Gamekeeper's thumb, also known as skier's thumb, is a tear of the ulnar collateral ligament, a band of tissue that supports the joint at the base of the thumb. Damage to the ulnar collateral ligament may lead to chronic instability of the thumb, creating problems in its normal functioning. Gamekeeper's thumb can result from sports activities (while stopping a ball with a bare hand) or a fall on your outstretched thumb (especially while holding onto something like a ski pole). Symptoms include pain, bruising and swelling at the base of the thumb. You may also experience loss of strength when pinching or gripping with the thumb.
To diagnose gamekeeper’s thumb, your doctor may numb your thumb and perform a physical examination. If the tear is associated with fracture of a bone, your doctor may order an X-ray or ultrasound.
Your doctor may suggest applying ice to reduce swelling and will prescribe pain relieving medications. For a partially torn ligament, your doctor may order a splint or cast for about six weeks followed by an exercise program to improve the thumb’s range of motion. If the ligament is completely torn, surgery is usually recommended for repair.