Hydrodissection With or Without Corticosteroid Versus Corticosteroid-Only Injection for Carpal Tunnel Syndrome: Double-Blind Randomized Controlled Trial.

INTRODUCTION/AIMS: Hydrodissection is an emerging technique in the management of carpal tunnel syndrome. We aimed to compare the efficacy of hydrodissection with or without corticosteroid versus intra-carpal corticosteroid injection for treating carpal tunnel syndrome.

METHODS

In total, 66 wrists with mild to moderate carpal tunnel syndrome were allocated to three study arms. Under ultrasound guidance, patients received a single injection consisting of 1 mL (40 mg) triamcinolone acetonide, 1 mL lidocaine, and 3 mL of saline, or 1 mL lidocaine, and 4 mL saline. Another group received 1 mL intra-carpal triamcinolone acetonide (40 mg) without ultrasound guidance. All participants were followed for 3 months post-injection. The primary outcome was the median nerve cross-sectional area. Secondary outcomes were symptom severity, functional status, electrodiagnostic test results, hang grip, and pain.

RESULTS

Analyses showed a significant reduction in symptom severity, improvement in function, decrease in median cross-sectional area, and improvement in electrodiagnostic evaluations for all the interventions 3 months after the injections (all p < 0.05). However, there was no significant improvement in muscle strength with any of the interventions. Sensory distal latency decreased (p ≤ 0.004), and sensory nerve conduction velocity increased in all groups (p ≤ 0.001). For motor nerve evaluations, distal latency decreased significantly with the three interventions (p ≤ 0.003), while nerve conduction velocity in the forearm segment increased in the steroid-only group (p < 0.011). Group comparisons did not reveal any significant differences.

DISCUSSION: All interventions were effective in improving symptom severity, function, and electrodiagnostic and ultrasound measures, with no significant differences observed between the treatments.

TRIAL REGISTRATION: The trial was registered prospectively at the Iranian Registry of Clinical Trials website http://www.irct.ir/, a WHO Primary Register set up with the registration number IRCT20210613051566N1.