Corticosteroid injection with or without thumb spica cast for de Quervain tenosynovitis.

PURPOSE To compare the corticosteroid injection (CSI) with or without thumb spica cast (TSC) for de Quervain tendinitis. METHODS In this prospective trial, 67 eligible patients with de Quervain tenosynovitis were randomly assigned into CSI + TSC (33 cases) and CSI (34 cases) groups. All patients received 40 mg of methylprednisolone acetate with 1 cc lidocaine 2% in the first dorsal compartment at the area of maximal point tenderness. The primary outcome was the treatment success rate, and the secondary outcome was the scale and quality of the treatment method using Quick Disabilities of Arm, Shoulder and Hand and visual analog scale scores. RESULTS The groups had no differences in mean age, sex, and occupation. The visual analog scale and Quick Disabilities of the Arm, Shoulder and Hand scores were similar in both groups before the treatment. The treatment success rate was 93% in the CSI + TSC group and 69% in the CSI group. Although both methods improved the patients' conditions significantly in terms of relieving pain and functional ability, CSI + TSC had a significantly higher treatment success rate. CONCLUSIONS The combined technique of corticosteroid injection and thumb spica casting was better than injection alone in the treatment of de Quervain tenosynovitis in terms of treatment success and functional outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic II.