LECTURE 10

LECTURE 10.

AMPUTATIONS AND DISARTICULATIONS

 

Amputation is the intentional surgical removal of a limb or body part. It is performed to remove diseased tissue or relieve pain. Traumatic amputation is the loss of a body part – usually a finger, toe, arm, or leg – that occurs as the result of an accident or trauma. So, amputations is removal of peripheral limb part at different levels of a bone (between joints).

Disarticulation is the surgical removal of peripheral part of limb at articulation level.

 

History of the Procedure

Amputation is one of the oldest surgical procedures. Archaelogists have uncovered evidence of amputation in prehistoric humans.

Hippocratus recommended to cut a limb within necrotic tissue because in that case bleeding was absence. It is clear, because in that time methods of arest of bleeding were imperfect (even barbarian). Arest of bleeding was realized by hot iron cauterization of vessels and surrounding tissue, and this procedure led to necrosis of stump tissue and traumatic shock.

In A. D. 1^st centure Cels has offered to perform an amputation of limb within health tissue, to cut a bone above a soft tissue, and to ligate a vessels by ligature for arrest of bleeding.

 

Indications

All indications to amputations or disarticulations we can divide into 2 group:

1.     absolute

2.     relative

 

First one is the indications when irreversible processes are present and conservative (therapeutic) methods of treatment cann’t to save a limb.

·        traumatic limb rupture

·        gangrene (as result of burn, electrotrauma, endarteritis,frostbite, embolism, anaerobic infection, diabetic angiopathy)

·        the third indication consists of 3 signs:

1) injure of 2/3 of soft tissue

2) injure and crushing of major vasculo-nervous bundles

3) injure of a bone.

 

Second (relative) indications is the indications when surgery is necessary just in that cases when trauma or disease of limb can led to death of patient.

·        acute infectious process (for example, gas gangrene)

·        chronic infection (chronic osteomyelitis, tuberculosis of bones and joints)

·        massive trophic ulcer

·        irreparable deformation of limb (congenital, posttraumatic, paralytic)

·        limb injure with damage of 2/3 of soft tissue and bone on considerable distance but without injure of vasculo-nervous bundle.

 

In according to Kuprianoff, all indications are dividing into three groups:

1.    primary amputation

2.    secondary amputation (intermediate, intrapyretic)

3.    re-amputation (repeated amputation).

 

Primary amputation is performed in earlier termes before development of infections (within first 24 hours). This type of amputation is first surgical debridment of wound.

Secondary amputation is performed in case of development of wound infection. This amputation is called as delayed amputation and is performed after 7-8 days.

Re-amputation – reasons for this amputation are bad results after first amputation. For example, faulty stump or re-amputation for prosthesis fitting.

 

Contraindications

The only absolute contraindication to amputation an instance in which sparing a limb or part of a limb would leave the patient better able to function than would an amputation.

Relative contraindication is traumatic shock. It is necessary to treat a shock at first and than to perform a surgery. But it cann’t be more than 4 hours.

 

General principles

I.                   Any amputation has for an object:

1)     to prevent spreading of infection and entrance of products of metabolism from the wound to victim’s organism, and by this way, to save his life.

2)     to perform functional stump for future prosthesis.

II.                Majority of amputations and disarticulations are performed with appling of elastic rubber tourniquet (another types of tourniquets cann’t be used). A surgeon cann;t use a tourniquet when amputation is performed because of gas gangrene or obliterating endarteritis. Major vessels must be ligated before amputation. Bleeding from small vessels is stopped during surgery.

III.             Determination of level of amputation (level of bone cutting). Before an amputation is performed, extensive testing is done to determine the proper level of amputation. The goal of a surgeon is to find the place where healing is most likely to be complete, while allowing the maximum amount of limb to remain for effective rehabilitation. It is clear, that short stump as result of higher amputation is worse for prosthetic device. Pyrogoff said that: “It is necessary to operate as low as it possible”.

So, level of amputation must be the best for victim for following fitting with a prosthetic device.

 

Steps of amputation

General principle of amputations and disarticulations is that all of them are performed by three steps:

I – cutting of soft tissue

II – treatment of periosteum and cutting of a bone

III – stump treatment.

 

I step of amputation – cutting of soft tissue

All amputations are divided into closed and circular amputation in according to cutting of soft tissue.

 

Closed (flap) amputations are divided into single- and double-flap amputation.

Single-flap amputation – bone stump is covered by one flap formed from skin, subcutaneous tissue, superficial and proper fascia. This type of amputation is called as fascioplastic. If a flap contains periosteum, it will be fascioperiosteoplastic method.

After creation of a flap a postoperative scar must be located on non-working (unbearing) surface of stump.

Working surfaces for:

·        lower extremity: anterior and lower

·        upper extremity: palmar

·        I finger – palmar and ulnar surfaces

·        II finger – palmar and radial surfaces

·        V finger – palmar and ulnar surfaces

·        III, IV fingers – palmar surface.

Double-flap amputation – bone stump is covered by two flaps created from opposite limb surfaces. This type of amputation could be fascioplastic and fascioperiosteoplastic.

 

It is very important to calculate a length of creating flap. This calculation we can express by the formula of length of circumference:

C=2πr,

C=πd,

Where C – length of circumference

π – constant value, 3,14

r – radius of circumference of limb at level of amputation

d – diameter of circumference.

In case of single-flap amputation length of flap is equal to diameter of a limb at level of amputation.

C=2πr= πd

D=C/π=C/3,14≈C/3.

 

So, diameter is equal to one third of circumference of limb. A circumference we can measure (evaluate) by any lace (belt).

As you understand, when we measure the circumference of limb at level of amputation and this number divide by three we will get length of flap in case of single-flap amputation.

In case of double-flap amputation lengthes of both flaps in sum must be equal to diameter of limb at level of amputation. Longer flap is equal to 2/3 of diameter, shorter – to 1/3 of diameter.

Except this, it is necessary to take into account a skin contractile (retrench).

We must add some cm to flap length for calculation of coefficient (factor) of skin contraction.

 

Coefficient of skin contraction

K=1/6*C or K=C/6.

This value is divided by two.

 

Circular amputation

Soft tissue is cutted perpendiculary to longitudinal axis of a bone.

These amputations are divided into three types in according to methods of cutting of soft tissues:

·        one-step amputation

·        two-step amputation

·        three step amputation.

 

One-step amputation (guillotine amputation). All soft tissues (skin, subcutaneous tissue, superficial and proper fasciae, and muscles) are cutted the limb across at the level of amputation. Cutting of a bone on the same level.

It is an amputation that could be done quickly, and speed of surgery is sometimes very essential (anaerobic infection, for example). But this type of amputatioeeds re-amputation in any cases because of faulty stump forming. After healing of the wound by secondary infection, revision of the stump usually is necessary to make it suitable for wearing a prosthesis comfortably.

 

Two-step amputation. Soft tissues are cutted in two motions (stages):

first – skin, subcutaneous tissue, superficial and proper faciae,

second – cutting of muscles at level of contracted skin.

Deficiency of this method is forming of a scar at bearing or working surface of the stump.

Variety of two-step circular amputation is forearm amputation by “cuff” method.

First step – cutting of skin, subcutaneous tissue, superficial and proper faciae. Then all these layers are separated and tucked up like a cuff of sleeve in proximal direction of a limb. Length of a cuff is calculated like in case of double-flap amputation. But use smaller diameter of forearm at level of amputation (because it has ellipse-shaped form). Second step – muscle cutting until the bone at level of turned cuff.

Three-step amputation.

As ussual, this type of amputation is performed on thigh or arm (where just one bone is present). In this case soft tissues are cutted in three motions on different levels.

First step – cutting of skin, subcutaneous tissue, superficial and proper faciae.

Second step – cutting of superficial muscles at level of contracted skin.

Third step – cutting of deep muscles.

Another name of three-step amputation is conico-circular amputation because soft tissues are cutted by circular method. As result of different levels cutting we’ll have cone-shaped stump with apex situated on bone-stump.

Merit: three-step circular amputation is easy to perform.

Deficiency: 1) this method is uneconomical. In the same time flap amputations use tissues more economical but it is difficult to perform.

2) forming of central postoperative scar that situated on bearing surface of stump.

Conico-circular amputation is indicated in case of gas infection.

So, guillotine amputation (one-step) and conico-circular amputation (three-step) are preliminary and need re-amputation for prosthetics.

 

II step of amputation – treatment of periosteum and cutting of a bone

In this time two methods of periosteum treatment are used:

 

A)  aperiosteal

B)   subperiosteal.

Aperiosteal – periosteum is cutted at level of supposed bone section by circular incision. After that periosteum is dislocate distally with the rasp. And bone is cutted on 2 mm below than level of periosteum incision.

Why 2 mm? For prevention injure of periosteum of residual bone because it could led to forming of faulty stump and osteophytes. It is impossible to scoop out bone marrow from the bone canal, as was recommended earlier because it led to osteophytes forming or necrosis and osteomyelitis of a bone.

We cann’t left bone without periosteum more than 2 mm because of terminal necrosis of a bone.

Subperiostal method. In this case periosteum is cutted lower than supposed bone section at distance equal to bone radius plus 2 mm and separated in proximal direction.

Periosteum is stitched above a bone stump after its cutting. Injure of periosteum could led to osteophytes forming.

Periosteum treatment in children is performed by subperiosteal method, in old persons – by aperiostal method (because periosteum closely attaches to bone).

 

III step of amputation – stump treatment

This stage includes treatment of vessels, nerves and stitching of soft tissues above the bone stump.

 

Treatment of vessels.

Main vessels must be fixated by a clamp and ligated by two catgut ligatures. Small vessels – fixated by a clamp and ligated after removing of the torniquet.

During stump treatment it is necessary to realize hemostasis for prevention secondary infection.

 

 

Treatment of nerves

It is performed for prevention ingrowth of nervous fibers into a scar formation of neuromas and beginnings of phantom pains.

There are many methods of treatment of nervous trunks:

A – stitching of cutted nerves to side of same nerve under epineurium

B – angular section of nerve with following epineurium stitching

C – stitching of terminal parts of nerves.

 

In this time the best method of nerves treatment is its cutting (re-amputation of nerve) by very sharp razor on 6-8 cm above the level of amputations.

Why 6 cm? Speed of nervous fibers growing is approximately 1 mm per 24 hours. Postoperative scar forms during 2 monthes (if wound will heal by primary intention). In this case nervous trunk don’t ingrow into the scar it prevent phantom pain.

Before section of nerve it is necessary to exposure nervous trunk by bluntly dislocation of soft tissues. After exposure – 2 % solution of novocaine is injected under epineurium. It is necessary to cut all nervous branches (cutaneous too). We cann’t cut nerves more than it’s need because of forming of atrophy of stump tissues.

 

Stump stitching

Surgeon stitches skin with subcutaneous tissue, superficial fascia and proper fascia and don’t stitches muscles above the bone stump. They found new points of attachment and growe together with a bone themselves. Postoperative scar must be moveable and don’t connects with a bone.

Bone stump don’t cover by a muscle on lower limb because they will atrophy after fitting of prosthetic device. Fasciomyoplastic method of stump covering is used on upper limb. For this purpose tendons of antagonist muscles are stitched to each other. This surgical procedure is called myoplasty.

Another approach to managing the muscle on the limb during amputation is myodesis. With a myodesis, the muscles and fasciae are sutured directly to the distal residual bone through drill holes. Myodesis is contraindicated in patients with severe peripheral vascular disease, because the blood suppling to the muscles may be compromised.

 

Complications

The most common complications of amputations are:

·        massive hemorrage that occurs when a suture becomes loose

·        infection

·        rash, blisters, and skin breakdown caused by immobility, pressure, and other sources of irritation

·        pneumonia, blood clots, and breathing problems associated with immobility

·        formation of nerve cells tumor (neuromas) at severed nerve endings

·        joint contractures, phantom limb pain, neuroma formation, stump breakdown, and, in children, bone overgrowth.

 

Mistakes of I step of amputation

1.     Conical stump – lack of soft tissue because of wrong calculation during I step of amputation in case of flap-amputation or guillotine amputation.

2.     Mace-shaped stump – is characterized by surplus of soft tissues, and wrong calculations of flap length or level of amputation in case of circular amputation.

Mistakes of II step of amputation

3.     Terminal necrosis of bone – as result of excessive removing of periosteum (more than 2 mm from residual part of a bone).

4.     Forming of large osteophytes – as result of injure of periosteum on residual part of bone during it’s sawing or after scooping out an bone marrow.

Mistakes of III step of amputation

5.    Forming of trophic ulcer – as result of: a) wrong level of amputation; b) higher ligation of arteries and cutting of nerves.

6.    Phantom pain – as result of ingrowing of nerves fibres into a scar.

 

7.    Chronic osteomyelitis – forms because of secondary infection inside the wound.

All these complications led to defect of stump development, and need correction – performing of re-amputation.

 

Phantom pain

feels like it’s coming from a body part that’s no longer there. Experts now recognize a physical cause for this pain – and that it actually originates in the brain. Most people who’ve had a limb removed report that it sometimes feels as if their amputated limb is still there. Now experts recognize a physical cause for this pain – and that it actually originates in the brain. Most people who’ve had a limb removed report that it sometimes feels as if their amputated limb is still there. This painless phenomenon, known as phantom limb sensation, can also occur in people who were born without limbs.

 

 

Osteo-plastic amputation

Keep in your memory, that this type of amputation always is repeated amputation (re-amputation).

Performing of it is possible when wound is clean (without any smallest infection). So, osteo-plastic amputation cann’t be performed because of primary indications. Exception of this rule is malignant tumors.

First and third steps of amputation are analogical to ordinary amputation. Second step has some peculiarities – forming of osteo-periosteal flap by which surgeon covers a cutted bone.

Pyrogoff proposed to cover the cutted leg bones by a flap created by skin, subcutaneous tissue, superficial fascia and tuber of heel bone with periosteum.

Gritti’s method – cutted femoral bone is covered by osteo-periosteal flap created by patella.

Albreht’s method – form tenon from patella and fixate it in intramedullary canal of femur.

 

Osteo-plastic amputation is never performed at upper limb!!! In case of amputations a surgeon tries to perform cinematization of forearm stump because of its’ functional peculiarities (Krukenberg’s surgery). For this purpose ulnar and radial bones are separated one from another. Muscles are divided into two groups: radial and ulnar.

 

Peculiarities of amputation in children

Disarticulations are preferred in children because amputations (through bone) tend to be less satisfactory because continued irregular growth of bone at the amputation causing stump pressure points and discomfort.

The image demonstrates a Symes’ amputation, the commonest amputation of lower extremity performed in children. The Syme’s procedure is an ankle disarticulation with a long posterior flap brought forward. This provides an end bearing stump and preserves physeal growth. The malleoli are not trimmed.

 

You have to remember that:

1.                            bones grow more quickly than soft tissues. It cause forming of conical stump with following trophical ulcers. For prevention this complication it is necessary to leave surplus of soft tissues.

2.                            another fact – pair bones (arm, leg) grow with different speed. So, radial and fibular bones grow quickly. Because of it cutting of these bones must be performed higher.

3.                            growth zones are present in child’s bones. At amputation, surgeons must cut below to this plate for prevention dysproportional growing of extremities in future.

 

Terminal overgrowth occurs to some degree in all children with amputation. Pediatric patients with disarticulations don’t demonstrate terminal overgrowth because the articular cartilage acts as a natural barrier to this activity. For this reason, disarticulations are the treatment of choice in children whenever possible. The only treatment for symptomatic terminal overgrowth is revision amputation.

After surgery a soft, compressive dressing is applied to the stump. If a drain is used, it’s removed within 24-48 hours.

Following an amputation, the patient usually waits six to eight weeks before being fitted with a prosthetic device.

 

Types of amputations (lower extremity):

• Transphalangeal amputation – Excision of part of 1 or more toes

• Toe disarticulation amputation – Resection through the metatarsophalangeal joint or joints

• Ray amputation – Resection of the toe and part or all of the corresponding metatarsal

• Transmetatarsal amputation – Resection through all metatarsals

• This amputation is designed to provide a functional, weight-bearing foot with an adequate forefoot lever arm to permit reasonably normal walking without major prosthetic restoration. 

• Lisfranc amputation – Resection through the metatarsal and tarsal joints

• Because the insertions of the dorsiflexors of the ankle are sacrificed with this amputation, to provide for a balanced ankle and avoid development of an equinovarus deformity the distal tendons of the peroneus brevis and the anterior tibialis must be reattached proximally in the residual foot to the cuboid and to the neck of the talus, respectively.

• The shape and shortened length of the residual foot increases the difficulty of fitting it with a partial foot prosthesis that can provide adequate suspension and/or a forefoot lever for ambulation. Successful prosthetic restoration often requires a prosthetic or orthotic design that is more substantial and extends proximal to the ankle.

• Chopart amputation – Resection through the calcaneocuboid and talonavicular joints

• To prevent equinovarus deformity, the peroneus brevis tendon must be transferred to the cuboid and the anterior tibialis tendon must be transferred to the neck of the talus.

• The shape and length of the residual limb make the limb even more difficult to fit with a partial foot prosthesis than it would be after the Lisfranc amputation.

• Syme amputation – Ankle disarticulation with or without removal of the medial/lateral malleoli and distal tibia/fibula flares

• The advantage of this amputation is that it provides a residual limb with an end-bearing surface.

• The length of the residual limb limits the prosthetic foot options compared with a more proximal transtibial (below-knee) amputation.

• This amputation leads to a poorer cosmetic prosthetic result because of the need for the prosthesis to accommodate the bulbous distal shape of the residual limb (which is produced by the malleoli). This is especially true for slim patients.

• Careful surgical technique is required to prevent heel pad migration from the distal end of the residual limb. If this occurs, the weight-bearing advantage of this amputation level could be compromised.

• Transtibial amputation – Below-knee amputation (BKA); resection through the tibia and fibula

• The ideal length is from the proximal one third to the middle of the limb. 

• Knee disarticulation amputation – Through-the-knee amputation; resection through the knee joint

• The advantage of this amputation is that can provide a broad, end-bearing surface for the residual limb and a maximal lever arm for powering and controlling a prosthesis

• The disadvantage of this amputation is that it does not provide an ideal length for prosthetic restoration, because it limits the amount of space available for the knee joint components in the prosthesis. This limits the options for prosthetic knees that can be used to maintain the symmetry of the knee-joint centers.

• Transfemoral amputation – Above-knee amputation (AKA)

• The ideal length is about 8 cm proximal to the knee joint, so that the femoral condyles are excised with adequate room to accommodate prosthetic knee options

• Hip disarticulation amputation – Resection through the hip joint; pelvis intact

• Hemipelvectomy amputation – Resection of all or part of the hemipelvis and of the entire lower extremity