Abstract: A metacarpophalangeal prosthesis includes a metacarpal component having a head portion and a phalangeal component having a socket portion. The head portion rotatably engages the socket portion member. The head portion is either circular or spherical, and the socket portion member is formed so as to cooperate rotatably with the head portion. In its preferred embodiment, a pair of shoulders are formed on the sides of a circular disk-like head portion and a pair of spaced apart surfaces are formed on the socket portion which contact the shoulders of the head portion when the phalangeal component is at maximum flexion. This contact constrains radial and ulnar deviation between maximum flexion and maximum extension such that at maximum flexion radial and ulnar deviation are constrained virtually altogether, while at the neutral position and at maximum extension, limited range of motion and limited radial and ulnar deviation is permitted.

Abstract: An implant comprising a specially adapted bone screw having a threaded shank portion and a sleeve which mates with and operates in cooperation with the threaded shank portion is provided. Also provided is a driver specially adapted for inserting and removing the implant of the invention. A method of compressing a fracture in a bone is also provided. The implant generates bone compression by itself and can be used either alone or with plates and washers. It is easily inserted into a fracture and also is easily removed from the fracture. The driver which is specially adapted to be used in combination with the implant of the invention aids in the ease of insertion and removal of the implant.