Carpal tunnel syndrome secondary to an osteophyte of the trapezium

We report a 42-year-old man with a rare carpal tunnel syndrome (CTS) secondary to an osteophyte of the trapezium. The patient presented with a 3-year history of CTS, consisting of progressive pain and paresthesias in his right hand, positive Tinel and Phalen signs, and an electrodiagnostic study demonstrating median nerve compression at the wrist. The procedure was an open carpal tunnel release. Intraoperatively, a bony protuberance was found beneath the transverse carpal ligament (TCL), resulting in compression of the median nerve. The median nerve was decompressed and the patient's symptoms resolved postoperatively. Surgical pathology revealed bony fragments, and a postoperative CT scan was supportive of an osteophytic remnant protruding from the trapezium. Carpal bone osteophytes are rarely reported causes of CTS.