Can the First Web Space Angle Be Predictive of Carpal Tunnel Syndrome?

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy in the upper limb. Although more objective methods for assessment have been reported in literature, there is a lack of evidence concerning the best methods for assessment of CTS. This study aimed to investigate whether there was a difference in the first web space in patients with different severities of CTS in relation to healthy controls as easy screen method.

This prospective controlled trial was conducted on 126 patients at the Physical Medicine and Rehabilitation Clinic, Ankara Diskapi Yildirim Beyazit Education and Research Hospital, University of Health Science, Ankara, Turkey, from January 2016 to January 2018. Hand grip and pinch strength of patients were determined. Also, first web angle were measured by goniometer. Patients were divided into 3 CTS groups as electrophysiologically: "mild: group 1", "moderate: group 2" and "severe: group 3". Patient and healthy groups were compared in terms of the evaluation parameters. Comparisons were also made between these groups.

There was significant reduction in hand strengths and first web angle in patient groups compared to healthy groups (P<0.05). Moreover, the first web angle was significantly different between the CTS groups (P= 0.001). The cut-off value for CTS was <38.5°.

The possibility of CTS can be evaluated by measuring the first web space angle with a simple goniometer as a easy and in-expensive method in outpatient clinics.