43. Amputations

Fig. 43.1

(a) AKA with a draining sinus and distal sequestrum, probably from excessive stripping of periosteum. (b) The sequestered specimen was loose and easily removed. The stump was debrided, left open, and closed in 3 days

Wound Closure

As for all wounds , dead space should be avoided and closure achieved under physiologic tension, with excess skin trimmed as necessary to avoid dog ears but without compromising the vascularity of the flap. We recommend drains, as hematomas impair stump healing. Delayed closure should always be the case for trauma patients. It should also be the case for most infected patients such as diabetics or patients with chronic ulcers. There is no role for guillotine amputations, except in the rare lifesaving extrication situation. There is no contraindication for a split-thickness skin graft over healthy muscle of a stump. It should be as thick as possible to minimize the risk of break down (See Chap. 14 Plastics).

If the stump is closed primarily, a loose, bulky, compressive dressing is applied. The drain is removed at the first dressing change, in 24–48 h, and a new dressing applied that should be changed at suture removal (2–2.5 weeks) unless there is fever, drainage, foul odor, and increased pain—all signs of potential infection.

If the stump wound is left open at the initial surgery, it should be dressed with a bulky absorbent dressing using fluffed gauzes and light compression with elastic bandages. Do not fold back or twist the flaps while applying this dressing for fear of injuring the flap’s blood supply. This dressing is only removed in the operating room at the time of delayed primary closure 4–5 days later. Subsequent management is the same as for a primarily closed stump.

Postoperative Management

POP back slabs for upper extremity and below-knee amputations are useful for comfort and preventing early contractures. Compressive dressings and distal elevation help control edema and pain. Avoid propping AKA stumps on pillows that lead to hip flexion contractures. For patients with BKAs, do not allow knee flexion over pillows, leading to knee flexion contractures. Patients with above-knee or through-knee amputations should spend time each day lying prone (Fig. 43.2). An active rehabilitation regimen will prevent joint contractures and stiffness, strengthen the antagonist muscles across the distal joint and proximal accessory muscles, and maximize active ROM. Adequate nutrition and cessation of smoking are important adjuncts.

../images/270913_2_En_43_Chapter/270913_2_En_43_Fig2_HTML.png — Fig. 43.2

While in the prone position, gravity combats BKA flexion contracture of the knee and AKA flexion contracture of the hip. Elbow push-ups stretch the flexors even more. Prone lying should be done twice a day for 30 min

After suture removal, compressive dressings with an elastic stump bandage (Fig. 43.3) will help the stump mold and mature until it is ready for the first fitting, usually around 3 months. Complete stump maturation takes around 12 months. In low-resource environments, unless in expert hands, immediate or early rigid dressings should not be used. Early temporary prostheses are rarely available.

../images/270913_2_En_43_Chapter/270913_2_En_43_Fig3_HTML.png — Fig. 43.3

Diagram of proper stump wrapping to promote shaping and edema control of stump

It is beyond the scope of this chapter to address the intricacies of prosthetic technology. In low-resource environments, basic devices are usually provided by NGOs such as Handicap International, the International Committee of the Red Cross, Johanniter International, or Mercy Ships, to name the bigger organizations. Upper extremity amputees, especially when unilateral, are usually more concerned with cosmesis than function. The capacity for inexpensive 3-D printing is rapidly growing worldwide and is a potentially easy and affordable solution to prosthetic manufacture. Lower extremity amputees require a strong, durable, and comfortable prostheses for unaided ambulation. Advanced suspension systems such as osteointegrated stems may be the way to the future, but are not at present available in these settings. The amputee needs training in the daily care of his prosthesis, access to necessary supplies such as socks or stockings, instruction in the signs and symptoms of impending stump problems, and access for maintenance, repair, or replacement of the prosthesis.

An amputation is considered successful only when rehabilitation—uncomplicated wound healing, edema control, pain management, prevention of contractures and prosthetic fitting, and independence—is complete. Rehabilitation is an ongoing process, as regular prosthetic repair and replacement will be needed. An amputee is a patient for life.

Revision Amputations

Poor healing, inadequate length, contractures, wound complications, pressure sores, overgrowth, exostoses, and pain are reasons to revise an amputation. Problems usually stem from a recurrence of the disease, an incomplete initial excision, or the stump-prosthesis interface. Erosion through the skin of a poorly covered bony stump is not uncommon, particularly in BKAs when the end of the tibia is not adequately beveled (Fig. 43.4). The same principles used in primary amputation surgery apply for revision surgery with the input of the prosthetist sought whenever possible. Scarring and atrophy make revisions technically more difficult, but they should be attempted, as the difference is often between using crutches for life and using a prosthesis. If pain can be clearly demonstrated to be from a neuroma, revision surgery with a proximal sharp neurotomy can provide dramatic relief. Determining that a neuroma is the cause of the patient’s pain is not easy. Tinel’s test, by tapping on the precise location of pain and eliciting a sharp, lancinating pain and diagnostic blocks with local anesthetic should help confirm the diagnosis.

../images/270913_2_En_43_Chapter/270913_2_En_43_Fig4_HTML.png — Fig. 43.4

(a, b) Ulceration of the skin over an ill-prepared and ill-covered tibial bony stump that was fortunately still salvageable with a proximal BKA revision

Skin sores, rashes, and dermatitis are not uncommon in long-term prosthetic users, especially if replacement socks are not available, are insufficiently laundered, or the patient’s hygiene poor. A prosthetic holiday and return to crutch use along with local and/or systemic medical treatment are usually necessary to clear the problem.

Specific Amputations

Upper Extremity (UE) (Box 43.1)

It is important to preserve as many joints as possible in upper extremity amputations no matter how short the distal segment.

Scapulothoracic and shoulder disarticulations are mutilating procedures reserved for life-threatening situations or for “hygienic” management of chronic fungating tumors of the shoulder and proximal arm.

Above-elbow amputations should preserve as much humerus as safely possible. A stump that reaches the midline in adduction allows “paddle function.” An amputation through the proximal third of the humerus is functionally the same as a shoulder disarticulation and often has an abduction contracture due to an unopposed rotator cuff. An amputation through the distal third of the humerus allows a myodesis of the brachialis/biceps complex to the posterior humeral cortex. The triceps can be sutured to the flexors by myoplasty.

Elbow disarticulation, after trimming the epicondyles, provides the longest lever arm in upper arm amputations and should be used, particularly in children.

Below-elbow amputations should be as long as possible to provide a sensate stump to use as a paddle, which can easily cross the midline with elbow flexion. Both bones should be cut at the same length. Proximal third amputations tend to have a supination contracture; those through the middle and distal third are more balanced. The distal half of the forearm is mostly tendinous, making padding of the bone ends difficult. Respect the sensory nervous distribution when designing the skin flaps.

The civil war in Sierra Leone revived interest in the Krukenberg procedure. It was initially described for blind bilateral forearm amputees, usually from mine blast injuries. The sensate two-prong claw has no active pinch capacity, but the preservation of active pronation-supination, combined with shoulder abduction and rotation, allows better function than a simple paddle. This technique is demanding, reserved for bilateral amputees, doing one side at a time—the non-dominant first—and the second only if the patient is satisfied with the first.

A disarticulation through the radiocarpal joint, preferably with a volar skin flap, is a good procedure, particularly in the pediatric population. Unless some rays are to be preserved, there is no benefit in retaining any of the carpal bones. The radial and ulnar styloids should be contoured to create a rounded, symmetrical stump.

Hand amputations. Initial debridement of industrial or agricultural wounds should be as conservative as possible, as many of these injuries appear more extensive on initial presentation than they are when properly evaluated in the OR. Tissues of questionable viability should be retained and left to declare themselves. They can be addressed at a second look, 48–72 h post-injury. Retain as many joints as possible as even a short sensate stub is more functional than a more proximal amputation. Immobilizing metacarpal and phalangeal fractures with K-wires stabilizes the bony architecture in the best functional position and promotes soft tissue healing.

Box 43.1 General Principles for Upper Extremity Amputations

Delayed primary closure is almost always preferable.
Preserve some prehension capability, either by key pinch or at least side-to-side pinch.
Stumps should be covered by sensate skin.
When a joint has lost antagonist balance, it should be pinned in a functional position to prevent contractures and allow delayed tendon transfer or arthrodesis.
A disarticulation is better than a more proximal trough-bone amputation. Even in adults, there is no need to remove the articular cartilage.
A bulky hand dressing can be stabilized with volar and/or dorsal POP slabs.
There are no indications for reimplantation.
Assume there will be no post-op hand rehabilitation.
Prostheses are rarely available and then only for cosmetic purposes.