The Figure-of-Eight Ligament Reconstruction in Thumb Carpometacarpal Instability: Surgical Technique and Clinical Outcomes

Abstract

Purpose: This study reviewed the results of the figure-of-eight ligament reconstruction, a technique used in the surgical management of thumb carpometacarpal (CMC) instability. This technique establishes joint stability through forces originating within the CMC joint, providing volar and dorsal support.

Methods: We evaluated the outcomes of 15 patients with nontraumatic, nonarthritic thumb CMC instability treated with the figure-of-eight ligament reconstruction technique. This technique involves routing a graft of the palmaris longus tendon through the base of the first metacarpal and trapezium bone in a figure-of-eight fashion. Preoperative visual analog scale (0-100) for pain and Michigan Hand Outcomes Questionnaire total scores were compared with 3- and 12-month postoperative scores. Secondary outcomes included strength, range of motion, patient satisfaction, return to work, and complications.

Results: A significant improvement between intake and 12 months after surgery was observed for both Michigan Hand Outcomes Questionnaire total scores (53, SD 3 vs 70, SD 4) and visual analog scale pain scores (63, SD 4 vs 36, SD 7). Additionally, after surgery, restored thumb CMC joint stability was reported for all patients. Strength and range of motion improved between intake and 12 months after surgery. The median return to work was 6 weeks. Nine (60%) patients rated their satisfaction as "excellent" or "good," and 11 (73%) patients said that they would undergo the surgery again.

Conclusions: The figure-of-eight ligament reconstruction significantly improves pain and function in patients with thumb CMC instability while restoring joint stability and preserving range of motion, making it a suitable technique.

Type of study/level of evidence: Therapeutic IV.

Keywords: Figure-of-eight; ligament reconstruction; thumb carpometacarpal instability; trapeziometacarpal joint.