Ulnar nerve compression secondary to migration of pyrocarbon implant following right wrist arthroplasty

A 50-year-old, right-hand dominant woman presented with a seven-month history of stiffness, pain and swelling on the ulnar side of her right wrist. She had undergone right wrist arthroplasty with a Pyrocarbon Amandys implant seven months previously for post-traumatic degenerative arthritis. She had an uneventful initial recovery until developing carpal tunnel syndrome, for which she underwent carpal tunnel release 5 months after her arthroplasty. Examination revealed a painful and limited range of movement in the affected wrist, with weakness of the first dorsal interosseous muscle and altered sensation in the ring finger. A hard swelling was visible and palpable on the palmar-ulnar aspect of the wrist. X-rays showed that the swelling was due to the dislocated Amandys implant (which was thought to be causing compression neuropathy of the ulnar nerve). The patient underwent removal of the pyrocarbon implant (through a palmar approach) and total wrist fusion one month later, following which the wrist successfully united and all symptoms of ulnar nerve compression resolved. Although some studies have reported migration of pyrocarbon implant following total wrist arthroplasty, to our knowledge, this is the first reported case of ulnar compression neuropathy from a migrated pyrocarbon wrist implant.