Ultrasound- vs Landmark-Guided Steroid Injection for Carpal Tunnel Syndrome

CLINICAL QUESTION

Is steroid injection guided by ultrasonography (US) superior to landmark-guided injection for carpal tunnel syndrome?

EVIDENCE-BASED ANSWER

US-guided steroid injection should be considered for carpal tunnel syndrome because statistically significant benefits have been shown in symptom and functional improvement and a reduced rate of complications (number needed to treat [NNT] = 5) compared with landmark-guided injection. (Strength of Recommendation: A, meta-analyses.)

EVIDENCE SUMMARY

A 2023 Cochrane review of 14 randomized controlled trials (RCTs) and quasi-RCTs (nine with quantifiable data) examined effects of local, landmark-guided corticosteroid injection vs no treatment or placebo injection.¹ Studies included patients 18 years and older diagnosed with carpal tunnel syndrome.

The review found that landmark-guided corticosteroid injection into or near the carpal tunnel likely improved symptoms at 3 months or less (standardized mean difference [SMD] = −0.77; 95% CI, −0.94 to −0.59; eight RCTs; n = 579; moderate-certainty evidence) and at greater than 3 months (SMD = −0.58; 95% CI, −0.89 to −0.28; three RCTs; n = 234; moderate-certainty evidence) compared with no treatment or placebo injection. Functional improvement also was shown at 3 months or less (SMD = −0.62; 95% CI, −0.87 to −0.38; seven RCTs; n = 499; moderate-certainty evidence) compared with no treatment or placebo injection.