Which Technique for Treatment of Chronic Thumb MCP Joint Instability? Comparison of 3 Techniques With a Mean Follow-up of 84 Months

Abstract

Objective: Injuries to the thumb collateral ligament are common whose acute surgery gives good functional results. But they are often unrecognized and surgical procedures for chronic instability are still being discussed. The aim of this study was to compare retrospectively the clinical and radiological results of the 3 main treatments for chronic instability of the metacarpophalangeal (MCP) joint of the thumb to identify trends and optimize outcome. Materials and Methods: In this retrospective and monocentric study, we included all the patients operated between 2000 and 2012 from a chronic posttraumatic instability of the MCP joint of the thumb by 1 of 3 techniques: primary repair (37 cases), ligament reconstruction (14 cases), and arthrodesis (43 cases). Patients with hyperextension instability, degenerative instability, and a follow-up less than 2 years were excluded from this study. Subjective and objective results and rates of complications and recurrence were compared at end of the follow-up. Results: Sixty-seven patients were included, 55 followed up for a mean 84 months (range, 24-164 months). Whichever the procedure, all patients considered themselves improved or healed. Forty-eight patients (87.3%) were satisfied or very satisfied. The relief of pain was significantly better in the arthrodesis group. The mean Quick Disabilities of Arm, Shoulder and Hand (QuickDASH) for primary repair group were 17.4 (0-89.5), for ligament reconstruction group 25.7 (0-58.3), and for the arthrodesis group 17.8 (0-50). Pinch strength, on average of the value on the unoperated side, was 89% for primary repair group, 84% for ligament reconstruction group, and 94% for the arthrodesis group. Six of 10 ligament reconstructions had MCP joint laxity at end of follow-up. There were significantly fewer patients who considered themselves cured in the ligament reconstruction group. There were 4 failures by end of follow-up: 1 associated with primary repair, 1 with arthrodesis, and 2 with ligament reconstruction. Discussion and Conclusion: Surgery in treating chronic instability of the MCP joint of the thumb gives generally good results. Primary repair should be considered as much as possible. In contrast to literature report, ligament reconstruction does not give better results than arthrodesis.