Modified Camitz Opponensplasty Using Transverse Carpal Ligament Loop Pulley in Patients with Advanced Carpal Tunnel Syndrome

Abstract

Sir:FigureThumb opposition is a key factor in providing motion and strength for both prehension and grasp. In advanced carpal tunnel syndrome, severe thenar muscle atrophy precludes effective opposition. The recovery of thenar muscle atrophy is unpredictable even after carpal tunnel release.1,2 Camitz described palmaris longus transfer as augmenting thumb opposition in carpal tunnel syndrome with severe thenar muscle atrophy.3 However, his transfer restored palmar abduction rather than true opposition because of the inefficient line of pulling. In this study, we introduce a modification of the Camitz procedure using the ulnar-based transverse carpal ligament loop pulley and report the results of our early series. Under general anesthesia or an axillary block, a curved palmar incision was made from the distal palmar crease to 1 inch proximal to the distal wrist crease. The palmaris longus tendon was elevated in continuity with the third ray pretendinous band and was reflected proximally. By dividing the proximal third of the transverse carpal ligament near the radial attachment and ulnarward extension, a transverse carpal ligament flap was elevated (Fig. 1). The transverse carpal ligament flap was reflected ulnarward and sutured to itself near its pisiform attachment site with two or three nonabsorbable polypropylene stitches, which resulted in the ulnar-based transverse carpal ligament loop pulley. The remaining distal portion of the transverse carpal ligament was released to decompress the median nerve. After passing through the loop pulley and subcutaneous tunnel, the previously elevated palmaris longus with its fascial extension was secured to the abductor pollicis brevis insertion with appropriate tension (Fig. 1). Postoperatively, a thumb spica plaster splint immobilization was kept for 4 weeks. Gentle active range-of-motion exercise of the thumb and wrist was permitted from the fifth week after the operation.Fig. 1: (Above) After elevation and proximal reflection of palmaris longus-pretendinous band (arrowheads), the ulnar-based proximal one-third transverse carpal ligament flap (arrow) was created. (Below) The palmaris longus tendon with its fascial extension was passed through the transverse carpal ligament loop pulley (arrow) and was secured to the abductor pollicis brevis insertion and dorsoradial expansion hood of the first metacarpophalangeal joint (arrowhead).From March of 2006, nine wrists in eight patients with advanced carpal tunnel syndrome accompanied by severe thenar muscle atrophy underwent open carpal tunnel release and opponensplasty using our modified method and were followed for more than 1 year. At an average 24-month (range, 14 to 46 months) follow-up, the average maximal palmar abduction4 was 90.1 percent and the average Kapandji tip opposition score was 92.4 percent that of the opposite sides. The mean grip strength and key pinch strength were 92.1 percent and 93.9 percent, respectively. The functional outcome based on the Boston questionnaire revealed that the mean symptom score was 1.24 and the mean sign score was 1.22. The subjective gradings of the overall functional outcome by patients were four “complete cure” and five “much better” (Table 1). No postoperative complications were noted related to transverse carpal ligament loop pulley.Table 1: Summary of Cases with a Modified Camitz OpponensplastyCompared with other reports1,2,5 of simple carpal tunnel release or palmaris longus transfers in advanced carpal tunnel syndrome, the overall functional outcome of our series was quite encouraging. The transfer directed toward the pisiform with the combination of a stable pulley can provide the efficient line of pull and power for opposition (Fig. 2). Even though the number of cases is small, our simple modification of the original Camitz procedure using an ulnar-based transverse carpal ligament loop pulley revealed improved opposition, grip, and pinch powers; functional scores; and patient satisfaction, without major complications.Fig. 2: (Above) A 64-year-old woman presented with severe thenar muscle atrophy and an inability to perform thumb abduction and opposition of the right hand (case 7). (Below) At 20-month follow-up, she had uncollapsed tip-to-tip opposition with recovered abduction and pronation of the thumb (arrow).Soo-Whan Kang, M.D. Yang-Guk Chung, M.D. Joo-Yup Lee, M.D. Woo-Lam Jo, M.D. Department of Orthopedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea DISCLOSURE The authors have no financial relationships to disclose. ACKNOWLEDGMENT This study was supported by Seoul St. Mary's Clinical Medicine Research Program year of 2011 through The Catholic University of Korea.