Amputation of an upper limb is a catastrophic event that frequently results from high-energy trauma in a young, otherwise healthy patient cohort.^1,2,3 Of the 1.6 million individuals in the United States living with limb loss in 2005, 34% (541,000) had upper limb loss; 92% of hospital discharges attributable to upper limb loss resulted from traumatic mechanisms of injury, 41,000 of which were proximal to the finger.^4,5 More than 2,200 major limb amputations have been performed as a result of injuries that occurred in US military conflicts over the past decade, including Operation Iraqi Freedom and Operation Enduring Freedom, and nearly 18% were upper limb amputations. Of the major upper limb amputations performed in military personnel to date for these conflicts, 50% were transradial and 10% were wrist disarticulations (John C. Shero, MHA, FACHE, Director, Extremity Trauma and Amputation Center of Excellence, unpublished data, September 2021). Amputations below the level of the elbow are the most frequently performed amputations in the upper limb; the transradial amputation is the most common level in both civilian and warrelated traumatic injuries.⁶

The surgical principles of upper and lower limb amputations are quite similar, but key differences in morphology and function require special attention when considering upper limb amputation. The primary goal in lower limb amputation is to provide a well-padded, durable residual limb that facilitates weight bearing, maximizes ambulatory function, and minimizes energy consumption required for ambulation; the goals in upper limb amputation are to maximize precise function and provide a good cosmetic result. To ensure appropriate preoperative planning and optimal patient outcomes, the surgeon should be aware of prosthetic capabilities, prosthesis acceptance rates, and the functional outcomes associated with transradial amputations and wrist disarticulations.⁷

An integrated team approach is vital to maximize amputee care. In addition to orthopaedic surgeons, specialists in trauma surgery, physical medicine, anesthesiology, pain management, rehabilitation, occupational therapy, physical therapy, mental health care, social work, nursing, and prosthetics should be involved in the care of patients with an upper limb amputation. Patient- and family-centered participation in the decision-making process enhances a patient’s acceptance of the amputation and satisfaction with its outcome.^8,9 A multidisciplinary care approach is especially essential for patients with multiple limb amputations, which frequently occur after high-energy combat injuries. The patient often has numerous comorbid conditions and requires complex and comprehensive treatment.¹⁰ Good functional outcomes and prosthetic acceptance rates can be expected with a well-coordinated rehabilitation protocol and timely prosthetic fitting.¹¹

A good understanding of anatomy, adherence to sound orthopaedic surgical principles, and a systematic approach to the evaluation and treatment of the amputee are essential to achieve the best results.¹² In general,
guillotine amputations should be avoided unless they are clinically indicated, which is uncommon. In traumatic amputations, all devitalized tissue should be meticulously débrided, taking special care to identify and protect all important neurovascular structures to maximize the final functional result.^13,14 Negative-pressure dressings are effective for staged surgical treatment because they limit the frequency of bedside dressing changes, improve pain control, and provide surgeons with greater flexibility when considering soft-tissue reconstruction options for more complex cases.^15,16 The timing of final amputation coverage or closure depends largely on surgeon experience, but a wound bed devoid of necrotic tissue and infection and a tension-free closure are critical to success.¹⁷

In general, preserving maximal limb length is preferred in upper limb amputations, but this goal must be balanced with consideration for wound-healing capacity and residual limb coverage, patient preference, rehabilitation potential, and local prosthetic expertise and availability. With increasing limb length and preservation of joints, enhanced positioning of the terminal residual limb and/or prosthetic device in space is achieved, allowing for the best functional results and improved outcomes. When considering amputation below the level of the elbow, the scope of the injury often determines the amputation level. The requirements and capabilities of prostheses for each amputation level must be understood and considered. Consultation with a prosthetist is recommended early in the decision-making process.

Concomitant fractures should be considered for surgical stabilization when functional limb length or joint preservation can be achieved, although higher complication rates can be expected. However, preservation of the established limb length at the time of fracture fixation is generally achieved.¹⁸ Additional soft-tissue coverage options, including skin grafts and flaps, should be strongly considered when residual tissue flaps provide inadequate coverage for a distal amputation below the elbow and shortening the residual limb will diminish prosthetic fitting options and functional outcomes. This is perhaps most important in attempts to preserve the elbow joint but also when optimizing residual limb length for a transradial amputation. Using microvascular free tissue transfer in appropriately selected patients to maximize limb length and provide durable soft-tissue coverage has proved successful in upper limb amputations.^19,20,21 In the upper limb, indications for free tissue transfer include shoulder joint preservation by selecting a transhumeral amputation level, elbow joint preservation, and preservation of bone more than 7 cm below the shoulder or elbow. Relative indications include wrist joint preservation and skeletal preservation between 5 and 7 cm below the shoulder or elbow.^7,22 Although upper limb amputations that require skin grafts or flaps take longer to heal, the functional benefits of joint and/or limb-length preservation usually outweigh delays in rehabilitation and prosthetic fitting.

Careful attention to nerves and muscles is critically important in upper limb amputation because symptomatic neuromas are common.²³ Before final closure of an upper limb amputation, all involved sensory and motor nerves should be identified. All motor branches to muscle flaps within the surgical field also should be preserved to prevent muscle denervation that results in loss of muscle mass for limb padding and possible loss of sites for myoelectric signals. Nerves should undergo gentle traction neurectomy to locate neuromas away from the distal amputation myodesis or skin closure. Although more aggressive traction neurectomy was previously recommended for large peripheral nerves with motor function, preservation of additional nerve length while preventing more distal exposure of neuromas can ensure the possibility of future reconstructive surgery.

Stabilizing the musculotendinous units of the residual limb under physiologic tension at the time of amputation closure serves two main purposes. First, it facilitates robust coverage over the distal bone end, providing comfortable padding for the prosthetic socket while preventing painful bursa formation from mobile muscle units. Second, optimal contractility characteristics of the muscle are preserved, improving muscle signal quality and maximizing myoelectric control of a prosthesis, while also maximizing terminal residual limb control for a body-powered prosthesis. Myodesis, the process of attaching musculotendinous units directly to bone, is the surgical technique that provides the most stable construct over the distal bone end. Myodesis is typically performed by suturing the muscle and/or tendon to the bone end, usually through drill tunnels with braided nonabsorbable suture, or less commonly, to periosteum. Myoplasty, which attaches agonist muscles to antagonist muscles over the bone end to create physiologic tension, and myofascial closure, which sutures muscle and fascia together, are less stable constructs. These procedures may be indicated when myodesis cannot be achieved, for secondary muscles after primary myodesis, or to contour the remaining muscle bellies before closure. Although no data support the superiority of myodesis over myoplasty, myodesis is recommended in upper limb amputations to provide the most stable limb and best isolate muscle signals and myoelectric prosthetic control.

The advantages of wrist disarticulation include preservation of forearm rotation when the distal radioulnar joint (DRUJ) is preserved, elimination of painful radioulnar convergence compared with transradial amputation, improved weight bearing directly through the terminal residual limb, enhanced functional length, and better prosthetic suspension. Historically, the main disadvantage of wrist disarticulation has been limited available prosthetic options because of the short working length and limited space available for the terminal device.²⁴ In 1972, before the introduction of modern wrist prostheses, a survey of US surgeons indicated a preference for distal transradial amputation over wrist disarticulation.²⁵ Even with recent advances in prosthetic design and materials, which
have greatly improved function for an individual treated with wrist disarticulation, a preference remains in many amputation centers for revision to transradial amputation because of patient dissatisfaction with outcomes after wrist disarticulation.⁷ Consultation with an upper limb prosthetist is highly recommended when a decision must be made between preservation of a wrist disarticulation or revision to a transradial amputation.

A successful wrist disarticulation requires a healthy, intact DRUJ.¹ Preservation of the triangular fibrocartilage complex and radioulnar ligaments facilitates stable pronation and supination, with an expected total arc of approximately 100° to 120°.^5,26,27 The thick palmar skin of the hand should be used for distal coverage, but often, skin flaps for final wound closure will be dictated by the injury.¹ The radial styloid should be saved for prosthetic suspension; it can be contoured to prevent prominence and skin irritation or breakdown at the prosthetic interface. The ulnar styloid is often excised to prevent soft-tissue prominence distally. It is crucial to perform myodesis of the flexor and extensor tendons to maintain tension in those muscles to provide necessary myoelectric prosthetic function. Important nerves to identify include not only the median and ulnar nerves, but also the superficial radial nerve, the palmar cutaneous branch of the median nerve, the dorsal ulnar cutaneous nerve, and possibly the terminal medial and lateral antebrachial cutaneous nerves. These nerves should be divided proximal to the level of amputation closure using gentle traction neurectomy and buried under muscle to prevent the development of painful neuromas. One exception is preservation of cutaneous nerves to a skin flap required for distal amputation coverage.⁷ Additional nerve techniques, such as cauterization, suture ligation, and anesthetic injection, have been described but are not performed by the author of this chapter because of a lack of proven efficacy and theoretical concerns about exacerbating neuropathic pain.

Surgery for wrist disarticulation is typically performed with the patient supine and under regional anesthesia. An indwelling peripheral nerve catheter placed intraoperatively can help control postoperative pain and aid in initial recovery. Initial dissection and amputation is performed using a tourniquet to allow accurate identification of all structures in a bloodless field. Under traumatic conditions, all available viable skin flaps are preserved and considered for final closure. If amputation is performed under elective conditions, skin flaps can be designed to allow the use of durable palmar skin over the distal residual limb. The radial and ulnar arteries are dissected free and double ligated. Large veins are typically ligated; small veins can be cauterized. Peripheral nerves are identified and dissected, including the median nerve, ulnar nerve, all branches of the dorsal sensory radial and ulnar nerves, and any terminal branches of the lateral and medial antebrachial cutaneous nerves. All cutaneous nerves to skin flaps intended for final closure should be preserved. Gentle traction neurectomy of all nerves is preferred to place them just proximal to the myodesis and the distal residual limb surface. This technique should minimize the likelihood of development of painful neuromas and preserve maximum nerve length for future limb reconstruction procedures. All crossing tendons are divided, followed by sharp amputation at the level of the radial and ulnar carpal joints, with great care taken to preserve the triangular fibrocartilage complex and the dorsal and palmar radioulnar ligaments to maintain DRUJ function. The radial styloid prominence should be assessed for minor bone contouring. The ulnar styloid is typically excised if prominent, but care should be taken to preserve the foveal attachment of the triangular fibrocartilage complex. The tourniquet is released, and strict hemostasis should be obtained before final amputation closure.

All hand and wrist flexor and extensor tendons are attached to the distal radius using braided, nonabsorbable suture through drilled tunnels, as is done in the myodesis technique. Myoplasty can then be performed for additional muscles to contour the residual limb, provide additional padding, and ensure maximum muscle working length (Figure 1). Skin flaps are closed in a tension-free manner in layers, with resorbable and nonresorbable monofilament sutures. Drains and/or incisional vacuum-assisted closure dressings can be placed according to surgeon preference and the clinical situation. The author of this chapter commonly uses incisional negative-pressure wound therapy for complex closure in combat-related amputations. Although the efficacy of incisional negative-pressure wound therapy has not yet been illustrated, it is thought to enhance wound healing and reduce postoperative wound dehiscence, seroma, and hematoma in higher risk patients.^28,29,30 Although dermal substitutes, skin grafts, and pedicle and free tissue flaps can be considered in cases in which primary skin closure cannot be obtained, in the practice of the author of this chapter, this typically indicates consideration of a more proximal transradial amputation level with similar functional outcomes.

Bulky gauze dressings are applied, followed by a compression dressing to minimize edema. Splints are typically not used, and certainly not above the elbow unless clinically indicated to prevent joint contracture. Postoperative elevation is recommended to reduce swelling and optimize the limb for prosthetic rehabilitation. The use of specialized elevation foam pillows helps improve patient compliance and minimizes pain.

Transradial amputation is the most common major upper limb amputation and has the highest prosthetic acceptance rates of amputations performed in the upper limb.⁶ Preserved shoulder and elbow joints, a long lever arm, and forearm rotation allow the individual with a distal transradial amputation to easily position the terminal prosthesis in space. Transradial amputation
is cosmetically appealing because of the ability to fit body-powered or myoelectric prostheses with quick-disconnecting components, while maintaining equal limb lengths.