Major Amputations of the Upper Extremity

Many orthopaedic surgeons consider amputation as a failure to restore function to an individual; however, an amputation should be considered the start of rehabilitation. Major amputations of the upper extremity are classified as being from the wrist distally to the axilla proximally. Major amputations of the upper extremity account for 8% of all amputations and are approximately 20 times less common than amputations of the lower extremity. Over 100,000 people in the United States are living with major upper extremity amputations today. Trauma is the most common reason for upper extremity amputations, with male predominance much greater than female. Shoulder disarticulation and forequarter amputations are performed more commonly for malignant tumors.

Most traumatic amputees benefit more from completion of the amputation and early prosthetic fitting than from heroic attempts at salvage procedures. However, most patients prefer reimplantation if possible over amputation because prostheses currently confer little in the way of sensation and psychological wellbeing. Approximately 13% of patients develop major complications after amputation.

Generally, all possible length should be preserved in upper extremity amputations. Length preservation can be maintained by careful evaluation and lengthening of a short stump by distraction osteogenesis (the method of Ilizarov) and microvascular anastomosis. Distal-free flaps and spare-part flaps (fillet flaps) from the amputated limb also should be used to preserve length. A shortening osteotomy may be required on occasion. However, prosthetists are able to fit even small stumps with prostheses to improve function. Often a small stump distal to the elbow can functionally be better than a long above-elbow amputation. A prosthetic limb cannot adequately replace the sensibility of the hand, and the function of a prosthetic limb decreases with higher levels of amputation. Few patients with amputations around the shoulder are regular prosthetic users. The use of a rigid dressing and subsequent early temporary prosthetic fitting (within 30 days) in patients with transhumeral or more distal amputations encourages the resumption of bimanual activities, softens the psychologic blow of limb loss, and decreases the prosthetic rejection rate. After 4 to 6 weeks postoperatively, the soft tissues have healed significantly, and the edema should be controlled enough to proceed with a definitive socket for the patient. A myoelectrical prosthesis may be an option for patients with a below-elbow amputation. These prostheses continue to evolve rapidly. The first-generation myoelectric prostheses used electromyographic (EMG) signals and allowed motion in only one plane (flexion and extension). EMG with the addition of targeted muscle reinnervation (TMR) allows more motion and more intuitive use of the prosthesis. Currently the addition of pattern recognition with TMR actually predicts the motion that is about to occur. However, with these advances the algorithms are limited to sequentially controlling the degrees of freedom to only two at a time. This is the limiting factor that keeps these advances from mimicking a natural limb. In manual workers, a more traditional device may be more effective. Some institutions use hybrid systems consisting of a locking shoulder joint with a body-powered elbow and externally powered wrist and terminal devices. These systems are most useful in amputations of the dominant extremity. Recipients use the prosthesis for approximately 14 hours a day. Some reports indicate that 50% of patients discontinue the use of the prosthesis after 5 years. Prosthetic rejection rates can be decreased with better patient education, more distal amputation levels, and prosthetic fitting within 30 days. Various terminal devices are available and are easily interchanged ( Fig. 18.1 ). Phantom pain has been reported in over 50% of patients; however, it rarely causes impaired prosthetic use or unemployment. Myodesis, myoplasty, and myofascial closures should all be performed when possible.

New techniques of upper extremity amputations are evolving rapidly with the use of TMR, EMG pattern recognition, and to a lesser degree composite tissue allotransplantation. A multi-disciplinary team approach, including an experienced upper extremity surgeon, a skilled prosthetist or orthotist, a pain management physician, and a skilled physical therapist, should be employed. To obtain this most patients benefit from transfer to a level I hospital. Regardless, experienced prosthetists are invaluable in ensuring that patients have proper functional devices, and they should be consulted, when available, for each patient preferably before surgery.

Hand Amputations

Hand amputations are discussed in Chapter 19 .

Wrist Amputations

Whenever feasible, transcarpal amputation or disarticulation of the wrist is preferable to amputation through the forearm because, provided that the distal radioulnar joint remains normal, pronation and supination are preserved. Although only 50% of any pronation and supination is transmitted to the prosthesis, these motions are extremely valuable to the patient, and every effort should be made to preserve them. In transcarpal amputations, flexion and extension of the radiocarpal joint also should be preserved so that these motions, too, can be used prosthetically. Although difficult, prosthetic fitting of transcarpal amputation stumps can be achieved by a skilled prosthetist. Excellent wrist disarticulation prostheses are now available, and thin prosthetic wrist units can be used that, to a considerable extent, eliminate the previous objection of the artificial hand or prosthetic hook extending below the level of the opposite hand. Compared with more proximal amputations, the long lever arm afforded by amputation at the wrist increases the ease and power with which the prosthesis can be used.

Amputation at the Wrist

Technique 18.1

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Fashion a long palmar and a short dorsal skin flap in a ratio of 2:1. Use the thick palmar skin when available. Dissect the flaps proximally to the level of proposed bone section and expose the underlying soft structures.
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Draw the tendons of the finger flexors and extensors distally, divide them, and allow them to retract into the forearm.
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Identify the tendons of the wrist flexors and extensors, free their insertions, and reflect them proximal to the level of bone section. Identify the median and ulnar nerves and the fine filaments of the radial nerve. Draw the nerves distally and section them well proximal to the level of amputation so that their ends retract well above the end of the stump to help avoid a residual painful neuroma.
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Just proximal to the level of intended bone section, clamp, ligate, and divide the radial and ulnar arteries, and divide the remaining soft tissues down to bone.
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Transect the bones with a saw and rasp all rough edges to form a smooth, rounded contour.
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At convenient points in line with their normal insertions, anchor the tendons of the wrist flexors and extensors to the remaining carpal bones so that active wrist motion is preserved.
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With interrupted nonabsorbable sutures, close the subcutaneous tissue and skin at the end of the stump, and insert a rubber tissue drain or a plastic tube for suction drainage.

Disarticulation of the Wrist

Technique 18.2

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Fashion a long palmar and a short dorsal skin flap ( Fig. 18.2A ). Begin the incision 1.3 cm distal to the radial styloid process, carry it distally and across the palm, and curve it proximally to end 1.3 cm distal to the ulnar styloid process.
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Form a short dorsal skin flap by connecting the two ends of the palmar incision over the dorsum of the hand; atypical flaps may be fashioned, if necessary, to avoid amputation at a higher level. Reflect the skin flaps together with the subcutaneous tissue and fascia proximally to the radiocarpal joint.
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Just proximal to the joint, identify, ligate, and divide the radial and ulnar arteries.
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Identify the median, ulnar, and radial nerves and gently draw them distally into the wound. Section them so that they retract well proximal to the level of the amputation. Also identify the superficial radial nerve, the palmar cutaneous branch, and the dorsal ulnar cutaneous nerve. Preserve the cutaneous nerves that supply sensation to the residual skin stump.
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At a proximal level, divide all tendons and perform a tenodesis of the flexors and extensor tendons.
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Incise the wrist joint capsule circumferentially, completing the disarticulation ( Fig. 18.2B, C ).
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Retain if possible or resect (if they prevent tensionless closure) the radial and ulnar styloid processes and rasp the raw ends of the bones to form a smoothly rounded contour. Take care to avoid damaging the distal radioulnar joint, including the triangular ligament, so that normal pronation and supination of the forearm are preserved and pain in the joint is prevented ( Fig. 18.2D ).
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With interrupted nonabsorbable sutures, close the skin flaps over the ends of the bones ( Fig. 18.2E ) and insert a rubber tissue drain or a plastic tube for suction drainage.

Forearm Amputations (Transradial)

Transradial amputations represent 40% of all major upper extremity amputations. As elsewhere, preserving as much length as possible is desirable. We recommend preserving a minimum of two thirds of the forearm length when possible. When circulation in the upper extremity is severely impaired, however, amputations through the distal third of the forearm are less likely to heal satisfactorily than those at a more proximal level because distally the skin is often thin and the subcutaneous tissue is scant. The underlying soft tissues distally consist primarily of relatively avascular structures, such as fascia and tendons. In these exceptional circumstances, an amputation at the junction of the middle and distal thirds of the forearm is preferable. In amputations through the proximal third of the forearm, even a short below-elbow stump 5 cm long is preferable to an amputation through or above the elbow because it preserves elbow function at this level and allows for prosthetic suspension. From a functional standpoint, preserving the patient’s own elbow joint is crucial (5 cm of ulna). By using improved prosthetic fitting techniques, a skilled prosthetist can provide an excellent prosthetic device for even a short below-elbow stump. The benefits of TMR to transradial amputees can be substantial.

Distal Forearm (Distal Transradial) Amputation

Technique 18.3

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Beginning proximally at the intended level of bone section, fashion equal anterior and posterior skin flaps ( Fig. 18.3A ); make the length of each about equal to one half of the diameter of the forearm at the level of amputation. Together with the skin flaps, reflect the subcutaneous tissue and deep fascia proximally to the level of bone section.
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Clamp, doubly ligate, and divide the radial and ulnar arteries just proximal to this level.
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Identify the radial, ulnar, and median nerves; draw them gently distally; and transect them high so that they retract well proximal to the end of the stump.
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Cut across the muscle bellies transversely distal to the level of bone section and interpose the muscle tissue between the radius and the ulna. Distally, use the pronator quadratus and more proximally use one flexor tendon and one extensor tendon. Tenodese these muscles to the bone to help prevent painful convergence and instability.
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Divide the radius and ulna transversely and rasp all sharp edges from their ends ( Fig. 18.3B ).
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Close the deep fascia with fine absorbable sutures and the skin flaps with interrupted nonabsorbable sutures ( Fig. 18.3C ) and insert deep to the fascia a rubber tissue drain or, if preferable, a plastic tube for suction drainage.
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A myoplastic closure should be done in this amputation as follows. After raising appropriate flaps of skin and fascia, fashion an anterior flap of flexor digitorum sublimis muscle long enough so that its end can be carried around the end of the bones to the deep fascia dorsally.
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Divide the remaining soft tissues transversely at the level of bone section.
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After dividing the bones and contouring their ends, carry the muscle flap dorsally and suture its end to the deep fascia over the dorsal musculature. To prevent excessive bulk, the entire anterior muscle mass should never be used in this manner.
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Close the stump as already described.

Proximal Third of Forearm (Proximal Transradial) Amputation

Technique 18.4

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When good skin is available, fashion anterior and posterior skin flaps of equal length; if good skin is unavailable, fashion atypical flaps as necessary rather than amputate at a more proximal level. Reflect proximally the deep fascia together with the skin flaps to the level of intended bone section.
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Just proximal to this level, identify, doubly ligate, and divide the major vessels.
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Identify the median, ulnar, and radial nerves; gently pull them distally; and section them proximally so that their ends retract well proximal to the end of the stump.
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Divide the muscle bellies transversely distal to the level of bone section so that their proximal ends retract to that level. Carefully trim away all excess muscle.
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Divide the radius and ulna transversely and smooth their cut edges. Attempt to maintain at least 5 cm of the ulna proximally. If a more proximal osteotomy is required, tenodesis of the biceps tendon to the proximal portion of the residual ulna is needed. This lengthens the stump functionally and enhances prosthetic fitting. Even without biceps function, the elbow can be flexed satisfactorily by the brachialis muscle.
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With interrupted absorbable sutures, close the deep fascia; with interrupted nonabsorbable sutures, close the skin edges. Insert deep to the fascia a rubber tissue drain or a plastic tube for suction drainage.

Elbow Disarticulation

The elbow joint is an excellent level for amputation because the broad flare of the humeral condyles can be grasped firmly by the prosthetic socket and humeral rotation can be transmitted to the prosthesis. In more proximal amputations, humeral rotation cannot be thus transmitted, so a prosthetic elbow turntable is necessary. The difficulties previously experienced in prosthetic fitting at this level have been overcome by modern prosthetic techniques, and most surgeons now believe that disarticulation of the elbow is usually preferable to a more proximal amputation.

Additionally, a humeral shortening osteotomy can be done to preserve the elbow.

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