Repair of ulnar collateral ligament injuries of thumb metacarpophalangeal joint with microanchors

Abstract

Background Ulnar collateral ligament (UCL) injuries of the metacarpophalangeal (MCP) joint of the thumb are common. Complete rupture can be a debilitating injury resulting in decreased grip and pinch strength. Purpose The present study evaluated prospectively the functional results of 27 patients who had open repair of UCL of the thumb using microanchors either acutely or delayed (up to 9 weeks postinjury). Patients and methods Through a standard S-shaped incision over the dorsoulnar aspect of the thumb, one or two 1.5- or 1.3-mm microanchors are fixed to the base of the proximal phalanx in the footprint of the avulsed ligament and are used to suture the proximally based flap after temporary pinning of the MCP joint. Results The stability, range of motion, pinch grip, and radiographs were evaluated at least 16 months after surgery. The mean time off work was 10 weeks. All patients had equal stability and normal pinch grip when compared with the untreated thumb, allowing all patients to return to preinjury activities, including sports, except one (96% of patients). During final follow-up, radiographs showed no implant complications and no osteoarthritic changes in the MCP joints, and stress testing showed that all patients had normal stability in the treated thumb when compared with the untreated thumb. Only two patients complained a lumpy swelling at the ulnar aspect of the MCP joint, one of which was tender. Conclusion Repair of UCL of the MCP joint of the thumb with this technique is an effective, durable, and safe method to allow restoration and maintenance of a stable, pain-free thumb.