Efficacy of Ultrasound-Guided Particulate Versus Nonparticulate Steroid Injection in Carpal Tunnel Syndrome: An Open-Label Randomized Control Trial

Introduction Perineural corticosteroid injection is an extensively used and accepted treatment for carpal tunnel syndrome (CTS). However, to this date, there is no guideline as to which corticosteroid has to be used as the standard treatment for CTS. Triamcinolone acetonide is a commonly used particulate steroid that can cause permanent nerve injury if it is accidentally injected into the nerve. Conversely, dexamethasone sodium phosphate is a nonparticulate steroid that would not cause permanent nerve damage following accidental injection. Methods Mild to moderate cases of CTS, confirmed by nerve conduction studies (NCS), with symptoms greater than three months were recruited. The participants received one session of ultrasound-guided perineural injection by the in-plane axial ulnar-sided approach with 4 mL of either dexamethasone (dexamethasone sodium phosphate 8 mg (2 mL) + 2 mL 0.5% bupivacaine) or triamcinolone (triamcinolone acetonide 40 mg/mL (1 mL) + 2 mL 0.5% bupivacaine + 1 mL normal saline) solution. The parameters assessed were Phalen's test time (in seconds), visual analog scale (VAS), and Boston carpal tunnel questionnaire (BCTQ) scores at baseline and two and four months, and NCS changes in sensory nerve conduction velocity (SNCV) and distal motor latency (DML) of the median nerve at baseline and four months. Statistical analysis was conducted using the software SPSS version 26.0 (IBM Corporation, Armonk, NY, USA). Independent samples t-test was used for comparison between groups and the paired t-test for improvement within each group. P values < 0.05 were considered statistically significant. Results The mean age was 42.64 +/- 10.99 in the dexamethasone and 45.22 +/- 10.602 in the triamcinolone group cases (P = 0.324). There were 58 females (84.06%) and 11 males (15.94%). Each of Phalen's test time, VAS, and BCTQ scores significantly improved within both dexamethasone and triamcinolone groups at the second and fourth months after injection (P < 0.05). The NCS parameters (SNCV and DML) also significantly improved in both groups at the fourth month after the injection (P < 0.05). However, there were no significant differences in the improvement of Phalen's test time between the two groups (P = 0.745), VAS score (P = 0.319), BCTQ score (P = 0.137), SNCV (P = 0.511), or DML (P = 0.753). Postprocedural pain lasted significantly longer in the triamcinolone group (P < 0.05). No major complications were noted in either of the two groups. Conclusion Dexamethasone is as effective as triamcinolone in improving the symptoms of CTS and can be used as a safer and more effective alternative in the treatment of mild to moderate CTS cases.