Abstract: A trapezium-metacarpal thumb joint prosthesis having a metacarpal component for insertion into a metacarpal bone of a human thumb and a trapezium component for insertion into a trapezium bone of a human thumb. The metacarpal component has a forward end of generally truncated hemispherical shape with a convex surface and a rear end having a base and a stem. The trapezium component has a forward end of a generally cylindrical shape with a concave surface with a radially built up shoulder and a rear end having a base and a stem. The concave surface is adapted for non-captive rotational abutment with the convex surface. Also, a related method for implantation of the prosthesis into the metacarpal and trapezium bones of a human thumb, wherein the two components are respectively inserted into a pre-cut void in each of the respective bones from a direction above the radial side of the thumb substantially transverse to the longitudinal axis of each respective bone of the thumb.

Abstract: A nonconstrained, total great toe joint implant for the metatarsophalangeal joint made of a first component with a convex, partially spherical surface ending in a rear surface from which a longitudinally asymmetric implantation stem projects and having a flange on the dorsal side of the implant which extends the convex surface past the rear surface. The rear surface is inclined 10.degree. relative to a normal plane which intersects this surface. The metatarsal bone is resected accordingly. The phalangeal implant component is made of a base with a stem for placement in a bone cavity, projecting from a rear side thereof and having a low-friction, concavely curved insert affixed to the base which slidably engages and cooperates with the convex surface of the metatarsal implant component.