Does carpal canal stenosis predict outcome in women with carpal tunnel syndrome?

Objective - We investigated the role of carpal canal stenosis as a predictor of outcome in patients who underwent surgical treatment for carpal tunnel syndrome (CTS). Methods - We performed magnetic resonance imaging (MRI) of the wrist in 31 female patients with clinically and neurophysiologically confirmed CTS. With a computerized analyser we quantitatively calculated the focal narrowest point of the tunnel. Patient's assessment of CTS-related symptoms were obtained by using a visual analogue scale before, and 6 months after treatment. Results - Seventeen (56%) patients improved in all symptoms after treatment. The focal narrowest point of the tunnel was identified at its distal third in all patients, at 8 mm from the outlet. The median area of the narrowest point in those who improved clinically (n = 17) was 238.9 mm(2) compared with 269.8 mm(2) in others (n = 14), P = 0.046. Conclusion - Identification of carpal canal stenosis may be important in selecting candidates for treatment in symptomatic CTS.