Carpal tunnel syndrome associated with Kienböck disease.

We retrospectively reviewed 12 patients (3 men and 9 women, with a mean age of 72 years) who were surgically treated for carpal tunnel syndrome associated with Kienböck disease. All patients except 1 were incidentally diagnosed with Kienböck disease and had little or no wrist pain. Radiographic tests revealed advanced Kienböck disease in all patients. Intraoperative findings indicated that the site of maximum compression on the median nerve was located at the level of the carpal tunnel inlet in 11 patients, and the volar dislocated fragment of the lunate was located proximally adjacent to the floor of the carpal tunnel inlet. This disorder is most prevalent in elderly women, and even advanced Kienböck disease can present without wrist pain. Our findings suggest that palmar protrusion of the lunate may be the primary cause of carpal tunnel syndrome associated with Kienböck disease.