Long-term analysis of patients having surgical treatment for carpal tunnel syndrome.

This retrospective study of 100 patients who had surgical treatment for their carpal tunnel syndrome was performed to determine what factors were associated with long-term success or failure. One hundred thirty hands were treated surgically with an average follow-up of 4 years (range, 2 to 6 years). All patients were given a course of conservative treatment that included steroid injection(s) and splinting until the patients were refractory to such therapy. Over 250 injections were given (117 wrists), with the average benefit time of 27 weeks (range 0 to 330). Most patients received two to three injections (maximum of nine). Variables associated with a failure to have long-term benefit after operation included weakness or atrophy of the abductor pollicis brevis muscle, presence of a predisposing condition, and failure to benefit from the initial steroid injection. Conversely, all 51 hands that had relief from median nerve paresthesia for more than 6 months by conservative therapy alone received long-term relief after surgery. Steroids were least effective in hands that had muscle involvement. Fifteen of the 40 hands with muscle involvement regained their muscle mass by the time of the final examination.