Key points

Introduction

In 2005 there were an estimated 1.6 million individuals in the United States living with limb loss. This number has been projected to more than double by 2050 to 3.6 million, making an understanding of management of the individual with amputation essential for the physiatrist. In developed nations, disease is the leading cause for amputation, with the incidence of major amputation in patients with diabetes being approximately 10-fold that of nondiabetic dysvascular patients in certain populations. As such, many of the complications after amputation may, in fact, be attributable to the underlying disease process and not dissimilar to issues that led to the initial amputation. Other complications are potential sequelae of amputations of nearly any cause. Treatment, therefore, may not vary significantly among different amputation populations. This article highlights common complications after amputation and discusses management strategies for each. As with many disease processes, the multidisciplinary approach with coordination of care among the physiatrist, therapists, nursing staff, psychologist, and other specialists proves to be most effective and rewarding in optimal management of patients with amputation.

Introduction

In 2005 there were an estimated 1.6 million individuals in the United States living with limb loss. This number has been projected to more than double by 2050 to 3.6 million, making an understanding of management of the individual with amputation essential for the physiatrist. In developed nations, disease is the leading cause for amputation, with the incidence of major amputation in patients with diabetes being approximately 10-fold that of nondiabetic dysvascular patients in certain populations. As such, many of the complications after amputation may, in fact, be attributable to the underlying disease process and not dissimilar to issues that led to the initial amputation. Other complications are potential sequelae of amputations of nearly any cause. Treatment, therefore, may not vary significantly among different amputation populations. This article highlights common complications after amputation and discusses management strategies for each. As with many disease processes, the multidisciplinary approach with coordination of care among the physiatrist, therapists, nursing staff, psychologist, and other specialists proves to be most effective and rewarding in optimal management of patients with amputation.

Musculoskeletal complications

It is estimated that 20% of people with amputation underwent amputation early in life, and therefore, may have to deal with the adverse sequelae of long-term altered postural and gait mechanics, relative inactivity, muscular imbalances, and surgical complications. These complications include joint contracture, early degenerative joint disease and overuse injury on the intact limb, back pain, osteopenia/osteoporosis, fracture, and disuse atrophy. Many of these complications can be avoided with diligent care and patient education, which should begin immediately in the postoperative period, and be carried over into the remainder of the patient’s life.

Joint contracture is a common occurrence after lower limb amputation for multiple reasons, with many patients with transtibial amputation developing knee flexion contracture and/or hip flexion contracture, and those with transfemoral amputation developing hip flexion and abduction contracture. First, because patients are generally less active immediately after their amputations and spend most of their time resting in either a seated or a lying position, it is easy for hip and knee flexion contractures to develop because there are very few resting postures where these joint are positioned in anything other than the flexed position. Second, the muscle imbalance created by the amputation itself can predispose the involved joint to developing contracture. It has been found that cleaved muscles after transfemoral amputation can atrophy 40% to 60%, while intact muscle in the amputated limb can still atrophy up to 30%. Loss of hip adductor strength can predispose to hip abduction contracture, while avoiding fixation of the iliotibial tract in an attempt to prevent hip abduction contracture can predispose to hip flexion contracture as the hip extension torque of the gluteus maximus is decreased.

Both performing and instructing the patient in range-of-motion exercises is paramount in re-creating a natural and efficient gait pattern, and prevention of skin breakdown as well as pain in the prosthesis. For the patient with transtibial amputation, the prescription of a residual limb support allows the knee of the amputated limb to be positioned in extension while the patient is seated in his or her wheelchair. Immediate postoperative rigid dressings (IPORD), immediate postoperative prostheses (IPOP), as well as bi-valved casts can aid in prevention of joint contracture and have the added advantages of protecting the operative wound and controlling postoperative limb swelling. However, they require both skill and time to create, need to be remade as the limb reduces in size, and in the case of the IPORD and IPOP, do not allow for easy viewing of the surgical incision. Once contracture has already developed, serial casting may be used to stretch the joint, while those cases refractory to conservative measures may require surgical management.

Altered gait and postural patterns in the lower limb amputee can come from learned walking patterns to compensate for weakness, joint contracture, a sensation of instability, improper prosthetic fit, or from any combination of the above. Up to 23% difference in ground reaction force has been found between the intact and amputated limb, and persons with amputation also typically spend more time on their intact limb. With increased forces on the joints of the intact limb there is a greater prevalence of knee pain and radiographic evidence of patellofemoral osteoarthritis in the intact limb. Asymmetry in gait and increased dependence on proximal musculature have also been associated with a 3- to 6-fold incidence of osteoarthritis of both hips in patients with lower limb amputation, with a nearly 3-fold incidence of hip osteoarthritis in the amputated as compared with the intact limb, while decreased forces through the prosthetic limb may contribute to osteoporosis/osteopenia and fracture due to low bone mineral density. With respect to low back pain, hip flexion contracture requires hyperlordosis of the lumbosacral spine to maintain upright posture and may cause or exacerbate preexisting low back pain. Similarly, limb length asymmetry due to suboptimal prosthetic fitting or inadequate fit within the prosthetic socket can also cause gait and postural asymmetry as well as pain by increasing the lateral tilt of the pelvis in the frontal plane, and therefore, requiring a compensatory scoliosis.

Overuse of the intact limb in upper limb amputees is also associated with a higher incidence of self-reported musculoskeletal pain in the upper limb amputee. Common areas of pain in the upper limb amputee were in the neck/upper back (57%) and shoulders (58.9%). Interestingly, prosthesis wear was not found to affect this pain.

In addition to range-of-motion exercises, particular attention should be paid to strengthening, not only of the proximal muscles of the amputated limb, but also of the intact limb. In the patient with transtibial amputation, knee and hip extensor strength is essential for maintaining knee stability during stance, while in those with transfemoral amputation focus should be placed on hip girdle and core strengthening. It is equally important to coach patients on proper gait mechanics, focusing on establishing symmetry in stance times and step lengths between the intact and amputated limbs and avoiding unnecessary compensatory strategies, which may prove to be energy costly and cause undue stresses to muscles and joints of the intact limb. Finally, fit and alignment should be optimized to ensure proper standing and walking posture and limb length symmetry (in patients with preexisting limb length asymmetry, this may not be warranted because matching limb lengths may, in fact, prove uncomfortable due anatomic and postural compensations made over time). For the patient with upper limb amputation, focus should be placed on shoulder girdle strengthening and scaption exercises, as these motions are frequently used for control of the upper limb prosthesis, particularly in body-powered designs.

Heterotopic ossification seems to be a common occurrence, particularly after traumatic amputation where the amputation site occurs within the initial zone of injury. However, not all instances are problematic. Those that are may be treated conservatively with adjustments to the prosthetic socket to provide pressure relief to the area of bony prominence. Approximately 80% of patients with radiographic evidence were found to either be asymptomatic or able to be managed successfully nonoperatively. For cases refractory to conservative measures, surgical excision can be performed with good success rates.

Dermatologic considerations

Disruption of skin integrity is a major causative factor for amputation, especially in patients with diabetes. Likewise, patients with amputation may be at increased risk for revision amputation or amputation of the contralateral limb if the protective barrier offered by the skin is not maintained. Up to 41% of persons with lower limb amputation experience skin problems on their residual limb, with the most commonly reported issues being wounds, abscesses, and blisters. Dermatologic issues may be secondary to surgical complications, repetitive injury, or reaction to occlusion of the skin. Wound dehiscence is a major complication that requires immediate referral back to the surgeon. Wound dehiscence most commonly occurs from local trauma to the area of the healing surgical incision. Care must be taken to avoid trauma or distraction of the skin edges as the wound heals. In a patient demonstrating impulsive or unsafe behavior, the incision may be protected by the fabrication of an IPORD/IPOP or a bivalve cast. A bivalve cast also may offer a measure of comfort to patients whose anxiety about their healing limb limits their ability to perform transfers or activities of daily living independently. Residual limb shaping begins shortly after amputation to control postoperative swelling and prepare the limb for eventual fitting with a prosthesis. Until enough healing has occurred for wound closure with either staples or sutures to be safely removed, the application of a residual limb shrinker is avoided, because shear forces from the shrinker could pull apart the healing skin edges and either prevent wound healing or dehisce the wound. Once wound closure devices are removed, application of a shrinker is generally considered safe. Sutures or staples are generally maintained longer in patients with diabetes, given their predisposition to a more protracted wound healing course.

The skin of the residual limb should be monitored closely by both the clinician and the patient, especially in the prosthetic training period, as excessive pressure or shear within the prosthetic socket can very quickly lead to skin breakdown. These pressures can be caused by suboptimal socket fit and/or prosthetic alignment, and therefore, the patient must be observed during gait and standing (for lower limb amputees) as well as at the time of donning. A discussion of specific gait deviations and prosthetic alignment is beyond the scope of this article, but knowledge of how each deviation may cause skin breakdown and how to correct it is important in prosthetic management. Generally speaking, socket fit should allow for displacement of pressure over a greater surface area, taking care to offload pressure from intolerant areas (eg, hamstrings, tibial crest, tibial tuberosity) and preferentially load more tolerant areas (popliteal area, patellar tendon). It is a common misconception among patients that padding should be added to areas of soreness. Adding padding to areas of excessive pressure will only serve to increase focal pressure and increase the risk of skin breakdown. Instead, padding should be added around the area of pressure (eg, “keying in” the tibial crest by placing padding medial and lateral to it) to offload the area of prominence successfully.

Dermatologic conditions related to occlusion can be challenging to manage, because in the patient using a prosthesis, much of the day is spent with the residual limb covered. Hyperhidrosis is a common complaint with prosthetic wear (23%–70% of amputees ) and can become problematic if persistent maceration of the skin causes breakdown. Conservative treatments include use of either an over-the-counter or prescription medication, changing from a nonbreathable gel liner and suspension system to a more breathable system (eg, changing from a total surface bearing socket with gel liner to a patellar tendon bearing socket with a pelite insert). Botulinum toxin has been shown to have good effect for hyperhidrosis refractory to the above management strategies. Skin eruptions (eg, folliculitis) can be reduced with optimal skin hygiene and liner care. Daily washing of the residual limb with mild soap and water is recommended, and daily cleaning can be performed with either mild soap and water or alcohol, depending on the liner type. For those patients in whom inflammation has developed into superficial abscess, incision and drainage and treatment with antibiotics are warranted. Dermatitis may be a response to the liner material and may warrant changing the type of liner used; however, anecdotally, use of an antihistamine cream has offered relief to some patients who have experienced pruritus without erythema or other evidence of frank contact dermatitis.

Monitoring of skin on the intact limb is equally important to skin care for the residual limb. In the dysvascular patient with diabetes, xeroderma, or dry skin, is a common occurrence because of impairment of cutaneous glands. Care should be taken to keep the skin adequately moisturized in areas that tend to get dry easily (eg, the lower legs), whereas areas prone to maceration (eg, between the toes) should be kept dry with the use of material such as lambs wool, which serves to ventilate and dry out the skin. Regular skin hygiene and skin checks should be used to maintain skin integrity. Maintaining skin integrity may be difficult for the patient with impaired mobility and flexibility or impaired vision (eg, the patient with diabetic retinopathy). Skin checks can be facilitated with the use of long-handled mirrors, with digital pictures from a camera phone, or by training a caregiver in proper skin inspection. As excessive shear and pressure from the prosthetic socket can cause callusing and breakdown, so can improperly fitting shoe wear on the intact foot. Shoes with an accommodating toe box help to reduce pressure and callusing over bony prominences, while pressure relieving buildups (eg, metatarsal bars/pads) and toe rockers may be necessary to reduce local pressures in the foot for those with joint motion restriction. Orthopedic or “diabetic” shoes generally do very well at accomplishing adequate pressure relief, but are often cost prohibitive if not covered by insurance. In these instances, it is recommended that the patient buy shoes from a specialty shoe store, where sales representatives are generally more knowledgeable and may aid in making the appropriate foot wear choice.