Bilateral Lower Limb Amputation: Prosthetic Management

Michael K. Carroll PhD, CPO, FAAOP(D)

Kevin Carroll MS, CP, FAAOP(D)

John Rheinstein CP, FAAOP(D)

Dr. Michael K. Carroll or an immediate family member serves as a paid consultant to or is an employee of Hanger; has stock or stock options held in Hanger; and serves as a board member, owner, officer, or committee member of the American Academy of Orthotists and Prosthetists and the National Commission on Orthotic and Prosthetic Education. Kevin Carroll or an immediate family member serves as a paid consultant to or is an employee of Hanger; has stock or stock options held in Hanger; and serves as a board member, owner, officer, or committee member of the American Academy of Orthotists and Prosthetists and the National Commission on Orthotic and Prosthetic Education. John Rheinstein or an immediate family member serves as a paid consultant to or is an employee of Hanger Clinic; has stock or stock options held in Abbott and Zimmer; and serves as a board member, owner, officer, or committee member of American Academy of Orthotists and Prosthetists.

This chapter is adapted from Carroll K, Rheinstein J, Richardson RW: Bilateral lower limb amputation: prosthetic management, in Krajbich JI, Pinzur MS, Potter BK, Stevens PM, eds: Atlas of Amputations and Limb Deficiencies: Surgical, Prosthetic, and Rehabilitation Principles, ed 4. American Academy of Orthopaedic Surgeons, 2016, pp 631-643.

ABSTRACT

Recent improvements in prosthetic technology and rehabilitation techniques have made useful function and independence possible for those with bilateral lower limb amputation. Use of the graduated length prosthetic protocol is essential for individuals with bilateral transfemoral amputation to ensure long-term prosthetic use. Goal setting, high expectations, and peer support are crucial for successful rehabilitation.

Because of the enhanced stability and reduced energy expenditure provided, microprocessor-controlled knees should be considered the medically necessary standard of care for bilateral transfemoral amputees who have the ability or potential to progress beyond indoor walking on level ground.

Introduction

Individuals with bilateral lower limb loss, and their rehabilitation teams, face a unique set of challenges which are much greater than those of patients with unilateral amputations.¹ Despite these challenges, recent advances in prosthetic technology and rehabilitation protocols have raised expectations for positive functional outcomes for many of these individuals. Improved outcomes include ambulation for many activities of daily living, stair navigation, hill descent, and running (Figures 1, 2 and 3). Each person presents differently because of their amputation levels, medical history, physical capabilities, and personality traits. Bilateral transfemoral and more proximal amputations require extensive prosthetic management and physical therapy for the person to regain mobility and independent function. If the knee joint can be preserved in at least one leg, better function and a shorter period of rehabilitation can be expected, however these cases still require close collaboration and planning within the rehabilitation team.² To maximize the likelihood of a successful outcome, a customized treatment plan must be developed for each patient’s specific needs and circumstances.

This chapter discusses the specific needs of patients with bilateral lower limb amputations, including postoperative care, identifying candidates for prosthetic use, appropriate prosthetic management, and effective protocols for successful rehabilitation. In addition,
factors that may affect progress, including motivation, peer support, and preparation for prosthetic use, are discussed. Most attention is given to treatment of those with bilateral transfemoral amputations because of their greater complexity when compared with more distal levels of amputation. Despite the small number of patients with bilateral lower limb loss relative to all amputations, there is an increasing amount of evidence and useful information available to guide clinical practice.³^,⁴

FIGURE 1 Photograph demonstrating learning to walk down a ramp with bilateral transfemoral prostheses. (Courtesy of Hanger Clinic, Austin, TX.)

FIGURE 2 Photograph demonstrating walking downhill using bilateral transfemoral prostheses. (Courtesy of Hanger Clinic, Austin, TX.)

FIGURE 3 Photograph demonstrating running using bilateral transfemoral prostheses without knee joints. (Courtesy of Hanger Clinic, Austin, TX.)

Causes of Bilateral Amputation

Most bilateral amputations are the result of medical complications from diabetes and peripheral vascular disease.⁵ Commonly, an individual experiences a series of lifesaving amputations, beginning with the loss of part or all of one foot. As the disease progresses, they may lose the contralateral foot after growing accustomed to ambulating with one amputated limb.⁶ A high likelihood of bilateral amputation and mortality exists in this cohort.⁶

Experience with a unilateral prosthesis is a good predictor of success as a bilateral prosthetic user despite the additional emotional distress.⁷ In our clinical experience, individuals facing the loss of their contralateral foot are best served when the second amputation is performed directly at the transtibial level to reduce the likelihood that multiple partial foot amputations will be needed. This approach allows patients to proceed with definitive rehabilitation rather than requiring recurrent hospitalization and rehabilitation admissions.

Bilateral amputations can also result from trauma, primarily war-related blast injuries.⁸ Advances in battlefield medicine have saved many lives, but survivors often have severe injuries, including multiple limb amputations.⁹ Heterotopic ossification is a difficult complication of traumatic injuries which makes prosthetic fitting challenging because of severe pain and frequent anatomical changes to the residual limb.¹⁰ Phantom pain, residual limb pain, and lower back pain are also widely reported.¹¹^,¹²

Diseases and septic infections such as strep, meningococcal septicemia, and necrotizing fasciitis are also causes of bilateral lower limb loss and may be accompanied by upper limb loss. These patients can be difficult to fit with prostheses because of challenges related to their residual limbs. To maintain maximal residual limb length in the face of a rapidly progressing disease, the shape of residual limbs is often irregular because of the removal of necrotic tissue. Large areas of skin graft and poor distal tissue coverage are common. The skin is often fragile and prone to breakdown and ulceration, even from normal forces generated by prostheses use. Multiple revision procedures and prosthetic sockets may be required until the residual limbs are stable. This is especially the case with children.¹³ Despite these challenges, patients who survive these devastating infections and diseases can lead functional productive lives¹⁴ (Figure 4).

Clinical Consideration

Effective treatment of individuals with bilateral lower limb amputation begins with a thorough physical, cognitive, and psychological assessment, setting goals, developing a plan, and frequent communication between members of the rehabilitation team. The team should include, but not be limited to, physiatrists, surgeons, physical therapists, prosthetists, social workers, caregivers, and payers. Patients and caregivers alike should be connected to peer support from others who have either undergone multiple lower limb loss or cared for someone who has experienced such loss. Goals are established considering each patient’s needs, future potential, and aspirations. Their motivation and determination to reach these goals are significant predictors of success.

Wound Care and Early Function

Irrespective of the level of amputation, surgical wounds must be managed with great care. Initial concerns are pain, wound healing, edema, contractures, and protection of the residual limb from falls or other impacts. Removable rigid dressings are the preferred method of
addressing these concerns and result in earlier prosthetic fitting and shortened acute hospital stays¹²^,¹⁵^,¹⁶ (Figure 5). Removable rigid dressings also provide patients with early experience managing a prosthetic device and learning self-care. Elastic compression garments can be used in conjunction with a removable rigid dressing to help control postoperative edema. Though ace wraps may be more readily available, use of shrinker socks or tubular elastic bandages are recommended as these decrease the likelihood of inconsistent pressure being applied to the limb.

FIGURE 4 A, Photograph of the lower limbs of a patient with a bilateral transtibial amputation secondary to meningococcemia. B, Photograph of the patient fitted with prostheses. Because the left knee is fixed at 45°, the prosthetic knee was placed under the patient’s residual limb to improve gait and sitting comfort. The patient is fully functional at work and in activities of daily living despite fragile skin.

FIGURE 5 Photograph of the AmpuShield (Hanger) postoperative protective removable rigid dressing. (Courtesy of Hanger Clinic, Austin, TX.)

Weight bearing should be restricted in patients with bilateral surgical wounds because they cannot offload either limb to achieve partial weight bearing. In patients with a recent amputation on one side and a functioning prosthesis on the other, partial weight bearing to the newly amputated side can be introduced based on the condition of the wound. If a newly performed amputation is at, or distal to, the transtibial level, the patient may be permitted to kneel with supervision during therapy. Kneeling allows the patient to assume an upright position for stretching, balance, and overall health.

The bilateral amputee may be unprepared for the change in their capabilities after the loss of the second limb. The individual’s ability to transfer to and from a wheelchair, and in and out of a car will be substantially reduced by the loss of a sound leg previously used for stabilization, pivoting, and balance. Physical therapy during the initial postoperative period should focus on performing safe transfer techniques to help maintain patient independence and prevent falls.¹⁷^,¹⁸ Developing strength and flexibility in the upper body is necessary for bilateral lower limb amputees, irrespective of prosthetic use. Those who intend to use prostheses also benefit from engaging the lower extremities, which may require an adaptive training program.¹⁹

Patients should be advised that even after therapy sessions are complete, their fitness program should continue for the rest of their lives. A daily exercise program that includes stretching, cardiovascular endurance, core strength, and balance is a crucial component of continued long-term success.²⁰^,²¹ It is especially important for individuals to maintain a healthy weight and blood glucose control. A person who is overweight will find it much more difficult to ambulate with bilateral prostheses, and weight fluctuations can adversely affect both prosthetic socket fit as well as prosthetic alignment. An effective weight control program should be instituted as early as possible to adjust diet for metabolic changes which follow amputation. Working with a dietitian is
encouraged for both users and nonusers of prostheses.

Wheelchair Selection

Most bilateral amputees initially require an appropriate wheelchair after surgery; some will need one for the rest of their lives. After becoming proficient with their prostheses, many patients can be rehabilitated to function with little to no use of a wheelchair.²² The authors currently care for many strong, active patients with bilateral transfemoral amputations, including some who are also missing arms, who are totally independent of a wheelchair.

Although a wheelchair-free life may be the preferred outcome, even individuals who achieve full-time prosthetic use may keep a wheelchair available for nighttime use, mobility over long distances, and times when they cannot wear their prostheses because of fitting or mechanical issues. Individuals who lack the strength, balance, cardiac reserve, endurance, or cognitive ability for full-time prosthetic use will need a wheelchair for some or most of their activities of daily living.²³^,²⁴ Those who use a manual wheelchair may benefit from a power-assist device that supplements their manual propulsion. The use of fully powered wheelchairs, however, should be discouraged unless necessary because they often result in deconditioning and weight gain.

After bilateral amputation, an individual’s center of mass when seated in a wheelchair shifts substantially. This shift is more pronounced at more proximal levels of amputation. Such individuals should be managed with wheelchairs that have specifically designed antitipping devices, with larger wheels placed more posterior to the seat area of the chair, reducing the potential for tipping over. The authors have seen many lower limb amputees with serious head and neck injuries, as well as damage to their healing residual limbs, caused when their standard wheelchairs tipped over backward. These severe but preventable occurrences are common. In one study of 18 patients with amputation, 14 experienced falls from their wheelchairs.²⁵ Patients should also be taught early in their rehabilitation how to transfer to a wheelchair from the floor.

While the Americans with Disabilities Act provides and enforces standards for wheelchair accessibility in the United States, in practice, access to certain establishments, nightclubs, or restaurants may still be inconvenient. In such situations, lower limb prosthetics allow access to those venues without the need for special services and attention. In other countries, the argument for choosing prostheses over a wheelchair is even more forceful. Many attractions worldwide are not wheelchair accessible. Cobblestone streets make wheelchair navigation uncomfortable, if not impossible.

Although ambulation with bilateral lower limb prostheses is challenging, the human spirit is capable of remarkable achievements under the most adverse conditions, and the challenges facing multiple-limb amputees are not insurmountable. Patients respond well to high expectations set by the rehabilitation team and by the example of other successful prosthesis users. Recent improvements in prosthetic technology, including advanced microprocessor knees (MPKs), allow the user to function in environments previously considered impossible, including oceans and swimming pools. In the future, further improvements in the capabilities of bilateral lower limb amputees are expected as technologic advances continue. These advances will be driven by researchers and clinicians who have an expansive vision of patients’ potential.

Prosthetic Care

Identifying Candidates for Prostheses

Determining suitability for prosthetic use is based on a thorough understanding of each patient’s physical condition, cardiac fitness, goals, level of motivation, environmental conditions, as well as their cognitive ability.²⁶^,²⁷ Although bilateral prosthetic use demands higher energy expenditure than that required by able-bodied individuals (150% to 188%) or those with a unilateral prosthesis (130% to 160%), every bilateral amputee should be evaluated to determine the potential for prosthetic care.²⁸^,²⁹^,³⁰ Prosthetic use should only initially be ruled out for patients with severe irreversible medical conditions or profound cognitive deficits. More than one evaluation may be indicated because a patient’s conditions can change. For example, patients who are weak as a result of disease, surgery, or extended sitting because of protracted nonsurgical treatment to preserve a diseased limb, often gain strength and progress to prosthetic use with regular physical therapy.

Patients who may not show initial potential for prosthetic use can be challenged to achieve milestones for strength, flexibility, and endurance. Once improvement is shown, preparatory prostheses can be provided. The ability to kneel in an upright position on both knees is a positive indicator for prosthesis use among patients following bilateral transtibial amputation. The Amputee Mobility Predictor (AMPNoPro), an assessment tool designed to evaluate the skills required for successful prosthetic ambulation, can be used to help determine potential functional capabilities.⁴

The rate of recovery and level of independence achieved depend largely on each individual, their unique physical and psychological makeup, as well as environmental factors such as family support and living arrangements.³¹ Patients generally can be classified into one of four groups: nonusers, who do not use a functional prosthesis at all; partial users, who have one or two prostheses for transfers or wheelchair propulsion; mixed users, who use both prostheses and a wheelchair (wheelchairs are used for long distances); and full-time users independent of a wheelchair (younger, healthier individuals who are expected to progress rapidly unless there are physical or cognitive comorbidities).³²

Prosthesis Nonusers

In most cases, patients with irreversible medical complications, insufficient cardiac reserves, severe weakness, or nonhealing wounds, as well as those who lack motivation or cognitive ability, are not candidates for prostheses.²⁷ Some
bilateral amputees immediately recognize that they cannot benefit from prostheses. Others may be highly motivated, but have comorbidities that preclude prosthesis use. Some may be investigating the possibility of using prostheses because of pressure or encouragement from their families.

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