Anatomic and clinical study of a new surgical procedure with volar single-portal approach for minimally invasive treatment of carpal tunnel syndrome

Abstract

Objective To investigate the anatomical basis and clinical effects of a new surgical procedure with volar single-portal approach for minimally invasive treatment of carpal tunnel syndrome. Methods On 8 fresh adult upper limb specimens (16 sides), anatomical observation and measurement of carpal tunnel and palm structures were performed to determine the entry point, guide line and operative level of a new surgical procedure with volar single-portal approach for minimally invasive treatment of carpal tunnel syndrome. According to the anatomical findings, the new operation was performed on 68 patients with moderate to severe carpal tunnel syndrome. Postoperative recovery of the patients was followed up and compared with that of 75 patients who received conventional open carpal tunnel release at the corresponding period. Results According to the results of anatomical study, the best entry point of the surgical procedure was determined as following. A line parallel and ulnar to the metacarpophalangeal joint was drawn when the thumb was at maximum radial abduction. Another line was drawn along the long axis between the index and middle fingers. A 1-cm long vertical incision was made at 45° and 1-cm ulnar to the intersection of these two lines. The surgical projection line was the line connecting the surgical incision and the intersection point between palmaris longus tendon and distal wrist crease. The dissection plane was the space between the superficial palmar fascia and the palmar aponeurosis. The 68 minimally invasive surgery treated cases were follow-up for 6 to 12 months, the average follow-up being 9.5 months. Based on the carpal tunnel syndrome postoperative functional assessment criteria proposed by Gu, the results were satisfactory. Postoperative pain symptoms, sensory examination, muscle atrophy, thumb opposition, pinching and grip strength were all significantly improved. There was very little postoperative scar pain. Compared with the conventional surgery the minimally invasive procedure has obvious advantages. Conclusion Volar single-portal approach for minimally invasive treatment of carpal tunnel syndrome has sound anatomical basis. It can effectively reach and divide the transverse carpal ligament, decompress the median nerve. Therefore it is an effective minimally invasive approach in the treatment of carpal tunnel syndrome. Key words: Carpal tunnel syndrome; Surgical procedures, minimally invasive; Anatomy; Clinical study