There is a small group of patients with gangrene of vascular origin for whom conservation of the knee joint by means of a midleg amputation is possible despite the presence of extensive necrosis of the musculature below the knee. A necessary prerequisite to any such attempt at limb conservation is the presence of viable skin over the extent of the proposed stump. All nonviable muscle is excised in the course of the procedure leaving behind the skin, subcutaneous tissue, deep fasciae, and bones. Indications for the technique to be detailed are limited and the usefulness of such a stump depends on the following anatomicophysiological facts:
(1) The motor power for use of the knee joint comes from muscles situated in the thigh, and not below the knee.
(2) Weight bearing in a below-the-knee prosthesis is at the tibial plateau level and not at the distal portion of a midleg prosthesis.