To review the randomized controlled trials (RCTs) and assess the comparative effectiveness of ultrasound-guided versus landmark-guided local corticosteroid injections in patients with carpal tunnel syndrome (CTS).

RCTs from Cochrane Central Register of Controlled Trials, MEDLINE (PubMed), EMBASE (Ovid), and Web of Science (from inception to 1 February 2017) were included. Two authors independently screened abstracts and full texts. The Outcomes of interest were symptom severity scale (SSS) and functional status scale (FSS) scores of Boston Carpal Tunnel Questionnaire as well as four electro-diagnostic parameters including compound muscle action potential, sensory nerve action potential, distal motor latency, and distal sensory latency.

Overall, 569 abstracts were retrieved and checked for eligibility and finally 3 RCTs were included (181 injected hands). Pooled analysis showed that ultrasound-guided injection was more effective in SSS improvement (mean difference [MD]=−0.46, 95% confidence interval [CI]=−0.59 to −0.32, P<0.00001); whereas, no significant difference was observed between the two methods in terms of FSS (MD= −0.25, 95% CI=−0.56 to 0.05, P=0.10). There were also no statistically significant differences in improvements of CMAP (MD=1.54, 95% CI=0.01 to 3.07, P=0.05), SNAP (MD=−0.02, 95% CI=−6.27 to 6.23, P=1.00), DML (MD=0.05, 95% CI=−0.30 to 0.39, P=0.80) or DSL (MD=0.00, 95% CI=−0.65 to 0.65, P=1.00).

Ultrasound-guided injection was more effective than landmark-guided injection in symptom severity improvement in patients with CTS; however, no significant differences were observed in functional status or electro-diagnostic improvements between the two methods.