Effect of ultrasound-guided versus landmark-guided local corticosteroid injection for carpal tunnel syndrome: a systematic review and meta-analysis

Background Carpal tunnel syndrome (CTS), the commonest neuropathy of the upper limb, can be managed with different therapeutic approaches. Local corticosteroid injection has been adopted widely in clinical practice, as it showed great efficacy in treating CTS. However, the best injection technique continues to be a subject of controversy. The aim of this systematic review and meta-analysis was to evaluate the efficacy of ultrasound-guided (US-guided) versus landmark-guided (LM-guided) corticosteroid injection on the clinical and electrophysiological outcomes in patients with CTS. Methods We performed a systematic literature search in Medline, Embase, and CENTRAL, from which we included randomized controlled trials (RCTs) that compared US-guided and LM-based corticosteroid injection in treating individuals with CTS. We evaluated the following outcomes: Boston carpal tunnel questionnaire functional status scale (BCTQ-FSS) and symptom severity scale (BCTQ-SSS), and adverse event rate. The standardized mean difference (SMD) was used to represent continuous outcomes, while the risk ratio (RR) was used to represent dichotomous outcome. Results A total of 8 RCTs that enrolled 500 wrists were deemed eligible. US-guided injection showed a significantly better BCTQ-FSS (SMD = –0.22, 95% CI –0.39 to –0.04), BCTQ-SSS (SMD = –0.77, 95% CI –1.22 to –0.31), and adverse event rate (RR = 0.32, 95% CI 0.21 to 0.49) compared to LM-based injection. Conclusion This meta-analysis showed the superiority of US-guided corticosteroid injection over LM-guided corticosteroid injection in enhancing functional status, improving symptom severity, and reducing the adverse event rate in individuals with CTS.