Comparison of Ultrasound-Guided Versus Landmark-Based Corticosteroid Injection for Carpal Tunnel Syndrome: A Prospective Randomized Trial

Purpose: Although a local corticosteroid injection for carpal tunnel syndrome (CTS) is frequently performed by palpation using anatomical landmarks, ultrasound (US) allows physicians to visualize and confirm placement of the injectate close to the median nerve, possibly improving the efficacy of the injection. The aim of this study was to compare the effectiveness and complications of US-guided steroid injections with landmark-based injections for CTS. Methods: A total of 102 patients with CTS were randomized into 2 groups: landmark-based injection and US-guided injection. The response to treatment, including grip strength and the Boston Carpal Tunnel Questionnaires (BCTQ) was assessed at baseline and at 4, 12, and 24 weeks after the injection. Results: The BCTQ symptom and function scores were similar in the 2 groups throughout the 24-week follow-up period, with the exception of significantly lower (better) symptom scores at 4-week follow-up in the US-guided injection group. The grip strength was similar in the 2 groups throughout the 24-week follow-up period. After 24 weeks, 12 patients (24%) in the landmark-based injection group and 9 patients (18%) in the US-guided injection group had undergone carpal tunnel surgery. Symptoms of median nerve irritation were more likely to occur in patients with landmark-based injections (14%) than in those with US-guided injection (2%). Conclusions: A US-guided steroid injection for CTS produces pain and functional results similar to those of landmark-based injection. Type of study/level of evidence: Therapeutic I.