Articulated cadaveric bones as a structural endoskeleton in an ankle-foot prosthesis: a preliminary report.

This report describes the construction and evaluation of an ankle-foot prosthesis using human cadaveric bones as the endoskeleton inside a fiber-reinforced vulcanized rubber shell. Cadaveric bones and exhumed skeletal bones were used. Three designs were fabricated, subjected to radiographic evaluation, and underwent 4-week field trials of normal daily use by a unilateral below-knee amputee. The rubber shell retained the position of the bones, permitted movements at the joints in various stages of the stance phase, and restored the bones to their neutral position when the foot was unloaded. The cadaveric prosthesis provided for plantar flexion of the foot when the heel was loaded and for locking of the joints to restrain excessive movement when the foot came to rest. While fresh cadaveric bones withstood all the stresses of active walking, exhumed macerated bones fractured and fragmented with use.