The role of ultrasonography in the assessment of carpal tunnel syndrome.

EMBASE and MEDLINE databases were searched by using PUBMED and OVID software. The search terms ‘‘carpal tunnel syndrome’’ (CTS), and ‘‘carpal tunnel syndrome and ultrasound’’ were used to identify 1,537 citations. Prospective clinical trials with defined control groups and clinical criteria for gold reference standard were selected for inclusion in this meta-analysis. The study group included at least 50 wrists, so to provide adequate power to the study, and the study compared results with a healthy control group. Blinding of the sonographer involved in measurements was also integrated in the study design. The study by Nakamichi and Tachibana [1] involved large patient and control group numbers (414 symptomatic wrists vs 408 control wrists). Nerve conduction studies (NCS) were performed in both groups and were compared with sonography. The median nerve cross-sectional area (CSA) was measured by using the tracing method at 3 anatomical levels: the distal edge of the flexor retinaculum (level 1), the hook of