Does median nerve translate pre- and postoperatively in carpal tunnel syndrome?

Objectives: This study aims to evaluate the distance between the median nerve and the hook of the hamate pre- and postoperatively in patients with carpal tunnel syndrome and to investigate the efficiency of magnetic resonance imaging in diagnosis and postoperative follow-up.

Patients and methods: Median nerve decompression was performed by releasing the carpal tunnel in 15 patients (4 males, 11 females; mean age 51 years; range, 41 to 66 years) with carpal tunnel syndrome. The shortest distance between the median nerve and the hook of the hamate was measured with magnetic resonance imaging preoperatively and at three months after the operation and radial and ulnar translations were assessed. Findings were compared to those of a control group of 15 subjects (5 males, 10 females; mean age 52.2 years; range, 40 to 65 years).

Results: Median nerve shifted ulnarwards in patients with carpal tunnel syndrome. An intragroup evaluation of five patients with thenar atrophy revealed that as disease severity increased, the degree of the nerve's medial translation increased. Compared to preoperation, the median nerve significantly shifted to the radial side after decompression.

Conclusion: In carpal tunnel syndrome patients, we observed significant ulnar translation of the median nerve and lateral translation after releasing the carpal tunnel. Magnetic resonance imaging may be used to establish a diagnosis and to assess operation success in advanced carpal tunnel syndrome patients who may recover slowly postoperatively.