The term skier’s thumb refers to acute ulnar collateral ligament (UCL) injuries of the thumb which can occur when a skier falls on an open hand or the ski pole is forcibly twisted out of the hand. These injuries often consist of forceful combined radial deviation and hyperextension of the thumb (the thumb bends backwards). To decrease your risk of injury, release your grasp on the ski pole when you fall or consider using strapless poles.
The radial and ulnar collateral ligaments (RCL and UCL) along with the volar plate are the primary stabilizers of the small joints of the thumb and fingers. The ligaments of the thumb and fingers provide stability for functional use of the hand. Without the stability provided by these structures, manipulation and grasp would be difficult. The ability for pinching and grasping of large objects is dependent on intact ligaments at the thumb MP joint.
The most commonly injured ligaments in the thumb are the collateral ligaments of the metacarpophalangeal (MCP) joint. UCL injuries are far more common than RCL injuries. Common terminology for injuries to the UCL include skiers thumb or gamekeepers thumb. The term gamekeepers thumb often refers to an injury due to a chronic strain on the UCL historically seen in Scottish gamekeepers twisting the head of wounded rabbits. This term is generally reserved for reference to chronic UCL injuries.
A UCL tear can be partial or full. A full tear often has a Stener lesion. When this occurs, the torn ligaments slide out from the adductor muscles and become trapped superficially. During your exam, your physician may exam/palpate your thumb for tenderness and pain at the area of the ligament injury, stress test for stability with the thumb in several different positions and order radiography.
Type I and II UCL injuries are incomplete sprains, whereas, type III is a complete rupture of the ligament. Grade I and II sprains as well as minimally displaced avulsion fractures may be treated in a hand based thumb orthotic which allows for some thumb motion.
Your physician may keep you in the orthotic for 1-2 weeks depending on the severity of your injury. You will then begin working on regaining pain free movement at the thumb joint, gradually progressing to strengthening activities. Certain pinch and grasp motions are avoided for approximately 8 weeks.
Ligament avulsions will require surgical repair. If the ligament is partially torn and the joint has only minimal instability, the physician may immobilize the thumb in a splint or cast. A displaced avulsion fracture occurs when there is a complete tear in conjunction with a fracture. In this case, hardware (wires,screws or bone anchors) may be used to stabilize the fracture as well as repair the ligament. The thumb will likely be immobilized for 4 weeks after surgery. Once the hardware is removed protected range of motion activities will be initiated with anticipated return to full activity at around 3 months. While recovering from this injury, one must remember that effective thumb function is more dependent on thumb stability than mobility therefore, aggressive activity should be avoided until ordered by your physician or therapist.