Hip disarticulation is the surgical removal of the entire lower limb at the hip level. A traditional hip disarticulation is done by separating the ball from the socket of the hip joint, while a modified version retains a small portion of the proximal (upper) femur to improve the contours of the hip disarticulation for sitting. A hip disarticulation results most often from trauma, tumors and severe infections, such as necrotizing fasciitis. Less often, it results from vascular disease and complications of diabetes. A hip disarticulation prosthesis consists of three artificial joints, the hip, knee and ankle.