eMedicine Specialties > Orthopedic Surgery > Foot & Ankle

Amputations of the Lower Extremity

Author: Janos P Ertl, MD, Clinical Assistant Professor, Department of Orthopedic Surgery, University of California at Davis; Director of Amputee Clinic, Chief of Orthopedic Trauma, Kaiser Hospital
Coauthor(s): William Ertl, MD, Clinical Assistant Professor, Department of Orthopedics, University of Oklahoma; James W Pritchett, MD, FACS, Clinical Associate Professor of Orthopedic Surgery and Sports Medicine, University of Washington School of Medicine
Contributor Information and Disclosures

Updated: Mar 7, 2008

Introduction

Lower-extremity amputation is one of the oldest known surgically performed procedures.^1,2 The original surgical principles as described by Hippocrates remain true today. Refinements of surgical technique such as hemostasis, anesthesia, and improved perioperative conditions have occurred, but only relatively small technical improvements have been made.

Amputation is still often viewed as a failure of treatment. The responsibility for performing an amputation may even fall on the most junior member of the surgical team. Whatever the reason for performing an extremity amputation, it should not be viewed as a failure of treatment. Amputation can be the treatment of choice for severe trauma, vascular disease, and tumors. Patients and family members must be aware of their options and have realistic expectations of surgical outcomes in order to make informed decisions regarding amputation.

For excellent patient education resources, visit eMedicine's Diabetes Center. Also, see eMedicine's patient education articles Diabetic Foot Care, Gangrene, and Electric Shock.

Related eMedicine topic:
Digital Amputations

Related Medscape topics:
Resource Center Diabetic Microvascular Complications
Resource Center Vascular Surgery
Resource Center Wound Management

History of the Procedure

Amputation surgery is an ancient procedure dating back to prehistoric times. Neolithic humans are known to have survived traumatic, ritualistic, and punitive rather than therapeutic amputations. Cave-wall hand imprints have been found that demonstrate the loss of digits. Unearthed mummies have been found buried with cosmetic replacements for amputated extremities.

The earliest literature discussing amputation is the Babylonian code of Hammurabi, inscribed on black stone, from 1700 BCE, which can be found in the Louvre. In 385 BCE, Plato's Symposium mentions therapeutic amputation of the hand and the foot. Hippocrates provided the earliest description of therapeutic amputation in De Articularis for vascular gangrene. Hippocrates describes amputation at the edge of the ischemic tissue, with the wound left open to allow healing by secondary intent.

The main risks described in the early history of amputation surgery were hemorrhage, shock, and sepsis. Before the discovery of anesthesia, the procedure itself was quite difficult. The patient would be held down by a number of assistants and be given alcohol (usually rum). The patient would essentially be awake and aware during the procedure.

A brief outline of the history of amputation is as follows^1,2 :

• 385 BCE – Plato's Symposium, Hippocrates's De Articularis
• 1st century CE – Use of cautery for large vessels (Celsus), first mention of ligatures, removal of gangrenous extremity through the viable tissue edge with a bone cut shorter than the soft tissues
• 1528 – Advent of gunpowder and increase in extremity injuries
• 1529 - Ambroise Pare – ligature introduced, also thick ligature used as a tourniquet
• 1588 – William Cloves – first successful above-knee amputation
• 16th century – Botallus and Fabricius Hildanus – supposed invention of the tourniquet
• 1674 – Morel – Battle of Borodino; tourniquet
• 1679 – Younge and Lowdham – introduction of local flaps for wound closure (animal bladders used previously)
• 1718 – Petit – tourniquet again described
• 1781 – John Warren – first successful shoulder amputation
• 1812 – Dominique Jean-Larrey – removal of 200 limbs in a 24-hour period at the Battle of Beresina; also, disarticulation of 11 shoulders in 24-hour period, with 9 complete recoveries
• 1806 – Walter Brashear – first successful hip joint amputation
• 1837 – Liston – routine use of flap closure
• 1825 – Nathan Smith – through-knee amputation described
• 1842 – Sixty-two percent mortality rate for through-thigh amputation
• 1857 – Gritti – patella placed over the end of the transected femoral condyles.
• 1858 – Earliest surviving prosthesis (Etruscan) discovered in Capri
• 1870 – Stokes and Grittis procedures modified (ie, Gritti-Stokes amputation)
• 1873 – Eschmarch (student of Langenbeck) – rubber bandage used, rendering amputation bloodless, reproducible, and safer; limitation of use described per procedure, as well as avoidance of use on infected limbs
• 1890 – Jaboulay and Girard – first successful hindquarter amputation
• 1920 – Ertl – introduction of osteomyoplastic technique and the flexible bone graft for both transfemoral and transtibial levels
• 1943 – Major General Norman T. Kirk – indicated guillotine amputations in war setting should be completed as distal as possible and completed later under calmer conditions
• 1946 – Suction socket and patellar tendon-bearing prosthesis
• 1960-1980 – Recommendation to salvage knee in vascular amputations

Related Medscape topic:
Resource Center Surgical Blood Management

Problem

One of the greatest difficulties for a person undergoing amputation surgery is overcoming the psychological stigma that society associates with the loss of a limb. Persons who have undergone amputations are often viewed as incomplete individuals. Following the removal of a diseased limb and the application of an appropriate prosthesis, the patient can resume being an active member of society and maintaining an independent lifestyle.

Although a diseased limb can be removed quite readily, resolving the problem of the extremity, the care does not end there. The surgery must be performed well to ensure that the patient is able to wear a prosthesis comfortably. Knee joint salvage enhances rehabilitative efforts and decreases the energy expenditure required for ambulation.³

The patient must learn to walk with a prosthesis, apply and remove the prosthesis, care for the prosthesis, monitor the skin and the presence of any pressure points, ambulate on difficult terrain, and use the commode at night. Because of the complexity of these issues, the treatment team should include the surgeon, the primary care physician, a physical therapist, a prosthetist, and a social worker.^4,5

Frequency

In the United States, 30,000-40,000 amputations are performed annually. There were an estimated 1.6 million individuals living with the loss of a limb in 2005; these estimates are expected to more than double to 3.6 million such individuals by the year 2050.⁶

Most amputations are performed for ischemic disease of the lower extremity. Of dysvascular amputations, 15-28% of patients undergo contralateral limb amputations within 3 years. Of elderly persons who undergo amputations, 50% survive the first 3 years.

In 1965, the ratio of above-knee amputations to below-knee amputations was 70:30. A quarter century later, the value of retaining the knee joint and the greater success in doing so was appreciated, so the ratio became 30:70.

Etiology

Lower-extremity amputations may be performed for the following reasons^1,2 :

• Peripheral vascular disease (PVD)^7,8,9,10,11 : Most amputations performed are for ischemic disease, primarily in elderly persons with diabetes mellitus. These patients often experience peripheral neuropathy that progresses to trophic ulcers and subsequent gangrene and osteomyelitis.
• Trauma: Severe open (IIIc) fractures with popliteal artery and posterior tibial nerve injuries can be treated with current techniques; however, treatment is at a high cost, and multiple surgeries are required. The result is often a leg that is painful, nonfunctional, and less efficient than a prosthesis.
• Tumors: Amputation is performed less frequently with the advent of advanced limb-salvage techniques.
• Infections: Treatment of sepsis with vasoconstrictor agents may at times lead to vessel occlusion and subsequent extremity necrosis, necessitating amputation. At other times, eradication of infection from many difficult sources necessitates removal of the affected digit or limbs.
• Congenital limb deficiency: Amputations for congenital limb deficiencies are performed primarily in the pediatric population because of failure of partial or complete formation of a portion of the limb. Congenital extremity deficiencies have been classified as longitudinal, transverse, or intercalary. Radial or tibial deficiencies are referred to as preaxial, and ulnar and fibular deficiencies are referred to as postaxial.

Pathophysiology

Amputation of the lower extremity is often the treatment of choice for an unreconstructable or a functionally unsatisfactory limb. Amputation must be performed with great care and be considered a reconstructive procedure, similar to total hip arthroplasty (internal amputation of the hip joint) or mastectomy (amputation of the breast), rather than an ablative procedure.

The higher the level of a lower-limb amputation, the greater the energy expenditure that is required for walking (see Image 1 to view the levels of amputation).³ As the level of the amputation moves proximally, the walking speed of the individual decreases, and the oxygen consumption increases.

For most people who have undergone transtibial amputations, the energy cost for walking is not much greater than that required for persons who have not undergone amputations. For those who have undergone transfemoral amputations, the energy required is 50-65% greater than that required for those who have not undergone amputations. Additionally, those with PVD who have undergone transfemoral amputations may have cardiopulmonary or systemic disease and require maximal energy for walking, making independence difficult to maintain.

Table. Energy Expenditure for Amputation

Open table in new window

Amputation wound healing is a concern because most amputations are performed for compromised circulation (eg, PVD, damaged soft-tissue envelope in trauma). The skin is a very important factor in the ambulatory ability and ultimate outcome for the person who has undergone an amputation. The soft-tissue envelope of the residual limb now becomes the proprioceptive end organ for the interface between the residual extremity and the prosthesis. For effective ambulation, this envelope should consist of a sufficient mass of mobile nonadherent muscle and full-thickness skin and subcutaneous tissue that can accommodate axial and shear stress within the prosthetic socket.

Split-thickness skin grafting is sometimes used to complete wound coverage or decrease tension on the wound closure, while maintaining the limb length. When placed over soft tissue with avoidance of bone scarring, these grafts can function quite well. However, most often these skin-grafted areas do not tolerate the axial and shear stresses within the prosthesis and may require removal at a later date, when the postoperative swelling has subsided. In the patient with vascular disease, preservation of limb length must be balanced with wound-healing ability and the potential for ambulation. A vascular surgery evaluation should be obtained to determine the feasibility of vascular reconstruction in the hopes of maintaining limb length.

For the patient to effectively transfer weight from the residual limb to the prosthesis, an intact soft-tissue envelope is required, as described above. Load transfer is accomplished through direct means, indirect means, or both. Direct weight transfer implies that the residual limb is capable of end weight bearing within a prosthesis. End weight bearing is easily accomplished through disarticulations at the ankle (Symes-level amputation) and knee levels. The proximal articulation of the joint is maintained, functions normally, and is broad enough to distribute the end-bearing forces.

Although joint amputations maintain length and muscle attachments, patients often have a difficult time with prosthetic fitting. The issues after knee disarticulations include that in which the more-distal center of knee rotation makes sitting in cars and closed areas difficult. The knee protrudes farther than the contralateral knee, and the lower leg is much shorter. For ankle disarticulations, patients report that the prostheses are too bulky.

Indirect weight transfer implies distributing load to a more proximal bony area and incorporating a total-contact interface with the soft tissues of the extremity. In the past, with transdiaphyseal amputations, an indirect weight transfer prosthesis has been used because of the small bone diameter, which is believed to be ineffective in applied load distribution. However, end weight bearing can be accomplished in osteomyoplastic reconstructions in conjunction with a total-contact prosthesis. This reconstruction provides a more durable, pain-free, active, and functional residual extremity. This operative procedure is described in Treatment, Surgical therapy.

Pain and the inactive residual extremity syndrome

Although the prosthetic industry has made significant advances over the past several decades, pain is still a problem for many patients who have undergone lower-extremity amputations. Prosthetists have been required to correct and relieve these painful and sensitive areas. Often, symptomatic or tolerable improvement is achieved; however, further surgical intervention can be necessary.

Pain in patients who have undergone lower-extremity amputations may originate from bone, muscle, nerve, or skin. These painful symptoms usually lead to significant disability, difficulty with daily activities, and decreased ability to wear the prosthesis.

A careful evaluation to determine the exact source of the pain is necessary. A common pitfall is to perform a simple revision surgery that just shortens the limb. This procedure may be unsuccessful if the reason for the pain has not been discovered and corrected.

Presentation

In patients with PVD, the diagnosis is usually known because these individuals have had extensive vascular studies and have most often undergone attempts at revascularization. With progressive small-vessel occlusion and neuropathy, toes become gangrenous and pressure points develop trophic ulcers, allowing bacteria to take hold and eventually invade the bone. Throughout treatment, costly measures are undertaken in attempts to salvage a marginally viable extremity, with the patient losing valuable productive time. The patient has often undergone multiple foot amputations and multiple debridements and is often wheelchair-bound for pain relief or for relief of pressure on the extremity. Additionally, the patient often has an ascending cellulitis due to venostasis or constant pain due to ischemic disease.

For trauma patients, the amputation may be the result of direct limb transection or a severe open fracture with an associated unreconstructable neurovascular injury. The limb is so severely injured that reconstruction is less functional than an amputation. The other end of the spectrum includes an unsuccessful prolonged limb salvage attempt that leaves the patient with a painful nonfunctional limb. The salvaged limb often requires a protracted course of treatment that takes a psychologic toll on the patient and absorbs significant emotional energy. The resulting limb may be less functional than a prosthesis would have been.

Osteomyelitis may be the result of systemic disease or of open fractures. Cultures or biopsy can often be used to identify the infecting organism. Gas gangrene is a very serious infection due to the Clostridium species, often resulting in amputation. Clostridial myonecrosis infections develop rapidly, and patients present with symptoms of pain, sepsis, and delirium. Examination on palpation often reveals a brownish discharge and crepitation within the soft tissues.

Streptococcal myonecrosis infections develop more slowly than clostridial infections. Persons with diabetes mellitus often develop polymicrobial infections that involve anaerobic gas-forming gram-negative organisms.

Malignancies often manifest with pain. The patient is often referred for amputation following a workup for a tumor, after limb salvage is excluded as an option.

Congenital limb deficiencies and malformations are evident and are present since birth. With growth, functional difficulties and limitations develop that limit the patient's mobility.

Indications

Amputation is the treatment of choice for diseased limbs and devastating lower extremity injuries for which attempts at salvage and reconstruction may be lengthy, emotionally and financially costly, and have a less-than-satisfactory result. Indications for limb removal include PVD, trauma, tumor, infection, and congenital anomalies.

The leading indication for limb amputation in the United States is PVD. Persons with diabetes mellitus account for 50% of the population with PVD. An estimated 65,000 lower extremity amputations are performed for this group each year. Limb removal for PVD is performed for uncontrollable soft-tissue or bone infection, nonreconstructable disease with persistent tissue loss, or unrelenting rest pain due to muscle ischemia.

Although safer equipment exists and improvements in limb salvage surgery have been made, traumatic limb loss continues to occur because of industrial and motor vehicle accidents. These accidents involve high-grade open fractures with associated nerve injury, soft tissue loss, and ischemia and unreconstructable neurovascular injury. In this setting, limb salvage may initially be successful, only to end in an infected painful extremity that affects the patient's activities of daily living and work. Attempts at limb salvage are often made with less-than-favorable results, leaving the patient with an extremity that is less functional than a prosthesis would be and resulting in workdays lost and expense in treatment.

The goal in treating malignant bone tumors is to remove the lesion with the lowest risk of recurrence. Limb salvage surgery has replaced amputation as the primary treatment for bone tumors. To recommend limb salvage, the risk of local recurrence must be equal to that of amputation, and the salvaged limb must be functional.

Congenital absence and limb malformations account for a small percentage of amputations. These situations are evaluated on an individual basis because these limbs are often functional and amenable to orthotic management or limb reconstruction. When considering amputation, a higher and more functional level than the patient's current level should be obtainable.

Whatever the indication for amputation, the goal remains length preservation and surgical reconstruction that maintains the most functional limb possible.

Relevant Anatomy

Knowledge of the regional cross-sectional anatomy of the lower limb is necessary to ligate the vessels and to identify the major nerves for sharp resection.

Contraindications

The decision to perform an amputation often comes after all other options have been exhausted. It is a final decision that cannot be reversed once initiated. The only contraindication to amputation is poor health that impairs the patient's ability to tolerate anesthesia and surgery. However, the diseased limb is often at the center of the patient's illness, leading to a compromised medical status. The removal of the diseased limb is necessary to eliminate systemic toxins and save the patient's life.

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