Investigating the Effect of Triamcinolone Local Injection on Clinical Outcomes of Patients With Radial Tunnel Syndrome: A Placebo-Controlled Clinical Trial.

Purpose: The role of corticosteroid injection for radial tunnel syndrome (RTS) has not been studied in a placebo-controlled clinical trial. The present clinical trial aimed to evaluate the effect of local triamcinolone injection on pain intensity, upper-extremity disability, and elbow function of patients with RTS.

Methods: Forty-nine patients clinically diagnosed with RTS were randomized into the intervention and placebo groups. The diagnosis of RTS was made based on the following criteria: activity-related pain, maximal tenderness 3 to 5 cm distal to the lateral epicondyle, pain that worsens with forearm supination, pain radiating to the dorsoradial aspect of the forearm, and a positive Lister test. To confirm RTS, patients needed to exhibit at least four of these five criteria, with the requirement that one of the criteria be the tenderness located 3-5 cm distal to the lateral epicondyle. Patients in the intervention group received local injection of a single dose of corticosteroid (0.25 mL lidocaine 1% and 1 mL triamcinolone 40 mg/mL), and the placebo group received injection of single dose of normal saline (0.25 mL lidocaine 1% and 1 mL normal saline). The clinical outcomes, including QuickDASH (Disabilities of the Arm, Shoulder, and Hand), visual analog scale for pain, and Oxford Elbow Score, were evaluated before treatment, as well as 2 weeks and 3 months after the injection.

Results: Visual analog scale pain score, QuickDASH score, and Oxford Elbow Scores were similar between the intervention and placebo groups at 2 weeks and 3 months of follow-up. However, reduction in visual analog scale pain, QuickDASH score, and Oxford Elbow Scores were statistically significant over time among both groups.

Conclusions: Triamcinolone injection does not have any superior effect on the clinical outcomes of patients with RTS, compared with placebo.

Type of study/level of evidence: Therapeutic II.