Disarticulation
In surgery , disarticulation is understood to mean the amputation of a limb in the joint (articulatio). All of the soft tissues surrounding a joint are severed; In contrast to ablation, the bone of the amputation stump remains uninjured. Frequent disarticulations can be found u. a. in the ankles according to Lisfranc or Chopart or in the knee or hip joint (see: hip disarticulation ). Hemipelvectomy , which means the resection of an entire half of the pelvis, is rare .
The advantage of a disarticulation, especially on the knee joint, is that a residual limb that can withstand extreme loads is retained. Since the stump is longer than with an amputation above the joint, more force is retained and the longer lever arm allows better control of the prosthesis. However, wound healing in disarticulation stumps in patients with arterial occlusive disease or diabetes , the main causes of amputations of the lower extremities, is often very problematic due to the lack of muscular residual limb coverage, which is why disarticulation, especially on the knee, is recommended for traumatic or oncological indications.
The higher the amputation, the more problematic the provision of a prosthesis , and depends primarily on the shape of the stump and the soft tissue covering. A cosmetic problem with knee joint disarticulation is that the thigh with the prosthesis is longer than the mutually healthy thigh, since the artificial knee joint has to be attached to the prosthesis beyond the normal length of the thigh. Special joints are available for this purpose, which require significantly less length than knee joints in transfemoral amputees, but there is a difference of 5 to 6 cm, which is particularly noticeable when sitting.
