A biosynthetic thumb prosthesis.

Abstract

In cases of severe damage to the extremities, the function and structure of compromised tissues must be replaced. If biological reconstruction using autologous tissue is not feasible, amputation and replacement with a synthetic prosthesis is often the next best option. Synthetic prostheses are limited, especially in their ability to restore skin sensation. Here we show a biosynthetic prosthesis that combines the versatility of titanium with the rich sensory capabilities of biological skin. The prosthesis recreates opposition pinch by linking motion of the prosthetic joint to that of the residual biological joint, and is enclosed in neurotized skin from the patient's own body. We validated the biosynthetic thumb's mechanical function on the benchtop and in a cadaver, and showed viability of the skin interface in an animal model. These results provide a framework for functional reconstruction of amputated digits using a combination of synthetic materials and biological tissues.