The different forms of surgeries that fall under the heading of "leg amputations" range from minor, such as those involving a portion of the foot, to major, in which a large portion of the leg or the whole leg is removed. Surgeons can amputate a portion of the foot, above the knee or below the knee, at the ankle, or at the hip. It is preferred to amputate below the knee, if possible, because it is easier to fit a prosthesis afterward. The type of leg amputation required depends on factors such as overall patient health, blood flow, gangrene, and infection.
The main reasons for a leg amputation involve blocked arteries resulting from atherosclerosis, while up to 40 percent of amputations involve patients with diabetes. Once gangrene develops, it can spread rapidly and kill a patient if the affected limb is not amputated. If bypass surgery is not an option, a surgeon must decide how much of the leg to remove. Even without gangrene, serious infections can be life-threatening, and pain may be a serious problem in the patient’s life. The presence of tumors and, less commonly, serious accidents, also can result in leg amputations.
Minor leg amputations can be as simple as removing a toe, but another option is a ray amputation, in which a toe and a portion of the metatarsal bone is removed. The remaining parts of the foot are sewn back together and the patient can walk on it once the wound heals. If more than one toe is affected by gangrene, a forefoot amputation might be performed. Amputation of the whole foot is possible, but it is important that the posterior tibial artery is healthy. Most patients don't meet the criteria for this surgery, and it is rarely recommended for people with diabetes.
The major classes of leg amputations also include a below-knee, or b-k amputation, and an above-knee, or a-k amputation. If leg amputations occur below the knee, surgeons can either bring calf muscle and skin around to the shin bone to wrap the resulting wound, or they can bring just the muscles forward and use a "skew flap" to position the skin. Both techniques provide the same advantage after a leg amputation and produce a stump suitable for fitting a prosthesis.
A hip disarticulation is the removal of the entire leg. Surgeons are usually able to preserve part of the upper leg bone, called the femur, so a prosthetic can be used. When preparing for a leg amputation, vascular surgeons must determine the blood flow and overal health of the patient. The goal is to perform leg amputations that will give patients the best chances of walking again and having a relatively decent quality of life.
