Effectiveness of wrist tube inside and outside releasing for treating median nerve double entrapment at wrist

Abstract

To investigate the effectiveness of wrist tube inside and outside releasing for treating median nerve double entrapment at wrist. Thirty-one patients of median nerve double entrapment at wrist were treated between April 2011 and May 2014. There were 8 males and 23 females with an age of 33-69 years (mean, 56.4 years). In palm lateral three and a half finger, the two-point discrimination was 7-14 mm (mean, 9.5 mm), in which 24 cases were 4-10 mm and 7 cases were more than 10 mm. Carpal tunnel median nerve Tinel sign was positive; there was weak and acid swollen felling when press big thenar muscle on median nerve return branch palm surface projection points. Electromyography examination showed that median nerve endings movement incubation period was 4.5-10 ms in 22 cases, more than 10 ms in 9 cases; fibrillation potentials and positive phase voltage happened in 6 cases; the median nerve sensory conduction velocity of all patients was slow, and the motor conduction velocity also slowed down; the motor amplitude was 5-10 mV in 19 cases, less than 5 mV in 12 cases. The disease duration was 3-8 months (mean, 5.5 months). Surgical exploration of wrist median nerve in carpal tunnel and median nerve return branch outside carpal tunnel were performed in patients, especially completely released the variety entrapment factors such as thickening bow at starting point of short hallux flexor tendon, fiber bundles at ulnar side of short hallux flexor tendon, deep layer fiber of the palmar aponeurosis, and variant shallow head of short hallux flexor. All the wounds healed by first intention without wound scar pain. The patients were followed up 24-59 months (mean, 33 months). Night numbness and pain disappeared, and weak and acid swollen feeling in big thenar muscle on median nerve return branch points also disappeared. The sensation recovered to S 4 in 28 patients in palm lateral three and a half finger, the index and middle fingertip sensation recovered to S3+ in 3 cases. In the median nerve innervation area, the two points discrimination was 4-6 mm (mean, 4.8 mm). The thumb opposition function returned to normal in 29 cases and mild confinement in 2 cases. The grip strength of all the 31 cases recovered, and 1 of them increased significantly. In preoperative big thenar muscle atrophy cases, muscle strength recovered to S 5 in 4 cases, S 4 in 2 cases. At 2 years after operation, according to the functional assessment of carpal tunnel syndrome recommend by GU Yudong, the results were excellent in 29 cases and good in 2 cases, with an excellent and good rate of 100%. When treating the nerve double entrapment in wrist using wrist tube inside and outside releasing method, the variety entrapment factors of return branch of median nerve should be completely released, so the effectiveness can be improved.