Systematic Review
Ultrasonography is used to diagnose carpal tunnel syndrome (CTS) according to various criteria. This diagnostic meta-analysis aimed to evaluate the efficacy of ultrasonography for diagnosing CTS, focusing on the cross-sectional area (CSA) of the median nerve (MN) at the inlet of the carpal tunnel and regional variations in diagnostic thresholds between Asian and non-Asian populations./r/nA comprehensive literature search was conducted using PubMed, Embase, and the Cochrane Library. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Patient demographic data, diagnostic “gold standards”, CSA cutoff values, and diagnostic results were extracted. Meta-analysis was performed to determine the sensitivity, specificity, and optimal CSA cutoff values./r/nFor the 25 included studies, a combined sensitivity of 88% and specificity of 84% for CSA measurements at the carpal tunnel inlet were obtained. The Asian group had a sensitivity of 84% and specificity of 86%, while the non-Asian group had a sensitivity of 91% and specificity of 82%. The mean CSA in the Asian group was significantly lower than that in the non-Asian group (12.93 mm and 14.77 mm, respectively; p = 0.042). For the Asian group, the summary receiver operating characteristic curve had an area under the curve (AUC) of 0.92 with an optimal cutoff of 10.5 mm; for the non-Asian group, an AUC of 0.94 was obtained with a cutoff of 11.5 mm./r/nUltrasonography is a reliable diagnostic method for CTS, with distinct optimal cutoff values observed between Asian and non-Asian populations. Therefore, population-specific diagnostic criteria for CTS are recommended.