Endoscopic revision of carpal tunnel release.

Background: Open revision has been the standard approach for treatment of recurrent carpal tunnel syndrome. The authors hypothesized that endoscopic revision would yield results comparable to those with open revision.

Methods: Forty-one patients with unilateral recurrence were analyzed prospectively before and after endoscopic revision for a period of 1 year. All had clinical signs or symptoms, a positive response to a steroid injection, and electrodiagnostic findings consistent with carpal tunnel syndrome after primary open release and had failed to improve after an average of 16 months. Follow-up evaluations were performed with validated outcome instruments and quantitative measurements of strength and sensation.

Results: Thirty-seven of the 41 patients reported improvement after the endoscopic revision. Significant improvement was seen at 3 and 12 months after the procedure in the Carpal Tunnel Syndrome Symptom Severity Score, the Carpal Tunnel Syndrome Functional Status Score, the University of Washington satisfaction score, pinch strength and sensation, and a decrease in scar sensitivity. An improvement in grip strength was measured after 12 months. The satisfaction score was found to be significantly correlated to the Symptom Severity Score and the Functional Status Score.

Conclusions: Endoscopic release of recurrent carpal tunnel syndrome may be performed safely using standard technique with good results. The advantage of the procedure is the ability to approach the tunnel while avoiding the scarring related to the previous open approach. This technique is not adequate for cases after several open revisions, suspected nerve injury, or extension of the previous open approach proximal to the wrist crease.