Elbow and Above-Elbow Amputations

Upper-extremity amputations largely follow the same basic principles as any other amputation.[1] This article highlights the special considerations involved in acquired amputations at or above the elbow. Below-elbow amputations are discussed in separate articles (see Wrist and Forearm Amputations and Digital Amputations). Although acquired amputations in children are discussed (because pediatric patients deserve special consideration), patients with congenital limb amputations and deficiencies are beyond the scope of this article.

The true frequency of acquired amputation at or above the elbow is unknown. Published estimates of the number and rate of limb amputations, including upper-extremity amputations, vary significantly; totals ranging from 350,000 to 1,000,000 persons with amputations have been cited, as have rates of 20,000-30,000 persons per year for patients undergoing amputation.

Amputation is one of the oldest surgical procedures. Archeologists have uncovered evidence of amputation—congenital and acquired through surgery or trauma—in prehistoric humans. Whereas surgical amputation has evolved significantly since the days of quickly severing a limb from an unanesthetized patient and dipping the stump in boiling oil to achieve hemostasis, modern ideas of amputation and prosthetics were not developed until World Wars I and II. Particularly since the late 20th century, prosthetic research and rehabilitation engineering centers supported by federal funding have disseminated new information regarding biomechanics and prosthetic design.

With the advent of physical and rehabilitative medicine, surgeons now realize that care for a person who has undergone an amputation does not end with the removal of sutures.

As medical technology and surgical techniques are improved in the areas of peripheral vascular disease, diabetes, microsurgery and limb salvage, it is to be expected that the number of amputations will consequently decrease. Ethical questions of "technology over reason" will come to the forefront.

An example of this debate can be observed with the advent of upper-extremity transplantation. Although transplantation offers an attractive alternative to amputation, further discussion is needed to evaluate the risks and benefits of such procedures. Does the functional gain of transplantation justify the use of resources involved and commitment of the patient to lifelong immunosuppressive therapy?[2]

Although the surgical technique of amputation has stabilized and is not likely to undergo radical advances in the near future, prosthetic advances are likely to lead to improvements in function and quality of life of an individual with an amputation.[3] Likewise, much research has focused on gaining a better understanding of the problem of phantom sensation as it relates to the reorganizational changes in the somatosensory system.[4] Many questions remain unanswered.

Irreparable loss of the blood supply of a diseased or injured upper extremity is the only absolute indication for amputation, regardless of all other circumstances. Severe instances of peripheral vascular disease, traumatic injury, thermal and electrical injury, and frostbite commonly necessitate amputation.[5] The part not only has been rendered useless but is also a threat to the life of the individual because the toxic products of tissue destruction are disseminated systemically.

No injury severity score has been universally accepted as a guide for severe upper-extremity trauma. Much of the decision-making is left to the surgeon. In a study of 10 cases of mangled upper-extremity injuries, Kumar et al compared two scoring systems used for mangled lower-extremity injuries: the mangled extremity severity score (MESS) and the mangled extremity syndrome index (MESI).[6]  They found MESI to be more reliable than MESS but noted that a large prospective study would be required to confirm this difference. 

Likewise, in individuals with systemic sepsis, amputations are necessary to control an otherwise rampant infection. Occasionally, an injury or condition that does not directly affect a limb's vasculature has disabled the upper extremity to the point where a prosthesis would be functionally superior to the limb. The usual indication for amputation after nerve injury is the development of uncontrolled trophic ulcers in an anesthetic upper extremity.

In a case series that included patients with global brachial plexus avulsion injuries and lack of biologicl shoulder and elbow function, Hruby et al found above-elbow amputation and prosthetic rehabilitation to be beneficial.[7]

Amputation is rarely indicated in persons with quadriplegia, even if the upper extremities have no residual function. Often, the upper extremities help maintain balance when the patient is sitting and serve to distribute the forces of weightbearing over a larger area, thereby minimizing pressure sores.

In general, amputations in the upper extremity are also indicated for persons with malignant tumors without evidence of metastases. Even after metastases appear, amputation may be necessary for local tumor control and to relieve pain when a neoplasm has become ulcerated and infected or has caused a pathologic fracture.[8] In these oncologic cases, the indications for amputation versus a limb salvage procedure are evolving constantly and warrant individual consideration to a degree that is beyond the scope of this article.

The only absolute contraindication for amputation is a situation where sparing a limb or part of a limb would leave the patient better able to function than an amputation would.

Anatomy

The elbow joint is composed of the distal end of the humerus and the proximal ends of the radius and the ulna. The humerus contributes the humeral condyle, composed of the trochlea medially from anterior to posterior and the capitulum laterally on the anterior aspect, to the articular surface of the elbow joint. The humeral condyle itself is a rounded, almost tubelike structure that occupies most of the space of the distal end of the humerus and is located centrally. The condyle is covered in articular cartilage and allows the hooking-on of the C-shaped trochlear notch of the ulna and the concave superior aspect of the head of the radius.

The humerus has small indentations just superior to the condyle on the anterior aspect; the radial fossa (laterally) and the coronoid fossa (medially) allow the humerus to accept the head of the radius and the coronoid process of the ulna when the joint is in full flexion.

On the central aspect of the posterior humerus above the trochlea of the humeral condyle is the olecranon fossa, which allows the humerus to accept the olecranon of the ulna when the joint is in extension. The olecranon is the proximal end of the ulna, from which the C-shaped trochlea notch is carved.

For more information about the relevant anatomy, see Elbow Joint Anatomy. For a discussion of anatomy relevant to surgery, refer to individual surgical descriptions in Technique.

Procedural planning

The surgeon faces many challenges over the course of treating an individual by means of amputation. The surgeon must determine the salvageability of a limb, an assessment that is often made quickly in cases of trauma or sepsis. Once the decision to amputate has been made, the level of amputation must be determined (see the image below). The functional limitations of amputation levels and prosthetic designs, as well as the patient's emotional, physical, and vocational background, must be considered carefully, especially with upper-extremity amputations.

Thus, the surgeon walks a precarious tightrope. Preservation of length in the upper extremity is paramount, but it often can be achieved only by sacrificing stump viability, appropriate bone coverage and padding, and, occasionally, optimal prosthetic fitting.

The surgical procedure itself has its own risks from anesthesia and cardiovascular collapse, as well as early postoperative infections and pulmonary embolism. Events that occur later, and are perhaps more specific to individuals with amputations, include joint contractures, phantom limb pain, neuroma formation, stump breakdown, and, in children, bony overgrowth.[9]

Unlike some orthopedic patients, individuals with amputations should undergo comprehensive physical and emotional rehabilitation. A person with an amputation is a patient for life. Close coordination with a team of specialists in physiatry or rehabilitative medicine, as well as with a prosthetist, a physical therapist, and a psychologist, is ideal.

The following are major goals of upper-extremity amputation surgery:

• Preservation of functional length
• Durable coverage
• Preservation of useful sensation
• Prevention of symptomatic neuromas
• Prevention of adjacent joint contractures
• Minimization of short- and long-term morbidity
• Early prosthetic fitting, when applicable
• Early return of the patient to work and play

Persons who have amputations that are performed at the appropriate level and with proper surgical technique do very well. The complications (see Technique) are generally prevented or successfully managed. A patient's attitude, motivation, and desire before amputation strongly influence the overall outcome after the procedure. However, if proper follow-up care and rehabilitation are not coordinated with a multispecialty team of surgeons, physical therapists, physiatrists, prosthetists, and psychologists, then a less optimal result is inevitable.

Generally, the longer the residual stump, the greater the residual function, with or without a prosthesis. A study examining the outcomes of upper-extremity amputations found that individuals with below-elbow amputations more easily performed two-handed activities than did persons with above-elbow amputations.[10] However, there was no significant difference between the two groups with respect to the performance of activities of daily living. Patients with bilateral above-elbow amputations were more proficient with activities of daily living than they were with two-handed activities.

Rickelt et al retrospectively studied 40 patients who had a forequarter amputation (FQA) for malignant disease of the shoulder girdle.[11] They concluded that FQA may offer the only possibility of cure in locoregional disease such as sarcoma. They added, however, that in patients with axillary metastasis, FQA has no impact on survival, though local control may improve the patient's quality of life.[11]

Flurry et al studied the use of composite free fillet flaps in eight patients to cover proximal humeral and shoulder defects associated with upper-arm traumatic amputations.[12] They found that immediate soft-tissue coverage using composite free fillet flaps from amputated limbs can be successful, with few complications, and can preserve limb length while maximizing available tissue. In addition, the authors noted that including flexor muscle belly adjacent to the vascular pedicles provides additional coverage and a well-vascularized composite flap to aid in prosthetic fitting and comfort.

Clinical presentation

Patients with vascular compromise or occlusion present very differently, depending on the etiology. For example, patients with vascular occlusion secondary to acute embolic phenomena from a more proximal arterial graft typically present with a cold, pale, initially painful portion of the upper extremity with absent capillary refill.

Because of collateral circulation, the location of embolic occlusion is often difficult to determine on the basis of clinical appearance. In such individuals, arteriography or magnetic resonance angiography (MRA) confirms the location of the occlusion and assists in determining the level of intervention. In persons with acute occlusion, medical or surgical thrombolytic recanalization or vascular bypass efforts should be pursued. However, if these efforts fail or if the devascularized tissue has undergone irreversible injury, then amputation is indicated.

Incidents of chronic ischemia, such as in persons with diabetes or peripheral vascular disease, occur less often in the upper extremity than in the lower extremity. Furthermore, the incidence of chronic ischemia resulting in amputations above the elbow is uncommon, given the relative size of the vessel and the proximity to the heart. Revascularization efforts in this situation are less successful and frequently proceed to amputation. Chronic ischemic injury begins distally and usually progresses proximally to more viable tissue. For this reason, the extent of ischemic injury may not be fully appreciated soon after the initiation of clinical changes.

In individuals with chronic vascular insufficiency, patients remain quite functional for many years despite intermittent reports of mild pain with activity or cold intolerance. The only skin changes, if any, may be those of atrophy (shiny hairless skin). For example, patients may present with acute onset of pain in the ipsilateral index and long digits with no or minimal skin discoloration acutely. Over the course of 24-72 hours, skin usually turns cyanotic, and pain is replaced with decreased sensation. Provided that the patient is not acutely ill from sepsis, amputation at this time is discouraged. In persons with chronic ischemia, allowing the extent of the ischemia to declare itself clinically is far preferable.

Cyanotic fingers may turn black with time, and assumed viable tissue more proximally may follow, with cyanosis observed in the fingers. Once the progression of ischemia has stabilized, plans for definitive amputation may commence. If the level of amputation is in question, specific tests may be performed to assess the viability and healing potential of the tissue in question.

Thermal burns and frostbite rarely result in amputation more proximal to the hand. However, with extensive injury, amputation may be required. In general, thermal burns and frostbite injuries should be managed nonoperatively until the extent of the damage can be assessed accurately and the amputation can be performed at the most distal level consistent with good healing. Pyrophosphate nuclear scanning has been demonstrated to be useful in predicting the need for amputation in these situations.[13]

Even in the trauma setting, the level of amputation may be difficult to determine. Most cases of trauma involve significant avulsion and crush components that leave obvious devitalized tissue exposed. The complete extent of the injury zone may not be apparent on initial presentation. When in doubt, especially in grossly contaminated wounds, it is wise to proceed with open amputation to allow the wound to declare itself prior to closure over a definitive stump length.

Neglected compartment syndromes in the upper extremities commonly necessitate amputation. Initially, fasciotomies are performed, and provided that the patient remains systemically stable, initial debridement should remove tissue that is obviously dead. Tissue that is neither contractile nor bleeding should be removed at this time. Tissue that is noncontractile but bleeding and that otherwise appears to be healthy should be left intact; fasciotomies should be left open and have a sterile dressing that prevents desiccation.

The patient should then return to the operating room within 24-48 hours for a second observation of the tissues, and the tissues should be debrided as described above. This conservative process continues until the tissues have stabilized and the surgeon is convinced that all remaining tissue is viable. Although this stepwise conservative debridement is labor-intensive, it ensures that the absolute minimal tissue has been removed and that the patient is left with maximal function.

Even in severe instances where amputation is indicated, this stepwise process dictates the level of amputation and ensures maximum length for the remaining portion of the extremity; otherwise, an arbitrary guess at the amputation level may be necessary, possibly leaving the remainder of the extremity inappropriately long (resulting in failure of healing) or inappropriately short (resulting in decreased functional potential). However, the stepwise process is contraindicated in patients with systemic sepsis, renal compromise secondary to disseminated myoglobin, or some other critical illness that leaves the patient unable to sustain multiple surgeries.

Laboratory studies

Hematocrit and hemoglobin levels should be monitored. In trauma situations, acute blood loss is a concern. Even with elective amputations, postoperative bleeding and hematoma formation require careful assessment. Acceptable levels are individualized on the basis of age, associated medical problems and injuries, and baseline values. In general, a young, otherwise healthy patient should maintain a hematocrit above 20% and a hemoglobin level higher than 6 g/dL. Elderly patients or patients with underlying cardiovascular disease should be maintained at higher levels (30% and 10 g/dL).

Creatinine levels should be monitored. In individuals with muscle injury and necrosis, myoglobin enters the systemic circulation and can lead to renal insufficiency and failure. This is especially true in individuals with thermal and electrical burns. If creatinine levels continue to rise more than 0.4 over baseline, preoperative, or preinjury levels, more aggressive surgical intervention and fluid hydration should be considered.

Potassium and calcium levels should be monitored. As dead tissue is metabolized, destroyed cells release intracellular stores of potassium and calcium into the extracellular space. Elevated levels of these electrolytes may lead to cardiac arrhythmias and seizures.

The white blood cell (WBC) count, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) should be monitored in persons with infection. It is helpful to observe that these values normalize following amputation, thus suggesting resolution of the infection. The laboratory CRP value is typically the first to respond to treatment; the other two may take several days to weeks to normalize despite eradication of the infection. If these values remain elevated or rise further, treatment should be reassessed by changing to a more appropriate antibiotic, by searching for an unrelated occult infection or hidden abscess, and possibly by performing revision amputation at a more proximal level.

Platelets should be monitored periodically if subcutaneous heparin is administered postoperatively. Heparin-induced thrombocytopenia may occur even as a result of small subcutaneous doses of heparin.

Imaging studies

Plain radiography should be routinely included in preoperative planning. The presence of hardware, occult pathology, or other unanticipated abnormalities in an extremity to be amputated may affect the surgical plan.

In oncology cases, preoperative computed tomography (CT) and magnetic resonance imaging (MRI) have proved invaluable in assessing the extent of tumor involvement and level of amputation. When a forequarter amputation is considered in the treatment of a malignancy, CT and MRI should include not only the affected extremity but also the lungs. Occasionally, preoperative CT or MRI is helpful in evaluating the extent of infection and abscess in these particular settings.

Arteriography remains the standard for the definitive analysis of vascular status. However, because this is an invasive procedure, arteriography carries the risk of leading to a pseudoaneurysm, hematoma, and vascular embolism in the patient.

MRA remains a noninvasive alternative to arteriography. It avoids the complications of arterial puncture, eliminates the risk of contrast-related renal failure, and has a higher sensitivity than does contrast angiography in the identification of severe peripheral arterial occlusive disease.

Pyrophosphate nuclear scanning has been introduced as another noninvasive method of evaluating tissue viability. It has been demonstrated to be a useful adjunct in predicting the need for amputation in persons whose extremities have been damaged by electrical injury, frostbite, or invasive infection. Pyrophosphate nuclear scanning has a sensitivity of 94%, a specificity of 100%, and an accuracy of 96% when performed for this purpose.

Doppler ultrasonography (US) detects blood flow, and when employed in conjunction with blood pressure cuffs, it can be used to measure arterial pressure at different levels in the upper extremity.

Other studies

Transcutaneous oxygen tensions reflect tissue perfusion. Significant occlusive disease causes these measurements to fall below 35 mm Hg. In considering the level of amputation, it is imperative that transcutaneous oxygen tensions at the level of incision be at least 35 mm Hg, because measurements below this level are associated with decreased healing and wound problems. Measurement of tissue oxygen tension is not affected by incompressible, calcified vessels and appears to be very sensitive in evaluating arterial occlusive disease during exercise.

The time for prosthetic fitting in a person with an upper-extremity amputation has been debated. Traditionally, fitting commences once stump shrinkage has subsided, usually after 8-12 weeks. However, many have advocated immediate or early prosthetic fitting to improve outcome, particularly with regard to early bimanual activities and user rates.

Malone et al described a "golden period" of prosthetic fitting, which occurs within the first month following amputation of the upper extremity; according to the authors, fitting during this period maximizes prosthetic acceptance rates and use patterns among patients, regardless of the type of prosthesis that is initially employed.[14]

Malone et al also observed that if the fitting occurred within this time, patients demonstrated decreased edema, decreased postoperative pain, decreased phantom pain, accelerated wound healing, improved rehabilitation, and decreased hospital stays, compared with patients who underwent later fittings.[14] These benefits were less pronounced at amputation levels above the elbow but were still significant.

Unlike patients with a lower-extremity amputation, most persons with an upper-extremity amputation have excellent vascularity in their stump and are much less prone to wound-related problems. It appears that in the upper extremities, the advantages of immediate or early prosthetic fitting far outweigh the disadvantages.

Elbow disarticulation

When the elbow joint must be sacrificed, an elbow disarticulation is preferable to a more proximal amputation. Not only is greater length preserved, but also the broad flare of the remaining humeral condyles enhances prosthetic fitting and allows humeral rotation to be transmitted to the prosthesis.

Equal anterior and posterior skin flaps are created, beginning at the level of the humeral epicondyles. The incisions are extended distally 3 cm distal to the tip of the olecranon posteriorly and to a point just distal to the insertion of the biceps tendon anteriorly. The lacertus fibrosus is identified and divided, which allows the flexor-pronator origin to be freed from the medial epicondyle and exposes the neurovascular bundle underneath.

The brachial artery is isolated, doubly ligated, and divided proximal to the joint line. Located medial to the brachial artery, the median nerve is drawn distally, transected as proximally as possible, and allowed to retract into the proximal wound.

The ulnar nerve is identified posterior to the medial epicondyle and is transected in a similar manner. The biceps and brachialis tendons are freed from their insertions on the radius and ulna, respectively. Within the interval between the brachialis and brachioradialis, the radial nerve is identified and transected (as above).

The extensor musculature is divided transversely, approximately 7 cm distal to the joint line. Although the skin flaps are approximately equal, the posterior muscle flap remains longer than the anterior muscle flap so that it can wrap around and cushion the end of the humerus.

To complete the disarticulation, the anterior capsule and posterior fascia near the level of the olecranon tip are divided, the radiohumeral and ulnohumeral capsules are divided posteriorly, and the forearm is removed. The articular surface of the humerus is left intact.

The posterior flap should be carried medially and anchored to the remaining soft tissues on the medial epicondyle. Additional sutures are placed through the muscle flap and adjacent periosteum, so that all bony prominences and exposed tendons at the end of the humerus are covered. In patients with very little subcutaneous tissue and muscle, covering the end of the humerus with a reflected flap of brachialis, biceps, or triceps may be advisable.

Because of the flare of the humeral condyles, the distal stump should be expected to be somewhat more bulbous than it is for amputations above the elbow.

An article from Brazil suggested a surgical procedure by which electric elbow prostheses are fitted to an elbow disarticulation.[15] Normally, the bulky motor hangs several centimeters below the contralateral elbow, causing a cosmetic problem. The authors suggested a shortening osteotomy through the supracondylar area, thus accommodating the prosthetic motor and preserving the condylar flares.

Transcondylar amputations

Amputations at this level function prosthetically as elbow disarticulations. Depending on the precise level, some portion of the lateral epicondyle with its attached posterior flap may be preserved. If the lateral epicondyle and posterior flap are otherwise compromised, closure over the humerus must be accomplished by means of techniques described for amputations at the supracondylar level (see Above-Elbow Amputations below). However, this coverage should not affect the prosthetic function as long as some remnant of the condylar flare is preserved.

Supracondylar amputations

Amputations at or proximal to the supracondylar level define the distal extent of above-elbow amputations. Amputations distal to the supracondylar area, such as the transcondylar amputation, function as elbow disarticulations and are prosthetically fitted as such (see Elbow Amputations above). Without the presence of the humeral condylar flare, the prosthesis must contain an elbow-lock mechanism and an elbow turntable to allow prosthetic joint stability and rotation, respectively.

As with all amputations, length should be preserved as much as possible. However, the necessary prosthetic elbow-lock mechanism extends approximately 4 cm distally from the end of the prosthetic socket and, to be cosmetically appealing, should lie at a level equal to that of the contralateral elbow. Therefore, bone sectioning at the supracondylar level and above should be at least 4 cm proximal to the elbow joint to allow room for this mechanism.

Anterior and posterior skin flaps are extended equally. Neurovascular structures are identified and are divided as described for elbow disarticulations. Muscles in the anterior compartment of the arm are transected 2 cm distal to the intended level of bone section. The triceps insertion is freed from the olecranon, with the triceps fascia and muscle preserved as a long flap.

The humerus is sectioned at least 4 cm from the joint to allow for the prosthetic elbow mechanism. After the contour of the humeral end is smoothed with a rasp, the triceps flap is carried anteriorly and sutured to the fascia of the anterior muscular compartment.

Transhumeral amputations proximal to supracondylar area

Amputations that are proximal to the supracondylar area should maintain all possible length. In traumatic amputations, it should be considered whether free-flap coverage and skin-graft coverage are possible alternatives before the choice of additional bone resections to allow primary closure.

Skin and muscle flaps are fashioned as previously described. Neurovascular bundles are isolated and transected in order to retract into the proximal stump. The anterior and posterior fascias over the flexor and extensor muscle masses are sutured together to cover the end of the humerus. It may be necessary to trim some of the muscle fibers to decrease bulk and better contour the final stump. Alternatively, closure may be accomplished in two layers, with the subcutaneous tissue and skin used to contour the end of the stump.

Transhumeral amputations at or above the level of the pectoralis major insertion deserve special consideration. Bony resection through the level of the surgical neck functions as a shoulder disarticulation because independent motion of the humerus is no longer possible. However, preservation of the humeral head retains the normal contour of the shoulder, which is cosmetically desirable. Furthermore, the stability of a disarticulation prosthesis is enhanced if a portion of the humerus remains.

The technique of amputating through the surgical neck involves placing the patient in a position that allows access to the anterior and posterior shoulder. "Beach-chair" or "sloppy" lateral decubitus positions are commonly used. The incision begins at the coracoid and follows the inferior border of the anterior and posterior deltoid to its insertion laterally. Crossing the axilla with an additional incision connects the two limbs of the incision.

The cephalic vein is identified within the deltopectoral groove and divided proximally. The deltoid and the pectoralis major are freed from their insertions at the humerus. The plane between the coracobrachialis and the pectoralis minor is developed. The pectoralis minor is left attached to the coracoid, and the coracobrachialis is removed from its origin, revealing the neurovascular bundle underneath. The axillary artery, as well as the radial, median, ulnar, and musculocutaneous nerves, should be isolated and divided so that they retract deep to the pectoralis minor.

The lateral flap of the deltoid is developed from the humerus. The axillary nerve on the undersurface of the deltoid must remain intact during this dissection. If this nerve is injured, atrophy caused by denervation of the deltoid compromises stump cushion and prosthetic fit.

Near their insertions at the bicipital groove, the teres major and the latissimus dorsi should be divided. The long and short heads of the biceps, triceps, and coracobrachialis are divided approximately 2 cm distal to the level of intended bony section. After the humerus is cut and rounded, the long head of the triceps, the two heads of the biceps, and the coracobrachialis are sutured together as a myofascial flap over the end of the humerus.

Alternatively, both heads of the biceps may be divided and allowed to retract proximally into the stump. In either alternative, the pectoralis major is advanced laterally and secured to the end of the humerus. The deltoid flap covers the remaining bone and is sutured to the skin of the axilla. Some contouring of the deltoid flap may be necessary to ensure proper skin approximation.

Shoulder disarticulation

Disarticulations at the shoulder level severely hinder prosthetic function because virtually all shoulder motion is lost. In fact, the prosthesis is used primarily as a holding device when the patient is performing activities with both hands. As previously explained, sparing the humeral head is preferable whenever possible to obtain the best appearance and prosthetic fit.

Shoulder disarticulation is performed in a manner similar to that described for amputations at the level of the pectoralis major, with a few notable exceptions. After ligation and division of the axillary artery, the thoracoacromial artery can be identified just at the medial border of the pectoralis minor tendon, where it emerges from the second portion of the axillary artery. From this artery, the acromial branch may be observed lying on the pectoralis minor tendon and coursing toward the acromion. This vessel should be ligated and allowed to retract.

By placing the arm in extreme internal rotation, the short external rotator muscles and the posterior capsule are exposed and easily sectioned. Placing the arm in extreme external rotation facilitates division of the anterior capsule and the subscapularis. After excision of the humeral head, the cut ends of all muscles are reflected and secured into the glenoid cavity in an effort to fill the resulting hollow. Finally, partial excision of the acromion may be necessary to smooth the contour of the shoulder.

Forequarter amputations

A forequarter amputation (FQA), also referred to as a shoulder girdle or interscapulothoracic amputation, removes the entire upper extremity and shoulder girdle in the interval between the scapula and thoracic wall. This operation is reserved for malignant tumors that extend to the region of the shoulder joint or infiltrate the deltoid, pectoral, or subscapular muscles.[16]  The functional prognosis is poor following this procedure, and the 5-year survival rate for patients was reported to be only 23%, presumably because of the grave circumstances that warrant such a radical procedure.[11]

Two techniques have been described. The classic anterior approach introduced by Berger involves ligating the major vessels as the preliminary step.[17]  Littlewood described a posterior approach, which is regarded by most as somewhat less technically demanding.[18]

The anterior approach begins with the upper limb of the incision, which starts at the lateral border of the sternocleidomastoid, extends laterally along the anterior aspect of the clavicle and across the acromioclavicular joint and the superior aspect of the shoulder to the scapular spine, and then progresses inferiorly along the vertical border of the scapula to the scapular angle. The lower limb of the incision begins at the middle third of the clavicle, extends along the deltopectoral groove, and continues across the axilla to connect to the upper limb of the incision at the angle of the scapula.

Reflect the clavicular portion of the pectoralis major, and expose the entire clavicle. Retract the external jugular vein from the field, or section the vein if it remains in the way. With a saw, divide the clavicle at the lateral border of the sternocleidomastoid and remove the bone by disarticulating the acromioclavicular joint. The subclavian muscle is divided medially. Releasing the insertions of the pectoralis major from the humerus and the pectoralis minor from the coracoid process exposes the subclavian artery and vein for double ligation and division. The brachial plexus is gently pulled distally into the field and sectioned to allow retraction superiorly.

The latissimus dorsi and remaining soft tissues that bind the shoulder girdle anteriorly to the chest wall are divided, followed by the muscles that hold the scapula to the thorax. Begin by dividing the trapezius, and continue through the omohyoid, levator scapulae, rhomboid major and minor, and serratus anterior. The limb is then removed. For additional padding, the pectoralis major, the trapezius, and any other remaining muscular structures may be sutured over the lateral chest wall. Given the circumstances under which this procedure is required, atypical flaps and skin grafts are often used, which may complicate closure.

The more popular posterior approach has the advantage of easily mobilizing the limb before the more challenging anterior dissection to gain vascular control. The approach involves two incisions. The first, which is the posterior cervicoscapular incision, begins at the medial end of the clavicle, extends laterally for its entire length, proceeds over the acromion to the posterior axillary fold, and then continues along the axillary border of the scapula to the scapular angle, where it curves medially to end 5 cm from the midline of the back.

The trapezius and the latissimus dorsi are divided parallel with the scapula. The levator scapulae, the rhomboids, and the scapular attachments of the serratus anterior and omohyoid are divided. Careful cauterization of the branches from the transverse cervical and transverse scapular arteries is warranted. The subclavian muscle is divided medially, as is the clavicle lateral to the insertion of the sternocleidomastoid. The extremity is then allowed to fall anteriorly, thus exposing the subclavian vessels and brachial plexus for relatively easy division.

The second incision, which is the anterior pectoroaxillary incision, begins at the middle of the clavicle and then curves laterally to the deltopectoral groove and toward the axillary fold, where it joins the posterior axillary incision at the lower axillary border of the scapula. Finally, the pectoralis major and minor are divided, and the limb is removed.

Radical forequarter amputation

Roth et al described a radical FQA that includes the chest wall.[19]  Indications for this procedure are extensive tumors that involve the shoulder girdle, chest wall, or axilla. Thoracic surgeons are usually involved with this type of procedure.

Tikhoff-Linberg procedure

In rare instances, such as when well-localized tumors of limited extent are present, resection of the shoulder girdle with preservation of the arm may be indicated. When it is feasible, this procedure is preferable to the more disfiguring FQA, because the Tikhoff-Linberg procedure preserves some distal extremity function.

The anterior and posterior portions of the technique are similar to those of the FQA described by Berger. However, the humerus is transected at the appropriate level and the proximal portion is removed. Once the shoulder girdle is excised, it may be possible to reattach some of the remaining arm musculature proximally, either to the rib cage or to the soft-tissue attachments about the hemithorax.

A variation of the Tikhoff-Linberg procedure is to perform a partial or complete scapulectomy, leaving the humerus intact. One study reviewed 12 patients undergoing complete scapulectomies for malignancies.[20]  At 6 months, there were no deaths and no local or regional recurrences. The authors concluded that scapulectomy remains an excellent procedure for local tumor control with preservation of distal limb function, though follow-up care was short for some patients and residual function was not defined clearly.

A soft compressive dressing is applied to the stump. The elastic bandage is applied more tightly distally than proximally to prevent stump edema. Rigid dressings and casts, such as those often used on lower-extremity stumps, are unnecessary for the upper extremity. If a drain is placed, it is removed within 24-48 hours. Provided that no contraindications exist for anticoagulation, low-dose subcutaneous heparin (5000 U q12hr) may be administered for deep venous thrombosis (DVT) prophylaxis, especially in the case of high-risk patients. Immediate active range of motion (ROM) of the shoulder, if applicable, is implemented to prevent joint contractures.

Hematoma

Meticulous hemostasis and, if necessary, the use of a drain can minimize the occurrence of postoperative hematomas. If allowed to accumulate, hematomas may provide an attractive medium for bacteria and may inhibit proper wound healing. Aspiration of the hematoma under sterile conditions is recommended, followed by the use of a compressive dressing to reduce the recurrence rate. If hematoma accumulation persists, surgical exploration, instead of resorting to repeat aspirations, may be required to achieve adequate hemostasis.

Infection

Upper-extremity amputation stump infections are more likely to occur in patients who are immunocompromised or who have previous vascular diseases, as well as in patients with grossly contaminated or infected wounds. As with any postoperative infection, superficial infections may be treated with proper wound care, antibiotics, and close observation, but deep infections, whether accompanied by an abscess or not, may require further surgical débridement and possibly revision amputation to a more proximal level. It has been suggested that delaying formal amputation closure for at least 5 days after the procedure may reduce the rate of postoperative infection.[21]

Necrosis

As with infections, superficial areas of skin necrosis may be treated conservatively because healing usually continues under the eschar. However, larger areas of necrosis indicate insufficient vascularization and demand resection or possibly revision amputation to a more proximal level.

Neuroma

Regardless of the technique employed to divide peripheral nerves, a neuroma always forms. If the neuroma is compressed against a rigid surface (eg, a bone or a prosthetic wall) or if the neuroma experiences traction as it remains trapped in the healing scar, pain inevitably occurs.

Efforts to prevent the compression or entrapment of neuromas have previously been described. When a neuroma becomes symptomatic, it can usually be treated by altering the prosthetic socket so that pressure or traction on the lesion is avoided. When all nonoperative efforts have failed to relieve pain, the neuroma may be successfully excised, and the nerve can be divided at a more proximal level. In children, neuromas seldom warrant surgical intervention.

Phantom sensation

This poorly understood phenomenon is defined as the patient's awareness of the amputated portion of the limb.[22, 23, 24] The sensations may be disturbing but are rarely painful.

Many modalities have been used in an attempt to prevent or minimize the intensity of the sensations. Amitriptyline and gabapentin can be considered first-line agents in the pharmacologic treatment of phantom sensations. Other agents used less commonly are capsaicin, calcitonin, mexiletine, carbamazepine, propranolol, metoprolol, and clonazepam. Many of these drugs have only case-report usage and require further investigation.

Promising therapies for the upper extremity have included immediate or early prosthetic fitting. Substantial evidence also exists to support the use of perioperative epidural anesthesia and postoperative intraneural anesthesia that, though normally applied to transected nerves in amputated lower extremities, may be effective in the upper extremities. However, such data for the upper extremities are not yet available. Phantom sensations are uncommon in children.

Deep venous thrombosis

Patients who have undergone amputation may be at increased risk for DVT. Although persons with upper-extremity amputations are able to mobilize more easily after surgery than those with lower-extremity amputations (and consequently present less often with DVT), their underlying medical conditions often predispose them to this complication. This is because of multiple risk factors for DVT in this population, such as age, some degree of immobility, and the amputation itself, which involves the ligation of vessels.

Furthermore, 25% of patients undergoing vascular surgery have an identifiable hypercoagulable state. Unfortunately, most data pertain to individuals with lower-extremity amputations; therefore, it is difficult to make conclusions about the risks for persons with upper-extremity amputations.

Nevertheless, it is advisable to administer low-dose subcutaneous heparin to patients who have undergone amputations while they are still in the hospital, provided that they have no contraindications to anticoagulation. Low-molecular-weight heparins (LMWHs), such as enoxaparin and dalteparin, may increase the risk of bleeding and hematoma formation and may induce more anticoagulation than is necessary in the upper extremity. However, further research is required to assess the risks and benefits of anticoagulation therapy in this setting.

Terminal overgrowth

Although many amputation complications, such as neuroma or phantom pain, are less problematic in children, terminal overgrowth occurs to some degree in all children with amputations; as many as 12% of children with amputations require one or more stump revisions.

Above-elbow amputations are more problematic in this regard than any other amputation because the humerus is most commonly associated with this phenomenon. In above-elbow amputations, the humerus frequently overgrows distally and often with varus angulation. The cause of overgrowth is still controversial. Contracture of the soft-tissue envelope and disproportionate growth of bone from the proximal physis to the soft tissue have been implicated. However, a current hypothesis points to malfunctioning and acceleration of established mechanisms of normal fracture healing and local wound healing.[25]

Pediatric patients with disarticulations do not demonstrate terminal overgrowth, because the articular cartilage acts as a natural barrier to this activity. For this reason, as well as to preserve the distal physis and maintain normal stump growth, disarticulations are the treatment of choice in children whenever possible. Most attempts to prevent terminal overgrowth, including capping the bony ends with Silastic or with allograft and autograft tissues, have failed. The only treatment for symptomatic terminal overgrowth is revision amputation.

Bony spur

Bony spurs occasionally form at the end of the bones, especially in children. Unlike terminal overgrowth, bony spurs almost never require resection and are well tolerated after prosthetic socket modifications.

Contracture

Shoulder contractures are usually prevented with immediate postoperative active motion, when applicable. If contractures develop, more aggressive physical therapy may be required, including strengthening of the opposing musculature and the use of gentle passive motion.