Accidental section of the ulnar nerve in the wrist during arthroscopy.

Arthroscopy of the wrist is a frequently performed procedure. Its role in diagnosis and treatment is significant. The complications of arthroscopy are well known and are described in the literature. We describe a case of accidental section of the ulnar nerve during repair of the triangular fibrocartilage complex during arthroscopy. The nerve section was caused by the trocar used for drainage in the 6U portal. We propose to establish the injury mechanism and describe a safe procedure for this examination.