Arthroscopic Thermal Capsular Shrinkage with Open Dorsal Radiocarpal Ligament Tensioning for Palmar Midcarpal Instability: Surgical Technique and Preliminary Outcomes.

Background: Palmar midcarpal instability (PMCI) is often neglected in diagnosis and lacks a gold standard treatment. It is primarily associated with dorsal radiocarpal (DRC) ligament insufficiency. We used a combined approach of arthroscopic thermal capsular shrinkage and open DRC ligament suture tensioning for symptomatic PMCI and present our outcomes. Methods: From 2018 to 2022, nine PMCI patients (mean age: 32 years) underwent this treatment. The mean symptom duration was 15.3 months, with a mean follow-up of 16.8 months. Outcomes were measured by wrist ROM, grip strength, VAS for pain, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and modified Mayo Wrist scores. Results: All patients showed significant improvement in pain, grip strength and function, with maintained radiocarpal stability at final follow-up. Although wrist ROM showed mild limitation after surgery, all patients returned to their previous work and activities. Conclusions: This approach may provide an effective and less aggressive treatment for PMCI. Level of Evidence: Level IV (Therapeutic).