Also called “Skier’s Thumb” and “Gamekeepers Thumb,” injury to the Ulnar Collateral Ligament (UCL) of the thumb jeopardizes the strength of the ligament and its ability to secure the bones at the base of the thumb (metacarpophalangeal or MCP joint) and prevent the thumb from extending out too far away from the hand.

This type of injury is defined as an acute injury when it occurs as the result of stress placed on the ulnar collateral ligament from an extreme force (valgus force) – such as that experienced when the thumb is caught in a ski pole during a fall. In this situation the ligament undergoes an exaggerated stretch and often tears as a result.

Those at Risk
When a repetitive activity or sport eventually leads to the loosening of the ulnar collateral ligament over time, it is referred to as a chronic injury. Often times tennis players and baseball players will experience this.

Those suffering from this type of injury generally experience some instability and difficulty griping things tightly. Though those with an acute tear of the UCL report pain and swelling directly over the torn ligament at the base of the thumb.

Both a physical examination and X-ray are done to confirm diagnosis and determine the extent of the injury. A valgus stress test is also performed in order to check the strength of the ligament and corresponding stability of the joint.

Depending on the extent of the injury and other patient factors, either a thumb spica cast will be used to stabilize and encourage healing for approximately four to six weeks – followed by range of motion exercises to strengthen grip – or surgery is recommended

Surgery is considered in the case of a complete tear (rupture) of the ligament and evidence of significant instability. It is usually done several weeks following the injury and is considered an outpatient procedure. Patients generally see results within four weeks following the surgery and regain thumb strength. Occasionally the MCP joint continues to be unstable and causes pain during pinching or grasping activities. Since chronic instability and looseness of the thumb eventually results in the development of arthritis, other procedures may be considered – including grafting in new tissue to reconstruct the ligaments, or arthrodesis in order to fuse the joint.