Upper extremity amputation

INTRODUCTION — Upper extremity amputation is most often performed to treat a traumatic injury. Extremity amputation may also be necessary to treat malignancy or to manage refractory pain or a congenital deformity.

Microsurgery, reconstructive surgery, and replantation have become established treatments for trauma and malignancy. However, for those in poor general condition or who have experienced prolonged ischemia after a traumatic injury, amputation may be the best option and is frequently necessary in the context of damage control surgery. The loss of upper extremity function resulting from an amputation can be reasonably ameliorated with the use of an upper extremity prosthesis.

The indications, surgical procedures, and outcomes of upper extremity amputation are reviewed here. Amputation of the lower extremity is reviewed separately. (See "Lower extremity amputation".)

EPIDEMIOLOGY — Upper extremity amputation in adults may be required as a result of trauma, ischemia, infection, or malignancy. More than 500,000 people were living with upper extremity amputation in 2005, and upper extremity amputations accounted for one-third of all amputations [1]. Of these, approximately 8 percent were major amputations, which is defined as amputation proximal to the wrist joint (figure 1).

Trauma is the leading cause of amputation of the upper extremities [1]. Work-related injuries predominate among civilians while improvised explosive devices (IEDs) are the main cause among military personnel. Operation Iraqi Freedom reported the proportion of combat-related upper extremity amputations to be as high as 50 percent of all amputations; however, this rate has decreased to less than 20 percent because of improvements in protective gear [2,3].

Finger amputations account for a large portion of traumatic amputations. Between 2002 and 2010, the National Electronic Injury Surveillance System estimated over 200,000 emergency room visits for finger amputations in the United States. Although overall finger amputation rates remained almost unchanged, work-related finger amputation rates decreased by 40 percent [4]. Similarly, a study from South Korea reported a decrease in labor-related finger amputations between 2004 and 2013 [5].

Although severe ischemia leading to nonhealing ulcers or gangrene due to peripheral artery disease is a leading cause of lower extremity amputation, this is an uncommon cause in the upper extremity, primarily because of the extensive collateral circulation (figure 2) around the shoulder and elbow [1]. (See 'Ischemia' below and "Upper extremity atherosclerotic disease".)

INDICATIONS

Extremity trauma — With traumatic amputations, replantation may be attempted, but in cases of replantation failure, a revision amputation is performed as a final treatment option (picture 1). Traumatic amputations, in the absence of a replantation attempt, may also require revision. (See 'Replantation versus completion amputation' below.)

If reconstructive options are limited, severe injury (ie, mangled extremity, crush injury) may require amputation. In these situations, it is necessary to make a reasonable judgment whether to perform a primary or revision amputation, or attempt reconstruction. (See "Severe lower extremity injury in the adult patient", section on 'Management approach'.)

For severe brachial plexus injuries, it may be more prudent to perform amputation to remove an insensate, nonfunctional arm and to fit a patient with a prosthesis (picture 2) [6]. Moreover, amputation combined with shoulder arthrodesis can stabilize the shoulder joint, leading to improved pain management and greater patient satisfaction [7].

Ischemia — The proportion of ischemic diseases occurring in the upper extremities is much lower compared with the lower extremities, and upper extremity ischemia rarely becomes symptomatic [8]. Upper extremity atherosclerotic disease is uncommon, and upper extremity ischemia is more often associated with arterial embolism, trauma, connective tissue disease, and dialysis access-related steal syndrome [9,10]. Severe and prolonged spasm of the small artery in fingers and hands can also cause ischemia and result in necrosis of the fingers [11]. (See "Embolism to the upper extremities".)

Most ischemic diseases occurring in the upper limbs are relieved by measures that improve perfusion (eg, stenting), such as removing inciting factors (eg, smoking cessation, hand warming) and optimizing local wound care, including antibiotic therapy as needed.

Amputations are only performed in severe situations, such as when necrosis or gangrene is complete and irreversible (picture 3). If an infection occurs with gangrene, the probability of needing an amputation increases.

Infection — Patients with diabetes or immunodeficiency are more susceptible to diseases that can cause infection and lead to possible upper extremity amputation. In one retrospective review of 46 patients with upper extremity infections who had undergone surgical treatment, approximately one-half of them underwent multiple operations, and 18 eventually required an amputation [12]. Deep infection with anaerobic bacteria in patients with diabetes resulted in a high probability of subsequent limb amputation [12]. (See "Overview of hand infections".)

Necrotizing fasciitis is a life-threatening disease that can occur in patients with recent surgery or in association with open wounds, obesity, diabetes, liver disease, or immunodeficiency. It occurs more commonly in the lower extremities but can also occur in the upper limbs, which are affected in 20 to 40 percent of cases [13]. Vibrio vulnificus is more commonly associated with the upper extremities [14-16]. Surgical debridement and reconstruction are usually all that is necessary, but the possibility of immediate amputation increases when the disease is accompanied by diabetes or sepsis [17]. Mortality increases when necrotizing fasciitis is accompanied by liver cirrhosis or chronic heart disease [18]. (See "Necrotizing soft tissue infections" and "Vibrio vulnificus infection".)

Malignancy — Osteosarcoma and many soft tissue sarcomas occur in the extremities, and most of them are treated with a combination of a wide excision and radiotherapy, and reconstruction. Proximal, large, high-grade, or recurrent tumors sometimes necessitate an amputation [19,20]. (See "Overview of multimodality treatment for primary soft tissue sarcoma of the extremities and superficial trunk" and "Surgical reconstruction of the upper extremity".)

Pediatric — Pediatric amputations are divided into two categories: congenital and acquired.

Congenital limb deficiency or deformity — Limb deficiencies (ie, congenital amputation) of the upper extremities occur 1 to 2 per 1000 live births in the United States [21].

The upper extremity is involved in 58.5 percent of congenital limb deficiency. The causes of congenital amputation are not completely understood, but they are thought to be influenced by genetic and environmental factors. Environmental factors include drug or alcohol abuse, infections, exposure to chemicals, or the use of medications like thalidomide during pregnancy [22]. Many digit or limb deficiencies are caused by the failure of its formation or the arrest of its development. Depending on its morphological features, the deficiency is divided into either longitudinal or transverse deficiencies. The most common congenital deficiency in the upper extremities is a longitudinal hand deficiency [21]. Rarely, amniotic band constriction results in the amputations of digits and limbs, and it is one of the symptoms of constriction band syndrome. (See "Congenital anomalies: Causes" and "Congenital anomalies: Epidemiology, types, and patterns" and "Amniotic band sequence".)

Congenital deformities that may require amputation include mirror hand or polydactyly, and severe hemangioma. Some congenital limb deficiency cases may require revisional amputation to fit the prosthesis, but it is rarely performed (about 10 percent of patients) [23].

Acquired — Acquired amputations in children are needed for some of the same reasons as in adults such as for trauma, malignancy, or severe infection.

UPPER EXTREMITY ANATOMY

Shoulder girdle — The shoulder joint is classified as the ball and socket joint and is vulnerable to outer forces, causing dislocation of the joint. Several muscles, such as the pectoralis major muscle, deltoid muscle, and trapezius muscle, surround the shoulder joint and stabilize it. In addition, the rotator cuff contributes to stabilization of the shoulder joint. Thus, in revisional shoulder disarticulation or forequarter amputation, coverage of the stump is facilitated by the presence of sufficient soft tissues.

The neurovascular bundle to the upper extremity is derived from the cervical spine to form the brachial plexus posterior to the clavicle (figure 3). Vessels and nerves descend together to the brachium (figure 4).

Brachium and elbow joint — The brachium consists of two muscular compartments. The anterior compartment is composed of the flexor of the elbow joint, and all muscles in it are dominated by the musculocutaneous nerve (figure 4). The posterior compartment is mainly occupied with the triceps. All the nerves to the upper extremity stay together in the brachial plexus, and the median nerve and the ulnar nerve descend in the medial side of the anterior compartment with the brachial artery (figure 5 and figure 6). The radial nerve descends down the arm, wrapping around the humerus laterally, and is accompanied by the deep branch of the brachial artery (figure 7).

The elbow joint is stabilized by extrinsic muscles and the collateral ligaments. The most important stabilizer is the lateral ulnar collateral ligament sustaining the proximal part of the radius and preventing posterolateral rotatory instability. For forearm amputations that preserve the function of the elbow, surgeons should take care to preserve the anatomy of such stabilizers.

Forearm and wrist joint — There are many muscles in the forearm, and most muscles originated from the forearm are inserted into the digit bones or carpal bones functioning as sources of the motion of digits and the hand (figure 8).

The forearm has three muscular compartments (figure 8). In the volar compartment, there are flexor and pronator muscles, with the median and ulnar nerves and the radial and ulnar arteries occupying more than half of the transverse diameter of the forearm. The dorsal compartment contains the extensor muscles. The third compartment is referred to as the mobile wad, including the brachioradialis, extensor carpi radialis brevis, extensor carpi radialis longus muscles, and superficial branch of the radial nerve.

The wrist joint consists of the radiocarpal joint and the midcarpal joint. The motion of the organized eight carpal bones creates various motions of the wrist and forearm. Because of the complex morphology of the carpal bones, amputation of the wrist joint is usually performed in the radiocarpal joint.

Hand and fingers — The hand has eight carpal bones and five metacarpal bones (figure 9) surrounded by the interosseous, thenar, and hypothenar muscles (figure 10). The median nerve passes through the carpal tunnel and separates the thenar branch, innervating several thenar muscles. After that, it provides sensation for the radial three fingers and radial half of the ring finger. The ulnar nerve accompanied by the ulnar artery (figure 11) in the forearm divides into three branches, and all branches go through the Guyon canal. Its motor branch innervates several interosseous muscles and ends in the adductor muscles of the thumb.

The radial artery divides into two branches proximal to the wrist joint, and each of these arteries makes a connection with those of the ulnar artery to form the arterial arches.

The fingers and thumb do not have muscles, with each phalanx mainly surrounded by tendons and aponeuroses (figure 12). Each digit has two main arteries and two digital nerves in the volar side surrounded by the Cleland and Grayson ligaments.

TYPES OF UPPER EXTREMITY AMPUTATIONS — Amputations are classified based upon the level of amputation (figure 1) [24]. Major amputation is defined as amputation proximal to the wrist joint; minor amputations involve the hand and digits. (See 'Level of surgical amputation' below.)

Minor amputations:

●Digit: Transphalangeal, finger disarticulation

●Hand: Transmetacarpal, transcarpal, wrist articulation

Major amputations:

●Forearm: Transradial

●Elbow disarticulation

●Above elbow: Transhumerus

●Shoulder disarticulation

●Forequarter amputation

UPPER EXTREMITY TRAUMA MANAGEMENT — The initial care and management of the trauma patient is according to the American College of Surgeons Advanced Trauma Life Support. (See "Severe lower extremity injury in the adult patient", section on 'Initial evaluation and management'.)

When there is a possibility for replantation, the amputated portion of the upper extremity should be wrapped in gauze and soaked in sterilized isotonic saline to prevent it from drying. In addition, it should be placed in a plastic bag that is immersed in ice water for cooling. An amputated extremity should never be placed directly in ice water because the infiltration of fluid into the part may jeopardize the microcirculation. (See "Severe lower extremity injury in the adult patient".)

Replantation versus completion amputation

Major amputation — For most major amputations, replantation should be attempted, when possible. Patients and their families or other caregivers must recognize that the patient will never return to their previous normal state regardless of the decision to replant or amputate the affected limb [25]. In a retrospective review of litigation during 10 years in a major replantation center, the majority of cases were filed over a decision not to replant [26]. In cases where confident judgment is not possible, phone consultation with an experienced surgeon can be effective to render a suitable decision whether to replant [27,28].

Crush injuries, multilevel amputations, and most distal amputations are not candidates for replantation because of low rates of success. Traumatic upper extremity amputations in the face of prolonged ischemia (>6 hours) are not replanted [29]. In the hemodynamically unstable patient with other serious injuries, damage control surgery takes precedence and replantation may not be an option. In rare cases of proximal upper extremity injury with massive bleeding, an immediate revision amputation may be necessary to control hemorrhage and may be lifesaving. Replantation should also be avoided if the patient is not willing to undergo multiple surgical treatments or is unlikely to be able to participate in postoperative rehabilitation after surgery.

When major traumatic amputation has occurred, replantation is usually attempted first given generally better reported outcomes compared with amputation and prosthesis (picture 4) [30-32]. However, for some cases of traumatic upper extremity amputations, a revision amputation and a prosthesis can lead to greater recovery of function than a replantation. In a review comparing replantation (or reconstruction by use of residual tissue and tissue transplantation) with revision amputation and a prosthesis, patients undergoing reconstruction scored significantly higher on all patient-related outcomes [30]. In another comparative study of traumatic amputation, one half of the patients with replantations at the distal elbow had better results than the patients who received a revision amputation [31]. In one review, all patients stated that they would undergo replantation again if they had the same injury [32].

Minor amputation — Approximately 90 percent of traumatic amputation are minor and finger amputations [33]. The rate of finger amputation decreased by 50 percent from 2000 to 2011 [4]. Finger amputation can be treated by replantation or revision amputation. Similarly, amputation of the thumb or multiple fingers can be treated with replantation [4]. A retrospective, multicenter study found that replantation was the more cost-effective option for single, thumb, and multiple finger amputations in certain settings [34]. Patients who were active participants in their hand physiotherapy were able to return to work sooner, thus increasing their postoperative income and the overall cost-effectiveness of replantation [34]. The generally accepted indications for replantation of minor upper extremity amputations are listed below [35].

●Thumb amputation – Thumb replantation has better functional outcomes than any prosthesis, making replantation a priority.

●Multiple digit amputations – Emphasis should be placed on replanting the middle finger and thumb to restore the ability to pinch.

●Midpalm amputation – Replantation should be attempted because good functional recovery can be expected.

●Pediatric amputations – Amputations in children are generally an indication for replantation.

●Single-digit amputation – An amputated finger in the distal region of the flexor digitorum superficialis attachment section should be considered for replantation because the function of the proximal interphalangeal joint is not disturbed by the replantation [36]. However, replantation in the proximal phalanx, which has little movement of the injured finger, sometimes disturbs the movement of other fingers, so the indication of replantation is uncertain [37,38].

EVALUATION AND PREPARATION — Decision making is primarily based upon clinical examination. Angiography (computed tomography [CT], magnetic resonance [MR], catheter based) is sometimes used to aid in deciding the level of amputation during preoperative planning but is generally not needed.

Level of surgical amputation — The site of the injury or lesion has a significant impact on prosthesis use and other postoperative functions. The length of the residual extremity should be left as long as possible to maximize the range of motion. With forearm amputation, the range of pronation-supination is proportional to length of the forearm. A stump longer than 7 cm is desirable [39,40].

To preserve length, reconstruction options (skin grafting, flap, free tissue transfer) should be considered rather than shortening the bone. If a large amount of soft tissue is lost following trauma or resection of a tumor, free tissue transfer to maintain the length of the upper extremities should be considered [40]. Free tissue transfer with a concurrent amputation has a complication rate as high as 38 percent but has greater success in the preservation of the stump length [40]. If such transfer is not possible, a more proximal amputation should be conducted as a final resort to enable proper soft tissue coverage of the bone. (See "Surgical reconstruction of the upper extremity", section on 'Soft tissue coverage'.)

Antibiotics — The efficacy of the prophylactic antibiotics for open fractures of the long bones has been recognized for decades [41]. However, although there are randomized trials and a meta-analysis demonstrating the effectiveness of prophylactic antibiotics for lower extremity amputations [42,43], the necessity of prophylactic antibiotics for major upper extremity amputations has not been definitively demonstrated.

Nevertheless, for major upper extremity amputations, typically the result of severe injuries that include damage to the soft tissue and neurovascular bundles, antibiotics are usually administered [44,45]. Typically, a first-generation cephalosporin is used [44,45]. Vancomycin is selected for those allergic to beta-lactam antibiotics [46]. If wound contamination is substantial, the addition of an aminoglycoside may be needed [44]. Tetanus prophylaxis may also be warranted.

For minor amputations, the need for prophylactic antibiotics is not clear. In one trial performed on traumatic finger amputations, there was no difference in the infection rate of those treated with antibiotics compared with those who were not [47]. The authors concluded that for fingertip amputations with bone exposure, early wound debridement was the most important measure, and routine prophylactic antibiotics did not contribute to the prevention of postoperative infection.

GENERAL PRINCIPLES — Major amputations are almost always performed under general anesthesia. However, minor amputations are occasionally performed using local anesthetics. (See "Anesthesia for orthopedic trauma", section on 'Anesthesia for upper extremity trauma' and "Upper extremity nerve blocks: Techniques", section on 'Wrist blocks' and "Upper extremity nerve blocks: Techniques", section on 'Digital nerve block (finger)'.)

Stump coverage — For upper extremity amputation closure, a fish-mouth-type incision is typically used, which contrasts with the longer flaps often used in lower extremity amputations.

Stump coverage should be planned early in the procedure. It is essential to cover the bones and muscles with sufficient tissue. When sufficient soft tissue is available, flaps created with residual tissue can be used. Irregular skin or soft tissue flaps remaining after the resection of a malignant tumor or as a result of trauma can also be used to cover the stump. Once completed, excess skin and tissue can be trimmed. When the available tissue is inadequate to create a tension-free closure, skin grafting or a flap procedure may be necessary. (See "Skin autografting" and "Overview of flaps for soft tissue reconstruction".)

Osteotomy versus disarticulation — When amputation that divides the bone (ie, osteotomy) is chosen, the site is determined by the initial condition of the limb. The osteotomy is performed so that the length of the bone is 3 to 5 cm shorter than the planned stump length overall, which allows for coverage of the bone without tension. However, although shortening the bone is the easiest choice to cover the stump, other reconstruction options (skin grafting, flap, free tissue transfer) should be considered to preserve the length of the stump. Prior to closure, the rough surface of the transected bone should be filed smooth using a bone rasp or similar instrument. (See "Surgical reconstruction of the upper extremity", section on 'Soft tissue coverage'.)

Disarticulation is a technique to divide the limb at the joint such that cutting across the bone (ie, osteotomy) is not necessary. Compared with an osteotomy, disarticulation has the advantage of less bleeding since the bone marrow is not exposed. When disarticulation is performed, there is no consensus whether or not to resect the cartilage of the stump. For digit amputations, maintenance of the cartilage has been recommended because it may serve to absorb external pressure [48]. However, in a survey of hand surgeons in the United States, the opinion that the cartilage should be resected (50 percent of respondents) was based on the notion that the residual cartilage is not vascularized and can therefore be a source of postoperative infections [49]. We do not routinely remove the cartilage given the absence of adequate evidence and that doing so adds additional surgical insult to the amputated digit.

Myoplasty — To prevent pain at the stump, muscle tissue is used to create a pad that covers the end of the stump. With myoplasty, the muscles at the end of the stump are sutured together, typically by suturing the extensors and flexors to each other. Suturing muscles to the bone is not commonly used, because unfixed muscles are unstable and cysts can form between the muscle and bone [50].

Prevention of painful neuroma — Neuroma formation is inevitable because of the manner in which axons in the transected nerve sprout from the nerve stump. This is referred to as axonal elongation and is a self-repair mechanism. A neuroma that is located within the stump or scar can become painful, and prevention is aimed at ensuring the nerve is well away from the stump. Thus, to avoid the development of a neuroma, the involved nerves are divided under tension. In doing so, the nerve retracts into the proximal tissue. (See 'Symptomatic neuroma' below.)

Larger nerves are more likely to form symptomatic neuromas. The incidence of neuroma across upper extremity amputations varies widely across study populations, with one systematic review reporting a range of 4 to 58 percent [51]. In one review, the incidence of painful neuroma after transhumeral or transradial amputation was 25 percent [52]. By contrast, in a retrospective review of more than 1000 patients who underwent digit amputations, 6.6 percent developed a symptomatic neuroma [53].

Other methods have been used, such as embedding the nerve stump into nearby muscles and bones or suturing one nerve stump to another one to avoid the exposure of the nerve at the stump [54,55]. The optimal technique for preventing symptomatic neuroma is not known.

In addition to these classic management techniques, two procedures have been introduced for prevention of painful neuroma, each taking advantage of axon sprouting behavior from nerve ends following amputation.

The regenerative peripheral nerve interface (RPNI) is a method of wrapping transected peripheral nerve ends with nonvascularized muscle grafts, providing a target for peripheral nerve ingrowth [56]. New neuromuscular junctions formed in these grafts have been demonstrated on pathology specimens [57]. This technique can be performed on nerves distal to the wrist, which are not indicated for target muscle reinnervation. In a review of 14 RPNI performed on 14 patients with painful neurons of the hand and fingers, 85 percent of patients were pain-free or much improved [58]. RPNI is also performed in major amputations such as transradial and transhumeral amputation [59]. In these cases, the median and ulnar nerves are the main targets for RPNI, but the superficial branches of the radial nerve, the anterior interosseous nerve, and the posterior interosseous nerves should also be targeted to avoid painful neuromas [59].

Target muscle reinnervation may also be effective for preventing symptomatic neuroma. (See 'Target muscle reinnervation' below.)

Target muscle reinnervation — Target muscle reinnervation (TMR) is an effective procedure for attaching a myoelectric prosthesis after an amputation. Target muscle innervation is generally performed during the primary amputation procedure but is occasionally done in a revision surgery. In this procedure, motor nerves that were transected during the amputation are sutured to motor nerves of the residual muscles in the upper extremity or muscles in the trunk, so that the impulse of the ablated nerves reinnervates the muscles in the trunk as new targets. Prostheses equipped with a myoelectric sensor are capable of voluntary control of movement by detecting myoelectric impulses that are generated by the innervated muscles. Matching the motion dominated by the nerve transmitting the signal and the motion of the prosthesis enables the patient to use the prosthesis intuitively [60-64].

In cases of proximal amputations, such as shoulder disarticulations or transhumeral amputations, there may be few or no sites that can catch myoelectric impulses because there are few residual muscles (figure 13A-B). In such cases, muscles in the body trunk such as the pectoralis major, pectoralis minor, serratus anterior, and latissimus dorsi are used for the target muscle (table 1).

TMR is also an effective procedure for the prevention of symptomatic neuromas because it removes the end of the nerve from the limb stump [56,65,66]. The connection of the ablated nerve to the new neuromuscular unit may induce control of the residual stump pain and phantom limb pain via cortical reorganization. A trial that compared the "standard treatment" of neuroma excision and burying the neuroma into the muscle with TMR in patients with chronic postamputation pain reported a substantial improvement of phantom limb pain after one year in patients who underwent TMR [67]. Additionally, this study identified an upward trend toward improvement in residual limb pain after TMR. (See 'Prevention of painful neuroma' above.)

LEVEL-SPECIFIC FEATURES OF THE SURGICAL AMPUTATION

Digit and thumb amputation — For the thumb, dysfunction is inversely proportional to the length of the stump, and thus preservation of length is important. Many functions are maintained when the thumb amputation is distal to the interphalangeal joint; however, a proximal thumb amputation will cause major problems with pinching and gripping.

For digit amputations, the motion of the proximal interphalangeal joint depends on the flexor digitorum superficialis, and the function of the stump is determined by whether part of it can or cannot be preserved. A stump that has little or no motion of the proximal interphalangeal joint will disrupt the function of the adjacent fingers. Thus, if it is not possible to restore the attachment, a ray amputation should be performed (picture 5).

In the case of fingertip amputations, leaving the nail matrix will sometimes cause the development of a painful nail deformity. In addition, the tendons should be pulled out and transected under tension allowing them to be retracted proximally to prevent the quadriga effect (ie, lag in movement of fingers adjacent an injured digit) [68,69].

Transradial amputation and wrist joint disarticulation — Transradial amputation is the most common of the major amputations [3]. With forearm amputations, preservation of length is important for maintaining range of motion and generating torque [70].

For amputations of the distal third of the forearm, much of the forearm motion is retained. For proximal amputations, the length of the ulna should be preserved at least 5 to 7 cm in the amputation, which allows for attachment of the biceps tendon [39]. The tendon is detached from the radial tuberosity and subsequently attached to the proximal ulna with use of suture anchors. By changing the attachment of the tendon, resting tension of the muscle is loosened, which prevents a postoperative elbow flexion contracture.

For wrist disarticulations, the ulnar styloid should remain to stabilize the distal radioulnar joint. Extensor tendons are required to maintain the muscle tension when using a prosthesis [71].

When performing transradial amputation or wrist joint disarticulation, amputation, preferably target muscle reinnervation (TMR) or regenerative peripheral nerve interface should be performed at the same time for postsurgical pain control [72].

Elbow joint disarticulation and transhumeral amputation — Elbow joint disarticulation is performed when the humeral condyle can be preserved, thereby preserving the rotational movement of the shoulder.

For transhumeral amputations, it is desirable to maintain maximum length. If the amputation is conducted more proximally than the pectoral muscle attachment, the movement of the shoulder will be lost.

Shoulder disarticulation and forequarter amputation — The fitting of a prosthesis is quite difficult after a shoulder disarticulation. If the patient plans to use a myoelectric prosthesis, the surgeon should preserve as much muscle as possible and perform TMR. (See 'Target muscle reinnervation' above.)

Forequarter amputations are rarely used in revision amputations and are usually for the treatment of a malignant tumor. The process involves amputation of the arm with an osteotomy in the scapula and clavicle, which leads to loss of shoulder width and axillary contour that is a distinct cosmetic disadvantage. Osteotomy of the clavicle should be performed at the lateral margin of the sternocleidomastoid attachment to preserve the contour of the neck.

POSTOPERATIVE CARE — After skin closure, a well-padded compressive stump dressing is applied to control edema (figure 14) [73].

Postoperative rehabilitation includes prosthesis training and should be initiated during the wound healing process. Early prosthesis fitting promotes maturation of the stump.

After surgery, it is also important to observe the mental state of the patient. If there are concerns, the surgeon should introduce the patient to a specialist as soon as possible. Early detection and treatment of psychological pathology is an important component of postoperative care.

COMPLICATIONS FOLLOWING SURGICAL AMPUTATION — Complications occurring after upper extremity amputation include those in common with other surgeries (deep vein thrombosis, hematoma, surgical site infection, and wound complications) and those that are specific to amputation, which are reviewed briefly below. A serious and frequent postamputation complication is neuropathic pain caused by nerve transection. It includes symptomatic neuroma and phantom limb pain. In a review of 148 major upper extremity amputations, neuropathic pain occurred in 42 percent [74]. The study also reported increased risk in patients with traumatic amputation, transhumeral amputation, and forequarter amputation.

Symptomatic neuroma — Neuroma formation after an upper limb amputation is a serious cause of stump pain. Stump pain from symptomatic neuroma can lead to the failure or abandonment of a prosthesis. Moreover, the treatment of a symptomatic neuroma is challenging. Traditionally, a symptomatic neuroma is treated by capping the nerve stump with a silicone cap, or by burying the stump into bone or muscle [75]. One author reported pain reduction in all upper extremity amputees by burying the nerve stump into adjacent tissues after a resection of a neuroma [52].

However, most reports are based on small study samples, and an optimal method for treating symptomatic neuromas has not been established, emphasizing the importance of prevention. (See 'Prevention of painful neuroma' above.)

Phantom limb pain — Phantom limb pain is a common problem following both lower and upper extremity amputation, and it needs to be distinguished from other causes of stump pain. Phantom limb pain is reported in 30 to 80 percent of cases of upper extremity amputations [74,76,77].

Phantom sensations are when the patient perceives sensation in a severed body part, and when that perception is pain, it is referred to as phantom limb pain. Changes occur in both the central nervous system and peripheral nerve system after an amputation that depend on the subsequent reorganization of the primary somatosensory and motor cortices of the brain [78].

Risk factors for phantom pain include extremity pain prior to the amputation in patients with ischemic disease, male sex [79], and bilateral amputations [80-82]. Transradial amputations carry more risk than other amputations for phantom limb pain [83]. Psychological factors such as stress and depression also influence the development of chronic phantom limb pain [84].

Various pain management strategies treatments have been used, including pharmacologic agents (eg, opioids, ketamine) and regional anesthesia (eg, epidural for acute phantom pain), but there is no consensus on the best treatment [81,85,86]. Most of these approaches are used because of their success with other types of neuropathic pain. However, strong evidence supporting this method of treatment for phantom limb pain has yet to be established.

Several nonpharmacological treatments exist as an alternative approach for treatment of phantom limb pain. After amputation, the lack of afferent sensory signals corresponding to the transmission of the efferent motor commands to the limb causes visual-proprioceptive dissociation in the brain [87]. The use of nonpharmacological treatments can assist in the correction of this dissociation. As an example, mirror therapy is commonly used to reduce phantom limb pain [87]. A randomized trial to evaluate the effectiveness of mirror therapy in upper extremity amputees reported a 38 percent decrease in pain scores [88]. To resolve visual-proprioceptive dissociation, brain-computer interface (BCI) training may also be a potential treatment. In a small review of 12 patients with chronic upper extremity phantom limb pain, participants trained with a BCI to control an image of a phantom hand [89]. The investigators found that a three-day training period significantly reduced pain for one week. (See "Evaluation of chronic non-cancer pain in adults" and "Approach to the management of chronic non-cancer pain in adults".)

OPTIMIZING FUNCTION FOLLOWING AMPUTATION — Following upper extremity amputation, options to optimize functionality include the use of a prosthesis or undergoing a hand transplant. Patients may choose not to use a prosthesis. Those undergoing stump revision for congenital deficiencies can sometimes function well without using prostheses, preferring the normal tactile sensation of the stump [90-92].

Types of prosthesis for upper extremities — The main types of upper extremity prostheses include passive (cosmetic), body powered, and externally powered [93].

The wearing of the prosthesis to the amputated limb is mainly achieved through the self-suspended sockets, suction sockets, harness-suspended sockets, and "osteointegration" [50]. Osteointegration involves embedding the prosthesis into bone and is not routinely conducted. But, osteointegration enables patients with a short stump to wear a prosthesis without a harness suspension and improves the range of motion in the residual joint [94].

Passive — Passive prostheses focus on improving appearance and do not improve active motor control. Passive prostheses can be static or adjustable. The former cannot move and is limited to basic tasks, such as fastening and stabilizing objects. As an example, the patient can use the prosthesis to stabilize the trunk by balancing the spinal column. The adjustable prosthesis includes some sort of movable mechanism that can be used by adjusting the prosthesis posture with the normal hand, enabling the patient to grasp objects [95]. In many cases, passive prostheses have relatively good appearances and do not impede patients in their daily activities.

Body powered — Body-powered prostheses allow patients to retain a level of motion after an amputation. They have a hook designed to open and close in response to movement of the limb stump (picture 2).

Externally powered — Externally powered prostheses provide motion based on electromyogram (EMG) signals that can be detected from the residual muscles. By combining the signals from an EMG, the patient can achieve motion, including flexion/extension and rotation. The number of actions achievable is determined by the number of muscles. By combining motions (for example, elbow flexion and forearm pronation), multiple actions are possible with a single muscle contraction signal [96]. Drawbacks of externally powered prostheses are their cost and weight. As technology improves, so has the appearance of these devices.

Operation of an externally powered prosthesis is intuitive when the function of the residual muscle from which the electromyogram signals are detected is similar to the motion reproduced by the prosthesis. However, there is not necessarily an intuitive relationship (such as a signal captured from the pectoralis muscle to stimulate moving the finger of the prosthesis).

Target muscle reinnervation (TMR) enables the intuitive use of a myoelectric prosthesis (figure 13A-B). TMR has also been reported to increase the number of EMG signals detectable by the prosthesis, further enhancing control. Moreover, the tactile sensation is indispensable for the motion of the prosthesis. It has also been suggested that tactile sensation activates the somatosensory feedback mechanism, which has the possibility to improve phantom limb pain [97]. (See 'Target muscle reinnervation' above.)

Hand transplantation — Hand transplantation is an alternative to a prosthesis for an upper extremity deficit. A transplanted hand seems to be ideal because of its natural weight, look, intuitive control, and natural sensory feedback. In cases of a bilateral loss of the upper extremities, especially below the elbow, hand transplantation may have better results compared with using a prosthesis [98]. However, hand transplantation is expensive and requires lifelong immunosuppressive therapy [99]. Physical therapy to achieve optimal outcomes is time consuming, and psychological problems sometimes arise and can lead to the need for reamputation [100]. For these reasons, prostheses are considered to be the preferred treatment for most upper extremity amputation patients. Hand transplants should be limited to only those patients requiring bilateral below-elbow amputations [101]. In terms of cost utility, the cost of bilateral hand transplant exceeds the socially acceptable threshold [102].

OUTCOMES

Functional — The goal of amputation is to treat the medical condition necessitating the amputation while making a stump that is painless and functional (with or without a prosthesis) [73]. Lower extremities are required to support loads from the trunk, whereas the functions required from the upper extremities are diverse.

There is no standardized, specialized test to evaluate function or quality of life after an upper extremity amputation, and therefore objective assessment of function is difficult [39,73,103,104]. Various factors, such as use or abandonment of prosthesis and return to work, have been used as indicators. Because prosthesis abandonment is caused by discomfort or lack of functional gain, regular use of a prosthesis is often applied as a marker of success following upper extremity amputations. But, because of heterogeneous samples and methodological differences between studies, the reported rates of use or rejection vary widely. In one review of 200 articles published over 25 years about the usage of prostheses, the mean rejection rates by adults of body-powered and electric prostheses were 26 and 23 percent, respectively [103].

After an upper extremity amputation, many patients return to work, but the probability of doing so appears to be determined by the level of amputation [105]. Patients with amputation above the elbow often cannot return to work, or, in many cases, it is necessary to alter their work responsibilities [106]. By contrast, among patients who have had forearm amputation, the rate of return to work is about 50 percent, which is lower compared with patients who have undergone replantation, for whom about 75 percent return to work [30,107].

Psychological — Many studies have investigated the psychological and social consequences of an upper extremity amputation. Amputation affects a patient's mental state, work ability, and body aesthetics. The memory of the trauma that led to amputation can lead to post-traumatic stress disorder (PTSD) [108-110]. In a retrospective study from a single institution, 20 of 39 upper extremity amputees screened positively for depressive tendencies using the Center for Epidemiologic Studies Depression Scale and 27 screened positive for PTSD [110]. Early identification and treatment can prevent the progression of psychological pathology and alleviate its adverse effects on the patient's health [111]. (See "Posttraumatic stress disorder in adults: Epidemiology, pathophysiology, clinical features, assessment, and diagnosis".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Severe blunt or penetrating extremity trauma" and "Society guideline links: Soft tissue sarcoma".)

SUMMARY AND RECOMMENDATIONS

●Upper extremity amputation – Amputation of an upper extremity leads to loss of function, affecting the patient physically and mentally. Major amputation is defined as amputation proximal to the wrist joint; minor amputations involve the hand and digits. Most upper extremity amputations are minor amputations. (See 'Introduction' above and 'Types of upper extremity amputations' above.)

●Causes of upper extremity amputation – The leading cause of upper extremity amputations is trauma, but ischemic disease, malignant tumors, congenital deformities, or infection can also lead to amputation. The rate of ischemic disease leading to amputation in the upper extremities is much lower compared with the lower extremities. (See 'Indications' above.)

●Upper extremity evaluation – When treating a patient with traumatic amputation, the patient's general condition should be evaluated and reasonable decisions regarding the extremity made simultaneously. These decisions include whether to attempt replantation, try other reconstruction measures, or perform revision amputation. Sometimes immediate revision amputation is needed to stabilize the patient's general condition. (See 'Upper extremity trauma management' above and 'Replantation versus completion amputation' above.)

●Postoperative care and complications – Postoperative care following surgical amputation includes wound care, early prosthesis fitting, and postoperative rehabilitation. Complications include those associated with surgery in general (eg, deep vein thrombosis, hematoma, wound problems) and those specific to the amputation, such as stump pain (sometimes due to neuroma formation) and phantom limb pain. (See 'Postoperative care' above and 'Complications following surgical amputation' above.)

●Functional outcomes – The outcomes of upper extremity amputations are difficult to estimate, and various factors such as use or abandonment of prosthesis and return to work are used as an objective indicator. Options to optimize function following upper extremity amputation include the use of a prosthesis or undergoing a hand transplant. Indications for hand transplantation are limited due to cost and need for chronic immunosuppression. Prostheses can be passive (cosmetic), body powered, or externally powered. To drive a body-powered prosthesis intuitively, the technique of target muscle reinnervation (TMR) is used. (See 'Outcomes' above and 'Optimizing function following amputation' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Jennifer M Sterbenz, BS, who contributed to an earlier version of this topic review.