Intra-flexor retinaculum steroid injection in elderly patients with carpal tunnel syndrome: A randomized clinical trial.

INTRODUCTION

The efficacy of ultrasonography-guided intra-flexor retinaculum corticosteroid injection is compared to within-carpal tunnel steroid injection, for the treatment of elderly patients with carpal tunnel syndrome (CTS).

MATERIAL & METHODS: In this prospective, double-blind, randomized trial, the elderly patients with CTS are allocated 1:1 into the two treatment groups. Subjects and assessors remained blinded to group allocation throughout the trial. All patients received 40 ​mg triamcinolone (1 ​mL) plus 1 ​mL of 2% lidocaine, either fenestrated in the flexor retinaculum (group 1) or injected within the carpal tunnel between the flexor retinaculum and median nerve (group 2). Patients were instructed to use a wrist splint for two weeks post-treatment. Symptom severity, grip, electrodiagnostic indices, and ultrasonographic features were measured at baseline and 6-weeks thereafter. The primary outcomes were median nerve distal motor and sensory latencies, and those secondary outcomes were Boston Carpal Tunnel Questionnaire (BCTQ) scores, visual analog scale (VAS) pain scores, and the median nerve inlet cross-sectional area (CSA).

RESULTS

Of 92 individuals screened, 50 eligible participants were randomized, all of whom completed the study and were included in the analysis. Patients receiving the intra-flexor retinaculum injection demonstrated significantly greater improvements in their total BCTQ score (p ​= ​0.023), VAS score (p ​= ​0.026), and inlet CSA (p ​= ​0.004), while the electrodiagnostic indices and the grip scale did not differ between groups.

CONCLUSION

The intra-flexor retinaculum corticosteroid injection can provide better functional recovery and symptom reduction for elderly patients with CTS, compared to the within-carpal tunnel corticosteroid injection.