Hydrodissection With Neuroprolotherapy Versus Open Release for Carpal Tunnel Syndrome (HN-CTS)

This study is a randomized controlled, parallel-group, non-inferiority trial designed to compare ultrasound-guided hydrodissection combined with neuroprolotherapy versus open carpal tunnel release in patients with carpal tunnel syndrome. The study will be conducted at a tertiary referral center. Eligible participants will be adults with a clinical diagnosis of carpal tunnel syndrome who meet predefined inclusion and exclusion criteria.

Participants will be randomly allocated in a 1:1 ratio to either the experimental or control group using a computer-generated randomization sequence. Allocation concealment will be ensured through the use of sequentially numbered, sealed, opaque envelopes prepared by an independent researcher. Outcome assessment and statistical analysis will be performed by blinded evaluators to minimize detection bias.

The experimental group will undergo a single session of ultrasound-guided hydrodissection combined with neuroprolotherapy. The procedure will be performed under sterile conditions with real-time ultrasound guidance. A needle will be positioned adjacent to the median nerve at the level of the carpal tunnel, followed by perineural injection of a solution composed of zero point nine percent sodium chloride and five percent dextrose, combined with local anesthetic and betamethasone, with a total volume of approximately ten milliliters. The objective of the intervention is to achieve mechanical separation of the median nerve from surrounding structures and to promote modulation of the local inflammatory environment. The procedure duration is expected to be approximately fifteen to twenty minutes. Post-procedure care will include the use of simple analgesics and guidance for gradual return to daily activities.

The control group will undergo open carpal tunnel release, performed in an operating room under sterile conditions. The procedure will be conducted using local or regional anesthesia and involves a longitudinal palmar incision, identification and division of the transverse carpal ligament to decompress the median nerve, followed by hemostasis, layered closure, and application of a compressive dressing. The procedure duration is expected to be approximately twenty to thirty minutes. Standardized postoperative care will include analgesia, wound care, early finger mobilization, and suture removal between ten and fourteen days.

Participants in both groups will be evaluated at baseline, and at 1, 3, and 6 months after the intervention. The primary outcome is the change in the Boston Carpal Tunnel Questionnaire score at 3 months. A non-inferiority margin of 0.5 points will be used to determine whether the experimental intervention is not clinically worse than surgical treatment.

Secondary outcomes will include pain intensity measured by the visual analog scale, grip strength assessed by dynamometry, pinch strength measured using pinch dynamometry, median nerve cross-sectional area assessed by high-resolution ultrasound, time to return to work based on patient self-report, and procedure-related complications recorded during follow-up.

Statistical analysis will be performed according to the intention-to-treat principle, including all randomized participants in the groups to which they were allocated. A per-protocol analysis will also be conducted as a sensitivity analysis. Continuous outcomes will be compared between groups using analysis of covariance models adjusted for baseline values. Longitudinal data across multiple time points will be analyzed using mixed-effects models to account for within-subject correlation over time.

The non-inferiority hypothesis will be tested by comparing the confidence interval of the between-group difference with the predefined non-inferiority margin. If the upper bound of the confidence interval does not exceed the margin of 0.5 points in the Boston Carpal Tunnel Questionnaire score, non-inferiority will be concluded.

This study aims to determine whether a minimally invasive, ultrasound-guided intervention can provide comparable clinical outcomes to open surgical decompression while potentially offering advantages in terms of reduced invasiveness, faster recovery, and lower complication rates.