SKIER’S THUMB (ULNAR COLLATERAL LIGAMENT TEAR)
One of the most common injuries in the hand is a tear of one of the ligaments that supports the side of the thumb. Originally noted in Scottish gamekeepers, who stretched out their ligaments holding down animals, its modern name now reflects a more common mechanism of injury, falling onto the hand while skiing.
The thumb joint second closest to the tip is known as the metacarpophalangeal joint, or MP joint. On each side of the joint, there are thick bands of tissue known as the collateral ligaments that limit side to side motion. When the hand is used to break a fall (not just while skiing), the thumb is often pulled away from the fingers, severely stressing the ligament on the side closest to the index finger (referred to as the ulnar collateral ligament or UCL). The UCL can become partially torn, completely torn or detached with a fragment of bone. When the ligament is injured, people will typically experience pain, swelling and occasionally bruising around the MP joint.
The severity of a thumb ligament injury is very difficult to assess by appearance alone. If an injury is suspected, evaluation by a qualified health care professional possibly including x-rays or MRI (magnetic resonance imaging) is recommended.
If the thumb ligament is found to be injured, initial treatment usually consists of immobilization with a splint, elevation to reduce swelling and icing for comfort if needed. An evaluation by a hand surgeon is preferably done within 7-10 days of the injury. Examination of the joint to test for stability, often combined with the x-rays or MRI, will help determine the severity of the injury. Careful attention is made to assess the location of the torn end of the ligament. In some cases, the ligament is flipped back and trapped under other tissues (Stener’s lesion), potentially limiting its ability to heal properly.
Many UCL tears can be treated with simple immobilization alone. If the joint has no detectable looseness (laxity) under stress, casting or bracing of the thumb for 6-8 weeks should allow the ligament to heal and restore painless function.
If the joint feels loose or unstable under stress (especially when a Stener’s lesion is present), or if a bone fragment has been pulled off and is misaligned, surgery may be considered. In surgery, the ligament is typically stitched back together or anchored back to the bone. Any bone fragments would be realigned and stabilized as well. Surgery may involve the use of small metal implants on a temporary or permanent basis. Even with surgery, a period of immobilization is required similar to non-surgical treatment. The surgery can be done safely in an outpatient setting.