the superior border of
the tuberosity. The neutral triangle, largely occupied by blood vessels,
offers few supporting trabeculae directly beneath the lateral process of the
talus. (From Harty MJ. Anatomic considerations in injuries of the calcaneus. Orthop Clin North Am 1973;4:180.) |
- Comparison views of the contralateral foot
may help detect subtle changes in the Böhler angle.
- Technetium bone scanning may be utilized
when calcaneal fracture is suspected but is not appreciated on standard
radiographs.
- Computed tomography may aid in fracture
definition, particularly in intraarticular fractures in which preoperative
planning may be facilitated by three-dimensional characterization of fragments.
Classification
Schmidt and
Weiner (Fig. 26)
|
|
|
Figure 26. Classification used to evaluate calcaneal fracture pattern in
children. (A) Extraarticular fractures. (B) Intraarticular fractures. (C)
Type VI injury with significant bone loss, soft tissue injury, and loss of
insertion of Achilles tendon. (From Schmidt TL, Weiner DS. Calcaneus fractures in children: an evaluation of the nature of injury in 56 children. Clin Orthop 1982;171:150.) |
|
A. Fracture of the tuberosity or apophysis |
|
|
B. Fracture of the sustentaculum |
|
|
C. Fracture of the anterior process |
|
|
D. Fracture of the anterior inferolateral
process |
|
|
E. Avulsion fracture of the body |
|
|
Type II: |
Fracture of the posterior and/or superior
parts of the tuberosity |
|
Type III: |
Fracture of the body not involving the
subtalar joint |
|
Type IV: |
Nondisplaced or minimally displaced fracture
through the subtalar joint |
|
Type V: |
Displaced fracture through the subtalar joint |
|
A.
Tongue type |
|
|
B.
Joint depression type |
|
|
Type VI: |
Either unclassified (Rasmussen and Schantz)
or serious soft tissue injury, bone loss, and loss of the insertions of the
Achilles tendon |
Treatment
Nonoperative
- Cast
immobilization is recommended for pediatric patients with extraarticular
fractures as well as nondisplaced (<
- Mild
degrees of joint incongruity tend to remodel well, although severe joint
depression is an indication for operative management.
Operative
- Operative
treatment is indicated for displaced articular fractures, particularly in
older children and adolescents.
- Displaced
fractures of the anterior process of the calcaneus represent relative
indications for open reduction and internal fixation, because up to 30%
may result in nonunion.
- Anatomic
reconstitution of the articular surface is imperative, with lag screw
technique for operative fixation.
Complications
- Posttraumatic osteoarthritis: This may be
secondary to residual or unrecognized articular incongruity. Although
younger children remodel very well, this emphasizes the need for anatomic
reduction and reconstruction of the articular surface in older children
and adolescents.
- Heel widening: This is not as significant
a problem in children as it is in adults because the mechanisms of injury
tend not to be as high energy (i.e., falls from lower heights with less
explosive impact to the calcaneus) and remodeling can partially restore
architectural integrity.
- Nonunion: This rare complication most
commonly involves displaced anterior process fractures treated
nonoperatively with cast immobilization. This is likely caused by the
attachment of the bifurcate ligament that tends to produce a displacing
force on the anterior fragment with motions of plantar flexion and
inversion of the foot.
- Compartment syndrome: Up to 10% of
patients with calcaneal fractures have elevated hydrostatic pressure in
the foot; half of these patients (5%) will develop claw toes if surgical
compartment release is not performed.
TARSOMETATARSAL (LISFRANC) INJURIES
Epidemiology
- Extremely uncommon in children.
- They tend to occur in older children and
adolescents (>10 years of age).
Anatomy (Fig. 27)
|
|
|
Figure 27. The ligamentous attachments at the tarsometatarsal joints. There is
only a flimsy connection between the bases of the first and second
metatarsals (not illustrated). The second metatarsal is recessed and firmly
anchored. (From Wiley JJ. The mechanism of tarsometatarsal joint injuries. J Bone Joint Surg Br 1971;53:474.) |
- The base of the second metatarsal is the “keystone†of an
arch that is interconnected by tough, plantar ligaments.
- The plantar ligaments tend to
be much stronger than the dorsal ligamentous complex.
- The ligamentous connection between the
first and second metatarsal bases is weak relative to those between the
second through fifth metatarsal bases.
- Lisfranc ligament attaches the base of the
second metatarsal to the medial cuneiform.
Mechanism of Injury
- Direct:
Secondary to a heavy object impacting the dorsum of the foot, causing
plantar displacement of the metatarsals with compromise of the
intermetatarsal ligaments.
- Indirect:
More common and results from violent abduction, forced plantar flexion, or
twisting of the forefoot.
- Abduction
tends to fracture the recessed base of the second metatarsal, with
lateral displacement of the forefoot variably causing a “nutcracker†fracture of the cuboid.
- Plantar
flexion is often accompanied by fractures of the metatarsal shafts, as
axial load is transmitted proximally.
- Twisting
may result in purely ligamentous injuries.
Clinical Evaluation
- Patients
typically present with swelling over the dorsum of the foot with either an
inability to ambulate or painful ambulation.
- Deformity
is variable, because spontaneous reduction of the ligamentous injury is common.
- Tenderness
over the tarsometatarsal joint can usually be elicited; this may be
exacerbated by maneuvers that stress the tarsometatarsal articulation.
- Of
these injuries, 20% are missed initially
Radiographic Evaluation
- AP, lateral, and oblique views of the foot
should be obtained.
- AP radiograph
- The medial border of the
second metatarsal should be colinear with the medial border of the middle
cuneiform.
- A fracture of the base of the second
metatarsal should alert the examiner to the likelihood of a tarsometatarsal
dislocation, because often the dislocation will have spontaneously
reduced. One may only see a “fleck sign,â€
indicating an avulsion of the Lisfranc ligament.
- The combination of a fracture at the base
of the second metatarsal with a cuboid fracture indicates severe
ligamentous injury, with dislocation of the tarsometatarsal joint.
- More than 2 to
- Lateral radiograph
- Dorsal displacement of the metatarsals
indicates ligamentous compromise.
- Plantar displacement of the medial
cuneiform relative to the fifth metatarsal on a weight-bearing lateral
view may indicate subtle ligamentous injury.
- Oblique radiograph
- The medial border of the fourth
metatarsal should be colinear with the medial border of the cuboid.
Classification
Quenu and
Kuss (Fig. 28)
|
Incongruity of the entire tarsometatarsal
joint |
||
|
Type B: |
Partial instability, either medial or lateral |
|
|
Type C: |
Divergent partial or total instability |
|
|
|
||
|
Figure 28. Quenu and Kuss classification of tarsometatarsal injuries. (From Hardcastle PH, Reschauer R, Kitscha-Lissberg E, et al. Injuries to the tarsometatarsal joint: incidence, classification and treatment. J Bone Joint Surg Br 1982;64B:349.) |
||
Treatment
Nonoperative
- Minimally
displaced tarsometatarsal dislocations (<2 to
- Displaced
dislocations often respond well to closed reduction using general
anesthesia.
- This
is typically accomplished with patient supine, finger traps on the toes,
and
- If
the reduction is determined to be stable, a short leg cast is placed for
4 to 6 weeks, followed by a hard-soled shoe or cast boot until ambulation
is well tolerated.
Operative
- Surgical
management is indicated with displaced dislocations when reduction cannot
be achieved or maintained.
- Closed
reduction may be attempted as described earlier, with placement of
percutaneous Kirschner wires to maintain the reduction.
- In
the rare case when closed reduction cannot be obtained, open reduction
using a dorsal incision may be performed. Kirschner wires are utilized to
maintain reduction; these are typically left protruding through the skin
to facilitate removal.
- A
short leg cast is placed postoperatively; this is maintained for 4 weeks,
at which time the wires and cast may be discontinued and the patient
placed in a hard-soled shoe or cast boot until ambulation is well
tolerated.
Complications
- Persistent pain: May result from
unrecognized or untreated injuries to the tarsometatarsal joint caused by
ligamentous compromise and residual instability.
- Angular deformity: May result despite
treatment and emphasizes the need for reduction and immobilization by
surgical intervention if indicated.
METATARSALS
Epidemiology
- Very common injury in children and
accounts for up to 60% of pediatric foot fractures.
- The metatarsals are involved in only 2% of
stress fractures in children; in adults, the metatarsals are involved in
14% of stress fractures.
Anatomy
- Ossification of the metatarsals is
apparent by 2 months in utero.
- The metatarsals are interconnected by
tough intermetatarsal ligaments at their bases.
- The configuration of the metatarsals in
coronal section forms an arch, with the second metatarsal representing the
“keystone†of the arch.
- Fractures through the metatarsal neck most
frequently result from their relatively small diameter.
- Fractures at the base of the fifth
metatarsal must be differentiated from an apophyseal growth center or an
os vesalianum, a sesamoid proximal to the insertion of the peroneus
brevis. The apophysis is not present before age 8 years and usually unites
to the shaft by 12 years in girls and 15 years in boys.
Mechanism of Injury
- Direct:
Trauma to the dorsum of the foot, mainly from heavy falling objects.
- Indirect:
More common and results from axial loading with force transmission through
the plantar flexed ankle or by torsional forces as the forefoot is
twisted.
- Avulsion
at the base of the fifth metatarsal may result from tension at the
insertion of the peroneus brevis muscle, the tendinous portion of the
abductor digiti minimi, or the insertion of the strong lateral cord of the
plantar aponeurosis.
- “Bunk-bed
fractureâ€: This fracture of the proximal first metatarsal is caused by
jumping from a bunk bed landing on the plantar flexed foot.
- Stress
fractures may occur with repetitive loading, such as long-distance
running.
Clinical Evaluation
- Patients
typically present with swelling, pain, and ecchymosis, and they may be
unable to ambulate on the affected foot.
- Minimally
displaced fractures may present with minimal swelling and tenderness to
palpation.
- A
careful neurovascular examination should be performed.
- The
presence of compartment syndrome of the foot should be ruled out in cases
of dramatic swelling, pain, venous congestion in the toes, or history of a
crush mechanism of injury. The interossei and short plantar muscles are
contained in closed fascial compartments.
Radiographic Evaluation
- AP, lateral, and oblique views of the foot
should be obtained.
- Bone scans may be useful in identifying
occult fractures in the appropriate clinical setting or stress fractures
with apparently negative plain radiographs.
- With conventional radiographs of the foot,
exposure sufficient for penetration of the tarsal bones typically results
in overpenetration of the metatarsal bones and phalanges; therefore, when
injuries to the forefoot are suspected, optimal exposure of this region
may require underpenetration of the hindfoot.
Classification
Descriptive
- Location: metatarsal number, proximal,
midshaft, distal
- Pattern: spiral, transverse, oblique
- Angulation
- Displacement
- Comminution
- Articular involvement
Treatment
Nonoperative
- Most
fractures of the metatarsals may be treated initially with splinting,
followed by a short-leg walking cast once swelling subsides. If severe
swelling is present, the ankle should be splinted in slight equinus to
minimize neurovascular compromise at the ankle. Care must be taken to
ensure that circumferential dressings are not constrictive at the ankle,
causing further congestion and possible neurovascular compromise.
- Alternatively,
in cases of truly nondisplaced fractures with no or minimal swelling, a
cast may be placed initially. This is typically maintained for 3 to 6
weeks until radiographic evidence of union.
- Fractures
at the base of the fifth metatarsal may be treated with a short-leg
walking cast for 3 to 6 weeks until radiographic evidence of union.
Fractures occurring at the metaphyseal-diaphyseal junction have lower
rates of healing and should be treated with a non–weight-bearing
short leg cast for 6 weeks; open reduction and intramedullary screw
fixation may be considered, especially if a history of pain was present
for 3 months or more before injury, which indicates a
chronic stress injury.
- Stress
fractures of the metatarsal shaft may be treated with a short leg walking
cast for 2 weeks, at which time it may be discontinued if tenderness has
subsided and walking is painless. Pain from excessive metatarsophalangeal
motion may be minimized by the use of a metatarsal bar placed on the sole
of the shoe.
Operative
- If
a compartment syndrome is identified, release of all nine fascial
compartments of the foot should be performed.
- Unstable
fractures may require percutaneous pinning with Kirschner wires for
fixation, particularly with fractures of the first and fifth metatarsals.
Considerable lateral displacement and dorsal angulation may be accepted in
younger patients, because remodeling will occur.
- Open
reduction and pinning are indicated when reduction cannot be achieved or
maintained. The standard technique includes dorsal exposure, Kirschner
wire placement in the distal fragment, fracture reduction, and
intramedullary introduction of the wire in a retrograde fashion to achieve
fracture fixation.
- Postoperatively,
the patient should be placed in a short leg, non–weight-bearing
cast for 3 weeks, at which time the pins are removed and the patient is
changed to a walking cast for an additional 2 to 4 weeks.
Complications
- Malunion: This typically does not result
in functional disability because remodeling may achieve partial
correction. Severe malunion resulting in disability may be treated with
osteotomy and pinning.
- Compartment syndrome: This uncommon but
devastating complication may result in fibrosis of the interossei and an
intrinsic minus foot with claw toes. Clinical suspicion must be high in
the appropriate clinical setting; workup should be aggressive and
treatment expedient, because the compartments of the foot are small in
volume and are bounded by tight fascial structures.
PHALANGES
Epidemiology
- Uncommon; the true incidence is unknown
because of underreporting.
Anatomy
- Ossification of the phalanges ranges from
3 months in utero for the distal phalanges of the lesser toes, 4 months in
utero for the proximal phalanges, 6 months in utero for the middle
phalanges, and up to age 3 years for the secondary ossification centers.
- Direct
trauma accounts for nearly all these injuries, with force transmission
typically on the dorsal aspect from heavy falling objects or axially when
an unyielding structure is kicked.
- Indirect
mechanisms are uncommon, with rotational forces from twisting responsible
for most.
Clinical Evaluation
- Patients
typically present ambulatory but guarding the affected forefoot.
- Ecchymosis,
swelling, and tenderness to palpation may be appreciated.
- A
neurovascular examination is important, with documentation of digital
sensation on the medial and lateral aspects of the toe as well as an
assessment of capillary refill.
- The
entire toe should be exposed and examined for open fracture or puncture
wounds.
Radiographic Evaluation
- AP, lateral, and oblique films of the foot
should be obtained.
- The diagnosis is usually made on the AP or
oblique films; lateral radiographs of lesser toe phalanges are usually of
limited value.
- Contralateral views may be obtained for
comparison.
Classification
Descriptive
- Location:
toe number, proximal, middle, distal
- Pattern: spiral,
transverse, oblique
- Angulation
- Displacement
- Comminution
- Articular involvement
Treatment
Nonoperative
- Nonoperative
treatment is indicated for almost all pediatric phalangeal fractures
unless there is severe articular incongruity or an unstable, displaced
fracture of the first proximal phalanx.
- Reduction
maneuvers are rarely necessary; severe angulation or displacement may be
addressed by simple longitudinal traction.
- External
immobilization typically consists of simple buddy taping with gauze
between the toes to prevent maceration; a rigid-soled orthosis may provide
additional comfort in limiting forefoot motion. This is maintained until
the patient is pain free, typically between 2 and 4 weeks (Fig.
29).
- Kicking
and running sports should be limited for an additional 2 to 3 weeks.
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Figure 29. Method of taping to adjacent toe(s) for fractures or dislocations of
the phalanges. Gauze is placed between the toes to prevent maceration. The
nailbeds are exposed to ascertain that the injured toe is not malrotated. (From Weber BG, Brunner C, Freuler F. Treatments of Fractures in Children and Adolescents. New York: Springer-Verlag, 1980:392.) |
Operative
- Surgical
management is indicated when fracture reduction cannot be achieved or
maintained, particularly for displaced or angulated fractures of the first
proximal phalanx.
- Relative
indications include rotational displacement that cannot be corrected by
closed means and severe angular deformities that, if uncorrected, would
lead to cock-up toe deformities or an abducted fifth toe.
- Fracture
reduction is maintained via retrograde, intramedullary Kirschner wire
fixation.
- Nailbed
injuries should be repaired. Open reduction may be necessary to remove
interposed soft tissue or to achieve adequate articular congruity.
- Postoperative
immobilization consists of a rigid-soled orthosis or splint. Kirschner wires are
typically removed at 3 weeks.
Complications
- Malunion uncommonly results in functional
significance, usually a consequence of fractures of the first proximal
phalanx that may lead to varus or valgus deformity. Cock-up toe
deformities and fifth toe abduction may cause cosmetically undesirable
results as well as poor shoe fitting or irritation.