Comparison of Corticosteroid Injection, Nighttime Splinting, or Their Combination for Initial Treatment of Moderate-to-Severe Carpal Tunnel Syndrome

Nighttime splinting for 6 weeks.

Local corticosteroid injection (triamcinolone acetonide 40mg). A single injection of triamcinolone acetonide 40mg mixed with an equal volume of 1% lidocaine is administered. The injection is performed under ultrasound guidance and anatomical landmarks to target the proximal carpal tunnel. With the wrist extended, the needle is typically inserted on the ulnar side of the palmaris longus tendon, approximately 1 cm proximal to the wrist crease. If blood is aspirated or the patient reports paresthesia (which usually indicates nerve irritation), the injection site should be adjusted.

6 weeks later, all patients will undergo evaluation of their initial treatment. Further therapeutic decisions will be made based on physician assessment, including: continuing nighttime splinting, administering corticosteroid injections to patients who initially received only the splint, adding nighttime splinting for patients initially received only corticosteroid injections, and transitioning from nighttime splint use to continuous wear. Subsequently, evaluations will be conducted every 6 weeks, with dynamic adjustments to the treatment plan. Corticosteroid injections will be administered at least 24 weeks apart, and the second injection dosage may be adjusted based on the patient's condition, with a maximum dose of 80mg. Throughout the study period, physicians will perform electrophysiological examinations according to changes in patients' clinical status.