Repair of Thumb Metacarpophalangeal Joint Ulnar Collateral Ligament Injuries With Microanchors

Abstract

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. The present study evaluated prospectively the functional results of 27 patients who had open repair of the UCL of the thumb using microanchors either acutely or delayed (up to 9 weeks postinjury). 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 used to suture the proximally based flap after temporary pinning of the MCP joint. 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 comparing with the untreated thumb, allowing all patients to return to preinjury activities, including sports, except one (96% of cases). At final follow-up, radiographs showed no implant complications, no osteoarthritic changes in MCP joints, and stress testing showed that all patients had normal stability in the treated thumb when compared with the untreated thumb. Only 2 patients complained of a lumpy swelling at the ulnar aspect of the MCP joint, one of which was tender. 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.