Abstract
A patient with silastic radiocarpal and ulnar head replacement arthroplasty presented six years after the operation with symptoms of ulnar neuropathy. Bone resorption of the distal ulna resulted in volar subluxation of the ulnar head implant which compressed the ulnar nerve at its entrance into Guyon's canal. Removal of the implant and decompression of the nerve resulted in recovery of ulnar nerve funcions. Compression neuropathy of the ulnar nerve should be considered a potential complication of the use of silastic ulnar head replacements.