US Patent 7976580 Semi-constrained 1

A first carpometacarpal joint implant. One embodiment of the invention includes proximal and distal components. The proximal component includes a fixation portion for attachment to one or more elements of a patient's distal carpal row, a ball-type joint portion cantilevered off the fixation portion, and a skid having a concave surface opposite the ball-type joint for engaging a patient's scaphoid bone. The distal component has a fixation portion for attachment to a patient's thumb metacarpal, and a socket-type joint portion that cooperates with the ball-type joint portion of the proximal component.