Amputation is the removal of a limb by trauma, medical illness, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for such problems. A special case is that of congenital amputation, a congenital disorder, where fetal limbs have been cut off by constrictive bands. In some countries, amputation of the hands, feet or other body parts is or was used as a form of punishment for people who committed crimes. Amputation has also been used as a tactic in war and acts of terrorism; it may also occur as a war injury. In some cultures and religions, minor amputations or mutilations are considered a ritual accomplishment.
In some rare cases when a person has become trapped in a deserted place, with no means of communication or hope of rescue, the victim has amputated his or her own limb. The most notable case of this is Aron Ralston, a hiker who amputated his own right forearm after it was pinned by a boulder in a hiking accident and he was unable to free himself for over five days.
Distal stabilisation of muscles is recommended. This allows effective muscle contraction which reduces atrophy, allows functional use of the stump and maintains soft tissue coverage of the remnant bone. The preferred stabilisation technique is myodesis where the muscle is attached to the bone or its periosteum. In joint disarticulation amputations tenodesis may be used where the muscle tendon is attached to the bone. Muscles should be attached under similar tension to normal physiological conditions.
The use of rigid removable dressings (RRD's) in trans-tibial (below knee) amputations, rather than soft bandaging has been shown to improve healing time, reduce edema, prevent knee flexion contractures and reduce complications, including further amputation, from external trauma such as falls onto the stump and should be considered standard practice.
Orthopedic surgeons often assess the severity of different injuries using the Mangled Extremity Severity Score. Given different clinical and situational factors, they can predict the likelihood of amputation. This is especially useful for emergency physicians to quickly evaluate patients and decide on consultations.
Methods in preventing amputation, limb-sparing techniques, depend on the problems that might cause amputations to be necessary. Chronic infections, often caused by diabetes or decubitus ulcers in bedridden patients, are common causes of infections that lead to gangrene, which would then necessitate amputation.
A large proportion of amputees (50–80%) experience the phenomenon of phantom limbs; they feel body parts that are no longer there. These limbs can itch, ache, burn, feel tense, dry or wet, locked in or trapped or they can feel as if they are moving. Some scientists believe it has to do with a kind of neural map that the brain has of the body, which sends information to the rest of the brain about limbs regardless of their existence. Phantom sensations and phantom pain may also occur after the removal of body parts other than the limbs, e.g. after amputation of the breast, extraction of a tooth (phantom tooth pain) or removal of an eye (phantom eye syndrome).
In many cases, the phantom limb aids in adaptation to a prosthesis, as it permits the person to experience proprioception of the prosthetic limb. To support improved resistance or usability, comfort or healing, some type of stump socks may be worn instead of or as part of wearing a prosthesis.
Nearly half of the individuals who have an amputation due to vascular disease will die within 5 years, usually secondary to the extensive co-morbidities rather than due to direct consequences of amputation. This is higher than the five year mortality rates for breast cancer, colon cancer, and prostate cancer. Of persons with diabetes who have a lower extremity amputation, up to 55% will require amputation of the second leg within two to three years.