ACQUIRED AMPUTATIONS

TERMINOLOGY

The terminology utilized for acquired amputations follows the convention for adult limb loss. Upper extremity amputations include intrascapulothoracic, shoulder disarticulation, transhumerai (above-elbow amputation), elbow disarticulation, transradial (below-elbow amputation), wrist disarticulation, and partial hand amputations. The types of lower extremity amputations are translumbar (hemicorpectomy), transpelvic (hemipel-vectomy), hip disarticulation, transfemoral (above-knee amputation), knee disarticulation (through-knee), trans-tibial (below-knee amputation), ankle disarticulations (ie, Syme, Boyd, and Pirigoff), and partial foot (ie, Chopart and Lisfranc) (35). Figure 13.3 illustrates present classifications of acquired amputations.

TRAUMATIC INJURIES

In the pediatric age group, the most common causes of acquired amputations are trauma and disease (36). Trauma causes limb loss twice as often as disease (37). The most common traumatic injuries result from automobile and motorcycle collisions and train accidents. Causes for traumatic injuries vary with region. In rural areas, farm accidents, lawn mower accidents, and high-tension wire injuries occur more frequently (38—41). For the older child, vehicular accidents, burns, gunshot wounds, and power tools are the most frequent causes of limb loss. Boating accidents can produce amputations by propeller injury. Sadly, in the 1- to 4-year-old age range, power tools such as lawn mowers and household accidents are frequent mechanisms of amputation (42,43). Fortunately, in those traumatic events where digit or even hand replantation is possible, pediatric patients experienced improved functional and cosmetic outcomes with less frequent complications than their adult counterparts. However, patients identified as African American or Hispanic and those without insurance were less frequently noted in another study to have attempted replantation (44,45). For those injuries that require inpatient hospitalization, a

FIGURE 13.3 Classifications of acquired amputations.

multidisciplinary approach produces the best outcome at the time of discharge. Older adolescents and patients with traumatic leg amputations have longer stay during initial hospitalization and higher hospitalization rates (46).

A single limb is involved in more than 90% of acquired amputations, of which 60% involves the leg (see Table 13.2). The male-to-female ratio of acquired amputation is 3:1.

TABLE 13.2 LONGITUDINAL LIMB DEFICIENCIES

TUMORS

Tumors are the most frequent cause of amputations due to disease. Tumors represent the most common cause of amputations in the European Surveillance of Congenital Anomalies (EUROCAT) data system (1). The highest incidence of malignancy is in the 12- to 21-year-old age group. Osteogenic sarcoma, Ewing's sarcoma, and the rare rhabdomyosarcoma are responsible for the majority of tumors resulting in amputation (47,48). Unprecedented improvement in survival has occurred with earlier detection and combined therapy (49). Definitive surgery for osteosarcoma depends upon the site of the primary tumor and the extent of invasion or metastasis (50). Surgical removal of the affected bone and the surrounding soft tissue remains the treatment of choice, whether by amputation or limb-salvage procedure. Limb salvage with an endoprosthesis can be offered to 90% of children with osteosarcoma (49-51). This procedure, which involves replacing the affected bone with a metal endoprosthesis, is accompanied by orders to prohibit contact sports. With the advent of extendable endoprostheses, it has been suggested that children who have undergone this treatment have results that are superior to those who have undergone amputation surgery (52-54). Families may wish to pursue this due to the improved cosmesis, to prevent the loss of a limb in a growing child, and ultimately, to achieve the best functional outcome.

The surgical procedure of choice is that which obtains a tumor-free margin of 5 to 8 cm above the proximal limit of the medullary tumor. The decision to proceed with limb salvage or amputation is dependent on the aggressiveness of the tumor, the stage, the responsiveness to neoadjuvant therapy, and the likelihood of obtaining tumor-free margins (55-57). The knee poses a challenge for soft tissue sarcomas. Despite complications, the knee may be reconstructed with allografts (58,59). Rehabilitation physicians discuss the likely functional outcomes of each choice and provide continued support and maintenance of functional status during the chosen course of treatment. During the limb salvage, amputation, and recovery process, rehabilitation physicians and therapists promote strategies to prevent any decline in function, treat pain, and anticipate progression of potential treatments.

Chemotherapy has now proven to be an effective adjunct to surgery. Prior to 1972, only 15% of the children were disease-free and survived with surgery, compared to the 60% to 70% who now survive with surgery and the addition of chemotherapy (60,61). Rehabilitation may be confounded by factors of fluctuation in limb-volume status, fatigue, and the psychological aspects of combined treatments. Physical therapy emphasizing range of motion (ROM), strengthening, and functional activities is important for children with lower extremity sarcoma after limb-salvage surgery (62). Outcomes were similar for ambulation, stair climbing, employment, and psychological adjustment when comparing amputation to limb salvage as surgical management of sarcomas. Patients benefit functionally from gait training with prosthetic devices following amputation (63,64). Additionally, osteosarcoma patients who underwent amputation compared to limb salvage experienced similar socioeconomic outcomes, such as education, employment, and marital status at a 20 year follow-up; however, the most important factor for determining the quality of life in these patients was the functionality of the limb regardless of amputation or limb-salvage procedure (65,66). Conflicting studies argue that limb-salvage procedures appear to improve quality of life over amputation; however, this study did not directly evaluate functional status (67).