Mechanism of Injury
“Skier’s thumb” represents an injury to the ulnar collateral ligament of the metacarpophalangeal (MCP) joint of the thumb. As the eponym implies, it can be secondary to a fall while skiing, when the thumb is forcibly radial deviated when the hand is caught in a ski pole. These injuries can also occur secondary to any injury, such as a fall, which stresses the ulnar collateral ligament of the thumb MCP joint.
These injuries can usually be diagnosed on physical exam alone. Patients present with pain and swelling along the ulnar aspect of the MCP joint of the thumb. The MCP joint should be manually stressed, to determine if the injury has resulted in instability, usually necessitating surgery.
Radiographs should be evaluated in all patients, to rule-out an associated ligamentous avulsion fracture. Stress radiographs may be helpful in determining potential instability. If there is any question as to the diagnosis, or to the extent of the ligamentous injury, an MRI should be obtained.
If the ligamentous injury is found to be stable on stress testing, it can be treated with either a removable thumb spica splint or cast for approximately four weeks. Unstable injuries, or those with displaced avulsion fractures, usually require surgical repair. This is most often performed by reattaching the ruptured ligament employing a suture anchor. The thumb is then immobilized for approximately four weeks postoperatively. If the injury is diagnosed late, after about three to four weeks, the ligament usually requires reconstruction with a tendon graft.
The incidence of these injuries can be decreased by newer ski pole designs, and proper technique and wrist/hand guards.