Ulnar bursa distention following volar subluxation of the distal radioulnar joint after distal radial fracture: a rare cause of carpal tunnel syndrome.

This report describes an eighty-four-year-old woman with persistent carpal tunnel syndrome attributable to an ulnar bursa distention associated with the subluxation of the distal radioulnar joint after distal radial fracture. During surgery, when the forearm was placed in supination, the ulna head with a sharp osteophyte was found to be displaced into the carpal tunnel through a defect of the ruptured capsule of the wrist joint. This volar subluxation of the ulnar head had caused distention of the ulnar bursa, causing compression of the median nerve, which resulted in carpal tunnel syndrome. In addition to reduce displaced fractured segment to obtain anatomic articular surface, original radial length and tilt, the anatomic restoration of the distal radioulnar joint is essential to maintain better long-term function after fracture of the distal radius.