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Section 3. Surgery and Rehabilitation
Chapter 29. Rehabilitation For Specific Problems
Topics:    Introduction | Heart Disease | Stroke | Hip Fracture | Leg Amputation

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Leg Amputation

Before amputation, the physician describes to the patient the extensive postsurgical rehabilitation program that will be needed. Psychologic counseling may be indicated. The rehabilitation team and the patient decide whether a prosthesis or a wheelchair will be needed.

Immediately after surgery, measures are taken to prevent secondary disabilities, especially contractures. Flexion contracture of the hip or knee, which may develop rapidly after surgery, can make the fitting and use of a prosthesis difficult. Exercises for general conditioning, stretching of the hip and knee, and strengthening of all extremities are started as soon as the patient is medically stable. Endurance exercises may be indicated. Elderly amputees should begin standing and balancing exercises with parallel bars as soon as possible.

Unilateral amputation: Ambulation requires a 10 to 40% increase in energy expenditure after below-the-knee amputation and a 60 to 100% increase after above-the-knee amputation. To compensate, elderly amputees generally walk more slowly. Gait abnormalities in elderly amputees who can walk safely are not of concern and are often avoidable with a well-fitting prosthesis and good rehabilitation.

Functional prognosis after below-the-knee amputation differs greatly from that after above-the-knee amputation. Elderly patients who have had a below-the-knee amputation and are fitted with a prosthesis usually become functionally ambulatory. Elderly patients who have had an above-the-knee amputation may not have the energy and skills required to deal with the weight of the above-the-knee prosthesis and to control the knee joint.

Bilateral amputation: Amputation of both legs is not unusual for diabetic patients or patients with peripheral vascular disease. As with unilateral amputation, functional prognosis depends on whether the amputations are above or below the knee. Bilateral below-the-knee amputees with well-fitting prostheses may be able to walk without canes or crutches. Bilateral above-the-knee amputees with prostheses probably can walk only with two canes or crutches. However, most elderly patients with bilateral above-the-knee amputations do not have the necessary energy or strength to ambulate with prostheses.

For patients who have had a below-the-knee amputation first and can ambulate independently with a prosthesis, ambulation with a second prosthesis is probably possible regardless of the level of the second amputation. Amputees with one below-the-knee and one above-the-knee amputation use the former as the functional leg; a manual knee lock may sometimes be required on the above-the-knee prosthesis.

Regardless of the level of the amputations, walking distance is generally limited, and a wheelchair may be needed, especially outdoors and for long distances.

Stump Conditioning and Prostheses

Stump conditioning promotes the natural process of stump shrinking that must occur before a prosthesis can be used. After only a few days of conditioning, the stump may have shrunk greatly. An elastic stump shrinker or elastic bandages worn 24 hours/day can help taper the stump and prevent edema. The stump shrinker is easy to apply, but bandages may be preferred because they better control the amount and location of pressure. However, application of elastic bandages requires skill, and the bandages must be reapplied whenever they become loose.

Early ambulation with a temporary prosthesis enables the amputee to be active, accelerates stump shrinkage, prevents flexion contracture, and reduces phantom limb pain. The socket of the pylon, which is made of plaster of paris (calcium sulfate hemihydrate), should fit the stump snugly. Various temporary prostheses with adjustable sockets are available. A patient with a temporary prosthesis can start ambulation exercises on the parallel bars and progress to walking with crutches or canes until a permanent prosthesis is made.

The permanent prosthesis should be lightweight and meet the needs and safety requirements of the patient. If the prosthesis is made before the stump stops shrinking, adjustments may be needed to satisfy the patient and to produce a good gait pattern. Therefore, manufacture of a permanent prosthesis is generally delayed a few weeks to allow shrinkage of the stump. For most elderly patients with a below-the-knee amputation, a patellar tendon-bearing prosthesis with a solid-ankle, cushion-heel foot and suprapatellar cuff suspension is best. Unless patients have special needs, a standard below-the-knee prosthesis with thigh corset and waist belt is not prescribed because it is heavy and bulky. For above-the-knee amputees, several knee locking options are available according to the patient's skills and activity level.

Care of the stump and prosthesis: Patients must learn to care for their stump. Because a leg prosthesis is intended only for ambulation, patients should remove it before going to sleep. At bedtime, the stump should be inspected thoroughly (with a mirror if inspected by the patient), washed with mild soap and warm water, dried thoroughly, then dusted with talcum powder. If the skin of the stump is too dry, lanolin or petrolatum may be applied. If the stump sweats excessively, an unscented antiperspirant may be applied. If the skin is inflamed, the irritant must be removed immediately, and talcum powder or a low-potency corticosteroid cream or ointment applied. If the skin is broken, the prosthesis should not be worn until the wound has healed.

The stump sock should be changed daily, and mild soap may be used to clean the inside of the socket. Standard prostheses are neither waterproof nor water-resistant. Therefore, if even part of the prosthesis becomes wet, it must be dried immediately and thoroughly; heat should not be applied. For elderly persons who swim or prefer to shower with a prosthesis, a prosthesis that can tolerate immersion can be made.

Complications

The most common complaint is stump pain. Mild to severe pain is felt when the stump is palpated or when a pylon or prosthesis is used. Stump pain is localized and differs from phantom limb pain, from which it must be differentiated. An ill-fitting socket, which may be due to small socket size, an edematous stump, or weight gain, may cause stump pain. However, the most common causes are an amputation neuroma or spur formation at the amputated end of the bone. A neuroma is usually palpable. A spur may be palpable or seen on x-rays. For a neuroma, daily ultrasound treatments for 5 to 10 days are most effective. Alternatives include injection of corticosteroids or analgesics into the neuroma or the surrounding area, use of cryotherapy, or continuous tight bandaging of the stump. Surgical resection of the neuroma often has disappointing results. The only effective treatment of a spur is surgical resection.

Phantom limb pain is more likely to occur if the patient had a painful condition before amputation or if pain was inadequately controlled intraoperatively and perioperatively. Treatments such as simultaneous exercise of both legs, massage of the stump, percussion of the stump with fingers, use of mechanical devices (eg, a vibrator), and ultrasound are effective. Drugs (eg, tricyclic antidepressants, carbamazepine) may help.

Phantom limb sensation is a painless awareness of the amputated limb, sometimes accompanied by mild tingling. Most amputees experience this sensation, which may last several months or years but usually disappears without treatment. Frequently, amputees sense only part of the missing limb, often the foot, which is the last phantom sensation to disappear. Some amputees can even describe the position of the foot, which is often related to its position at the time of amputation. Phantom limb sensation is not harmful; however, amputees, without thinking, commonly attempt to stand with both legs and fall, particularly when they wake at night to go to the bathroom.

Follow-up

Follow-up examinations are performed every 3 to 6 months for the first 2 years for patients who successfully complete a prosthetic rehabilitation program and return to the community. The stump usually continues to shrink with use. An adequate fit of the prosthesis can be achieved by adding layers of socks, although eventually a new socket is needed. Because of continuous use, components of the prosthesis may deteriorate, sometimes altering the gait.

At each visit, the circulatory status of the unaffected leg is checked. Many patients who had a below-the-knee amputation due to vascular disease eventually require an above-the-knee amputation.

An amputee wheelchair, which has wider wheel axles to compensate for the absence of leg weight and to prevent tilting, is eventually needed by all elderly amputees, even those who use a prosthesis. These wheelchairs are needed, for example, when using a prosthesis is bothersome (eg, at night) or impossible (eg, due to the condition of the stump) or when traversing long distances. Properly maintained, wheelchairs last 5 to 10 years.

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