Comparison of Ultrasound-Guided Perineural 5% Dextrose Prolotherapy and Corticosteroid Injection in Mild to Moderate Carpal Tunnel Syndrome: A Retrospective Clinical Study

Objective: Carpal tunnel syndrome (CTS) is a common entrapment neuropathy caused by median nerve compression. Steroid injections provide temporary relief in mild to moderate CTS, whereas 5% dextrose prolotherapy (PrT) has recently emerged as a regenerative alternative. This study compares the efficacy of ultrasound-guided perineural 5% dextrose PrT and corticosteroid injections. Methods: In this retrospective analysis, 74 individuals aged between 18 and 70 years, meeting both clinical and electrophysiological criteria for mild to moderate CTS, were included. 36 patients received a single ultrasound-guided injection of 40 mg triamcinolone acetonide (steroid group), while 38 patients underwent three perineural 5% dextrose PrT sessions at three-week intervals (PrT group). All patients followed a 12-week conservative protocol with wrist splinting and nerve/tendon gliding exercises. Outcomes were assessed at baseline, week 6, and week 24. The primary outcome was Visual Analog Scale (VAS) pain and numbness score. Secondary outcomes were QuickDASH, grip and pinch strengths, and median nerve conduction studies. Results: Both groups showed significant within-group clinical and functional improvements (p<0.05). At 6 weeks, the steroid group showed higher grip strength compared with PrT (MD = -1.25, 95% CI -4.12 to 1.62, p = 0.048) and pinch (MD = -0.32, 95% CI -0.87 to 0.23, p = 0.005) compared with the prolotherapy group. At 24 weeks, PrT resulted in lower daytime pain VAS compared with steroids (MD -1.15, 95% CI -2.23 to -0.07, p = 0.026), surpassing the minimal clinically important difference (MCID) for CTS pain reduction. Electrophysiological improvements occurred only in the steroid group, especially in motor and sensory conduction parameters, without corresponding long-term clinical superiority. Conclusion: Perineural PrT and steroid injections appear to be effective non-surgical options for managing mild to moderate CTS. While steroids may provide faster symptom relief and earlier improvements in strength, dextrose PrT demonstrated more sustained pain reduction. It should be noted, however, that the injection protocols differed-the steroid group received a single dose, whereas the PrT group underwent three sessions-an approach based on our review of the existing literature. This discrepancy should be considered when interpreting the results. Further randomized controlled trials are needed to confirm these findings and clarify the regenerative mechanisms of dextrose prolotherapy.