Comparison of Ultrasound-guided Transverse Carpal Ligament Release via Different Approaches in Carpal Tunnel Syndrome: A Prospective, Randomized, Controlled Trial.

Background: Ultrasound-guided transverse carpal ligament (TCL) needle release has been demonstrated to be an effective treatment for carpal tunnel syndrome (CTS). However, no existing evidence has investigated the comparative efficacy of different release approaches.

Objective: To compare the efficacy of ultrasound-guided TCL needle release via different approaches for patients with mild to moderate CTS over a 12-month follow-up.

Study design: A prospective, randomized, controlled trial.

Setting: Outpatient clinic at a university hospital.

Methods: Sixty-four patients with mild to moderate CTS (> 3 months' duration) were randomly assigned to either the long-axis group (one session of ultrasound-guided corticosteroid injection plus long-axis TCL needle release) or the short-axis group (one session of ultrasound-guided corticosteroid injection plus short-axis TCL needle release) in a one-to-one ratio. The primary outcomes were the symptom severity scale (SSS) and functional severity scale (FSS) scores of the Boston Carpal Tunnel Questionnaire (BCTQ). The secondary outcomes were electrophysiological studies, including distal motor latency (DML) and sensory nerve conduction velocity (SNCV), cross-sectional area (CSA) of the median nerve (MN), and patient-reported successful clinical response. Assessments were performed before treatment and at one, 3, 6, and 12 months after treatment.

Results: A total of 60 patients (30 per group) completed the trial. Compared to the baseline, both groups exhibited improvement in SSS, FSS, SNCV, DML, and CSA at all follow-up time points, with statistical differences for SSS, FSS, and SNCV at 3, 6, and 12 months (P < 0.05), DML at 6 and 12 months (P < 0.05), and CSA at each follow-up time point (P < 0.05). Compared to the short-axis group, the long-axis group exhibited more improvement in SSS and FSS at all follow-up time points, with statistical differences at 3, 6, and 12 months (P < 0.05), and in SNCV and DML at 6 and 12 months (P < 0.05). Although the long-axis patients exhibited more improvement in their wrists' CSAs, the intergroup differences were nonsignificant at all follow-up time points (P > 0.05). Four patients in the short-axis group experienced recurrent symptoms and underwent surgery at 12 months, whereas no recurrence was observed in the long-axis group.

Limitations: A relevant future trial with a longer follow-up period than this one used is still necessary.

Conclusions: Ultrasound-guided TCL needle release via the long-axis approach appears to be more effective than the short-axis approach for treating mild to moderate CTS.