Bilateral pisiform-hamate coalition causing carpal tunnel syndrome and tendon attrition. A case report.

Congenital coalition of pisiform and hamate is rare and had been considered asymptomatic in the first reports. The authors report a case of bilateral pisiform-hamate coalition in a young patient, causing symptoms of median nerve compression in the carpal tunnel and attritional changes on digital flexor tendons. This type of coalition had not previously been related to such symptoms. Additionally, the morphology of the coalition on the right side is unique among published cases. Surgical treatment with bilateral excision of the coalition resulted in the resolution of symptoms.