Until recently, patients with digit, partial hand, or transcarpal amputations were often offered passive (nonfunctioning) cosmetic prostheses (restorations).11 Depending on the characteristics of the residual limb, a functional prehensile post might have been fabricated to regain some grasp and release capability of the affected limb. Recent advances in technology and microprocessors have made externally powered options more readily available (Figure 30-3).¹² These advances permit electric control despite the extremely distal amputation site. Consideration must be given preoperatively to any remaining functional digits. The status of sensation and mobility of these digits should not be understated. If functional range and sensation are inadequate, the surgeon considers a more proximal level of amputation.

The wrist disarticulation residual limb provides a long and functional lever for prosthetic use.13 If the radial and ulnar styloid processes are preserved, then the prosthetist can use a positive suspension strategy over these prominences to keep the prosthesis and stable suspended on the residual limb, making harnesses unnecessary. The disadvantage of wrist disarticulation, however, is limitation in room to fit a wrist and hand unit into a cosmetically acceptable prosthesis. If the styloid processes have been modified or removed during surgery, more aggressive proximal suspension strategies are necessary. In addition, the extra residual limb length leads to a difference in arm length once the wrist and prosthetic hand unit is in place, which might be cosmetically unacceptable to the patient. In such cases, a more proximal amputation would allow for a full complement of prosthetic options.

For most adult transradial prostheses, nearly 8 inches of space is necessary beyond the distal residual limb for the prosthetic wrist rotator and TD or hand.13 Similarly, at the transhumeral level, approximately 6 inches of space must be present beyond the distal residual limb to accommodate a mechanical elbow mechanism within the prosthesis.¹⁴ For patients with a short residual humerus, a conventional (body-powered) prosthetic system may not be realistic, and even an externally powered prosthesis may be difficult or problematic to fit, suspend, and control. When the residual humerus is short, it may be necessary to treat a transhumeral amputation functionally as a shoulder disarticulation (Figure 30-4).

Positive models to fabricate any contemporary prosthesis can be secured with conventional plaster direct molding techniques similar to those used for lower-extremity amputations. Model acquisition and data collection are also possible using computer-aided design. Both direct contact and optical methods are finding ever-increasing utility in modern practice. This technology is particularly valuable as a means to quantify and document volume and shape changes, enhancing fit and function for optimal clinical outcomes (Figure 30-5).

Edema and volume control are additional key elements of preprosthetic care. If the wound site is adequately protected and bandaged, compressive wraps or shrinkers should be used as soon as possible. In most cases, multidirectional shrinker garments are more effective than other methods, including elastic bandages.27 Shrinkers appear to more efficiently control volume and shape the residual limb. When donned properly, shrinkers have far less tendency to migrate or shift position on the residual limb. In addition, shrinkers are more effective at creating the consistent distal toward proximal pressure gradient that is most effective. The compressive garment should terminate proximal to the joint above the amputation site when possible. With the transhumeral amputation, this requires the shrinker to include a modified shoulder cap. Such a device is rarely commercially available and usually requires custom fabrication on site. This additional effort has been shown to produce favorable results in comparison with shrinkers that terminate more distally.²⁶ Due diligence must be exercised to ensure that appropriate tension and compression gradients are achieved and maintained. Effective and timely volume management influences more than the residual limb volume and shape; many patients report that this compression is a surprisingly efficient tool in the management of phantom sensation.²⁷

Skin care can present some significant challenges, particularly when an individual has sustained a traumatic amputation. Chemical and electrical injuries with associated skin grafts can become problematic, particularly when irregular and uneven surface topography is present.28 Maintaining skin integrity throughout both the fitting and postdelivery phase of rehabilitation is extremely important. The appropriate medical professional should carefully assess any postoperative open lesions. Blast and percussion injuries also present a complex array of socket interface and electrical conductivity issues.²⁹ This type of injury frequently displays an unusual soft tissue consistency. The tissue is unlike that of crushing, degloving injuries. Tissues exposed to the enormous energy associated with blast injuries frequently respond to the outside compressive forces of shrinkers and preparatory sockets much more dramatically than do tissues injured by other sources. This phenomenon must be considered carefully, as its effects profoundly affect any rehabilitation plan.

The nature of any volume management protocol in and of itself begins the limb maturation and desensitization process simultaneously. Further and more focused efforts must be undertaken to assure that limb volume is both stabilizing and fostering a limb shape or contour that is favorable to donning, wearing, and operating a prosthetic device.²⁸ Limbs with large longitudinal contours or bulbous distal contours are least desirable. Residuum with insignificant tissue or skin coverage should also be avoided whenever possible. Ideally the residual limb is long enough to provide a functional lever arm but not so long as to preclude the use of a wide array of prosthetic components. Residual limbs with effective myodesis frequently display smaller myoelectric artifact without any apparent or material loss of volitional potential.

Preprosthetic ROM should be maximized regardless of the planned prosthetic intervention. Strengthening of the muscles about and proximal to the amputation is paramount. However, a more global approach to strengthening affords the patient a more expeditious and complete rehabilitation. These efforts to maximize ROM and increase volitional power should not overlook the secondary movers or accessory stabilizers. For patients with transradial amputations, for example, maximizing ROM and strength of pronation and supination is an important determinant of positive functional outcomes.

Patients and families facing amputation, whether congenital or acquired, adjust and cope with absence or loss of the limb differently.30 The extent or level of involvement often has little to do with the complexity of the adaptation process. All persons must find ways to deal with the functional and aesthetic issues related to limb loss. Adaptation is an ongoing process rather than a specific event. In many cases the services of a qualified psychotherapist are valuable, providing the patient and caregivers are amenable to such intervention.

Most professionals agree that there is a fairly short window of opportunity within which the prospects for successful rehabilitation are greatest, although there is disagreement about the duration of this “optimal rehabilitation” period. In most circumstances the earlier a patient can be evaluated, fitted, and trained, the more likely a positive rehabilitation outcome occurs.⁶ Malone and colleagues²⁵ suggest high levels of success with patients fit within the first 30 days following amputation. In addition, individuals fit with a prosthesis as early as possible return to work quickly, many within 4 nbsps of injury.^6,25

A significant percentage of patients with upper-extremity amputations elect not to use a prosthesis on a regular basis.6 In many cases this decision can be traced to a poorly conceived or executed prosthetic device that was provided early in the patient rehabilitation process.²⁵ Some potential wearers report that the devices they have been exposed to are uncomfortable, heavy, and too slow during use or difficult to don and suspend.⁶ The advent of advanced materials has enabled prosthetists to build lighter, stronger, and more comfortable systems, as well as extremely cosmetic restorations. Despite these advancements, not all individuals with amputations integrate a prosthesis into their body image. The prosthetist or rehabilitation team should follow patients who choose not to use a prosthesis initially at regular intervals (often yearly) to ensure that their functional needs are being met. Given the rate of technological development, new components or devices are likely to become available to address problems the patient might have had at an earlier time.

This category of prosthesis consists of systems that do not possess the ability to actively position a mechanical elbow in space or actively provide grasp and release function, or both. The absence of these properties does not, however, render the prosthesis as passive as the name would suggest. These devices are extremely functional in terms of supporting objects or stabilizing items during bimanual tasks and activities, especially for young children with congenital deficiencies.32,³³ These systems most frequently have a self-suspending design and use a realistic hand as a TD. Suspension is achieved either with specific socket interface geometry or suction negative pressure. The absence of operational mechanical components generally results in an extremely lightweight prosthesis.

The finish of these devices varies widely. Production latex cosmetic gloves provide an cost-effective medium for many patients. Many individuals, however, seek out more realistic restorations (Figure 30-6). These restorations require substantially greater investments in time and financial resources. This investment is most often rewarded with an extremely aesthetic, very natural appearing device. Silicone is the media of choice for these cosmetic limbs, primarily because it is practically impervious to outside contaminants. Where latex readily stains and deteriorates in ultraviolet light, silicone does not mark and, for all practical purposes, is inert. Generally, the additional cost of silicone is mitigated by its superior cosmesis, durability, and increased coefficient of friction (Figure 30-6).

Laser scanning and computer modeling to create near perfect “mirror“ images of high level amputations, such as shoulder disarticulations, and scapulothoracic amputations (see Figure 30-6, A).

Conventional (body-powered) systems include any prosthesis that uses a control cable system to translate volitional muscle force and shoulder or arm movement to operate a TD or prosthetic elbow.34 The patient must use specific strategies in order to effectively create enough excursion in the cable to control the TD or preposition the forearm in space. In most instances the glenohumeral joint contributes the largest amount of excursion in conventional prosthetic control. Glenohumeral flexion typically has more than ample excursion and satisfactory power to provide useful motors for this type of control. Additional excursion can be achieved through scapular and biscapular abduction (scapular protraction). These secondary movements allow a well-trained and skilled prosthetic wearer to increase the functional work envelope, the space in which the wearer can effectively control the TD.

For most conventional upper-extremity prostheses, the functional envelope is limited to a relatively small area below the shoulders, above the waist, and not far outward past shoulder width.³⁴ Many prosthetic wearers have significant difficulty with tasks that involve grasp-and-release tasks above the head or down near the feet. Because the control strategy involves generating cable excursion through flexion or protraction, or both, tasks and activities occurring behind the back are impossible. Despite these functional limitations, conventional prostheses have provided many patients with reliable and durable prosthetic systems.

Figure-of-Eight Suspension and Control Cable

The foundation of all conventional body-powered prostheses is a harnessing system that provides both a firm anchor for the control cables and, in many cases, a stable means of suspension. Most conventional systems use a figure-of-eight–style harness (Figure 30-7). The terminal ends of the figure-of-eight are formed by means of an axillary loop that is fit over the opposite shoulder, a control attachment cable, and an anterior suspension component on the amputated side. Most prosthetists recommend that the center of the figure-of-eight be positioned just below the seventh cervical vertebra and slightly toward the sound side.³⁴ The straps of the two axillary loops can be mobile by means of attachment to a circular ring or fixed with a sewn cross point. The use of a center ring often makes the donning process less difficult and appears to provide the most satisfactory ROM. Harnessing materials are most frequently constructed of medium weight Dacron webbing with both leather and plastic integrated components.

Control and Suspension for Bilateral Prostheses

For patients with amputation of both upper extremities, careful clinical consideration must be given to achieving an easily donable and highly functional prosthetic system. Instead of using a traditional figure-of-eight harness with a contralateral axillary loop for each prosthesis, the two anterior suspension components are linked.35 In this arrangement, the bilateral prosthetic system is effectively stabilized by the equal counteracting forces from each prosthesis. On the basis of the patient’s functional needs, the prosthetist may use either a single- or dual-ring system to maximize the efficiency of the conventional prostheses (Figure 30-8). The second ring in the system, mounted below the primary ring, is used exclusively for the control attachment straps. The more proximal ring is used for the anterior suspensor straps and, for patients with bilateral transhumeral residual limbs, the connection of elbow locking straps.

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