The main causes of limb amputation are
Vascular disease (particularly from diabetes Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more and peripheral arterial disease Peripheral Arterial Disease Peripheral arterial disease (PAD) is atherosclerosis of the extremities (virtually always lower) causing ischemia. Mild PAD may be asymptomatic or cause intermittent claudication; severe PAD... read more )
Cancer
Injury (eg, motor vehicle or work-related accident, military combat)
Congenital anomaly
In the United States, slightly over 0.5% of people are currently living with the loss of a limb, and approximately 500 amputations are done each day (1 References A limb prosthesis is an artificial limb that replaces a missing body part. The main causes of limb amputation are Vascular disease (particularly from diabetes and peripheral arterial disease)... read more ). This percentage is likely to increase because of the aging of the population and the associated increase in the incidence of diabetes mellitus and vascular disease.
Goals
Goals of prosthesis fitting include comfort, stability while standing and walking, and enabling performance of various daily activities. Prostheses are comprised of a custom interface, socket, and a wide variety of other components that serve different goals ranging from simple mobility to high-impact activities. Recent advances in cushioning materials, prosthetic socket design, and foot, ankle, knee, hand, wrist, and elbow component technology have significantly improved comfort and function.
Highly motivated, otherwise healthy people with a prosthesis can accomplish many extraordinary feats (eg, go skydiving, climb mountains, complete triathlons, fully participate in sports, or return to demanding jobs or to active duty in the military). Whether a prosthesis is used only for basic mobility or for more demanding activities, it can provide profound psychologic benefits.
Successful prosthesis use depends on the following:
Patient's underlying medical conditions and physical and cognitive capabilities
Anatomy (eg, length and condition of the residual limb)
Fit of the prosthesis socket (eg, comfort and stability)
Function and biomechanical efficiency of the components of the prosthesis
Prosthesis fitting and the patient making the physical and mental adjustments necessary to function with the prosthesis are a protracted and challenging process. Not all patients are candidates for all types of prosthesis.
Amputation rehabilitation team
Early rehabilitation facilitates recovery and future success in using a prosthesis (2 References A limb prosthesis is an artificial limb that replaces a missing body part. The main causes of limb amputation are Vascular disease (particularly from diabetes and peripheral arterial disease)... read more ). When possible, rehabilitation begins prior to the amputation and in nonelective cases, as early as the first postoperative day.
Success is most likely when an interdisciplinary clinical team works with the patient. The composition of the team varies depending on the patient’s needs. At a minimum, core members include the surgeon, prosthetist, and therapist. Prosthetists evaluate the patient and design, fit, fabricate, and provide lifetime follow-up care to maintain the prosthesis and provide advice and instruction on care. For more complex cases, the team could also include a physiatrist, physical therapist, occupational therapist, social worker, psychologist, and family members.
Amputations
An entire limb or part of one may be amputated. Decisions regarding amputation level are based first on tissue viability and the ability to maintain adequate circulation in the residual limb. The goal is to remove devitalized, ischemic, or infected tissues, and preserve functional length consistent with healing, prosthetic technology, and successful rehabilitation. Other important surgical considerations include closing bone marrow, having adequate muscular covering over terminal bones, and providing an insertion for cut muscles. Adequate muscular covering improves load bearing, which in turn helps prevent osteoporosis Osteoporosis Osteoporosis is a progressive metabolic bone disease that decreases bone mineral density (bone mass per unit volume), with deterioration of bone structure. Skeletal weakness leads to fractures... read more in the residual bone, which can occur very rapidly following amputation. Having an insertion allows muscular contraction, which improves power in the limb, increases arterial inflow, decreases venous stasis, and decreases risk of neurologic symptoms and pain.
The amount and quality of bone, muscle, nerve, and skin are critical to successful prosthesis intervention. The most technologically sophisticated prosthesis cannot overcome deficiencies related to suboptimal surgical technique. Conversely, an optimal surgical procedure will not have a good outcome with an ill-fitting, inefficient prosthesis.
Amputation levels are somewhat standardized:
Upper limb amputations include
Partial hand: Digit, metacarpal-phalangeal, carpal-metacarpal
Wrist disarticulation
Transradial
Elbow disarticulation
Transhumeral
Shoulder disarticulation and forequarter amputation
Lower limb amputations include
Partial foot: Ray resection, transmetatarsal
Tarsometatarsal (Lisfranc)
Transtarsal (Chopart )
Transcalcaneal (Boyd)
Ankle disarticulation
Transtibial
Knee disarticulation
Transfemoral
Hip disarticulation and hemipelvectomy
Because different socket designs may benefit from slight changes in surgical technique, preoperative consultation between surgeon and prosthetist is useful.
Preparing the patient
Preoperative preparation Preparing for a Limb Prosthesis When amputation is elective, certain preparatory measures can help optimize recovery. It is important to educate the patient and family members as early as possible regarding the necessity of... read more of the patient and family is important, particularly education about the necessity of amputation and the need for active patient commitment and participation in the entire process. A visit from a mature person with a similar amputation and characteristics can be highly beneficial. Above all, the entire orientation should be realistic. Ranges of likely outcomes, rather than the best possible outcome, should be communicated.
Performance-based measures, such as the Amputee Mobility Predictor, can help determine the likely level of function (3 References A limb prosthesis is an artificial limb that replaces a missing body part. The main causes of limb amputation are Vascular disease (particularly from diabetes and peripheral arterial disease)... read more ).
Premorbid medical conditions, including inadequate nutrition, should be alleviated as much as possible. Poorly controlled diabetes and cardiopulmonary disease can interfere with healing and/or rehabilitation. Smoking also is detrimental to healing, so smoking cessation Smoking Cessation Most people who smoke want to quit and have tried doing so with limited success. Effective interventions include cessation counseling and pharmacologic treatment, such as varenicline, bupropion... read more measures are important.
Postoperative management and complications
Immediate postoperative management includes measures to
Maintain range of motion to prevent joint contractures
Maintain or increase strength and general conditioning
Manage edema (eg, by compression)
When recovery permits, patients should begin to desensitize the terminal residual limb by massage, tapping, vibration, and progressive load-bearing. Healthy eating habits should be encouraged.
Prosthesis fitting Fitting the Prosthesis There are many options for limb prostheses, but after a functional evaluation results in a treatment plan, the fitting process typically follows the same steps regardless of which limb prosthesis... read more can begin when the surgical wound is sufficiently healed, residual-limb fluid volume has stabilized to an acceptable level, the patient has sufficient general strength and joint range of motion, and medical release is given—usually 7 to 10 weeks post-amputation.
The residual limb will undergo considerable morphologic changes for 6 to 18 months following amputation. Preparatory/temporary prostheses are fitted until the residual limb stabilizes, at which time a definitive prosthesis is provided. A temporary prosthesis allows the patient to become accustomed to a prosthesis and, for lower limb amputation, to stand and bear weight. Several socket replacements may be necessary before residual-limb fluid volume stabilizes and definitive prosthesis procedures can begin.
Gait training for a person with a lower limb amputation is intended to improve spatio-temporal awareness and lower limb joint kinematics and minimize the amount of energy required to ambulate with the prosthesis (see also Leg Amputation Rehabilitation Leg Amputation Rehabilitation Before amputation, the physician describes to the patient the extensive postsurgical rehabilitation program that is needed. Psychologic counseling may be indicated. The rehabilitation team and... read more ).
Complications typically include persistent pain in the residual limb Pain in the Residual Limb Approximately 60% of individuals with an amputation have post-amputation pain in the residual limb, which can severely limit function, impair quality of life, and significantly impede rehabilitation... read more , severe hypersensitivity (both superficially and in deeper tissues), circulatory insufficiency, skin breakdown, and edema of the residual limb Edema of the Residual Limb Even after the residual limb matures 18 to 24 months post amputation, edema can still occur. Having a well-fitting prosthesis socket is the best way to maintain a consistent residual-limb size... read more . These may be due to a problem with the residual limb or with the prosthesis and/or socket.
References
1. Ziegler-Graham K, MacKenzie EJ, Ephraim PL, et al: Estimating the prevalence of limb loss in the United States: 2005 to 2050. Arch Phys Med Rehabil 89(3):422-429, 2008. doi:10.1016/j.apmr.2007.11.005
2. Webster JB, Crunkhorn A, Sall J, et al: Clinical Practice Guidelines for the Rehabilitation of Lower Limb Amputation: An Update from the Department of Veterans Affairs and Department of Defense. Am J Phys Med Rehabil 98(9):820-829, 2019. doi:10.1097/PHM.0000000000001213
3. Gailey RS, Roach KE, Applegate EB, et al: The Amputee Mobility Predictor: an instrument to assess determinants of the lower-limb amputee's ability to ambulate. Arch Phys Med Rehabil 83(5):613-27, 2002. doi: 10.1053/ampr.2002.32309