Evaluation of the Effectiveness and Safety of Ultrasound-Guided Percutaneous Carpal Tunnel Release: A Cadaveric Study.

OBJECTIVE: The looped thread carpal tunnel release (TCTR) procedure is a minimally invasive percutaneous technique performed under ultrasound (US) to transect the transverse carpal ligament in patients with carpal tunnel syndrome. Study objectives were to evaluate the accuracy of identifying key US landmarks, safety, effectiveness, and technical difficulty of TCTR.

DESIGN: Fourteen lightly embalmed cadaveric distal forearm-hand specimens were subject to US identification of key landmarks, TCTR procedure, and post-TCTR dissection. Outcome measures of interest were (1) correspondence between key landmarks (median nerve and 4 bony pillars of transverse carpal ligament) identified on US and anatomical structures exposed by dissection, (2) percentage of the transverse carpal ligament transected and location of the transection, (3) frequency of damage to adjacent structures, (4) time to complete procedure, and (5) operator assessment of technical difficulty of each TCTR procedure (0 = extremely easy, 10 = extremely difficult).

RESULTS: (1) Skin markings delineating the position of US-visualized landmarks corresponded almost perfectly to anatomical dissection. (2) Nine (64.2%) of 14 specimens had complete division of the transverse carpal ligament. In the remaining 5 specimens, an average of 68.8% of the ligament was transected. (3) No adjacent structures were damaged. (4) Time to complete the procedure was on average 9.9 ± 4.6 minutes. (5) Average procedural difficulty was 4.3/10.

CONCLUSIONS: Thread carpal tunnel release is potentially a safe, quick, and effective procedure to transect the transverse carpal ligament. Future clinical investigation is recommended.