Skier's thumb Gamekeeper's thumb / ulnar collateral ligament injury

In skier's thumb, a ligament is damaged in the thumb joint. The symptoms usually develop following dislocation of the thumb. This can occur as the result of a fall or if the thumb is bent outward after being hit by a ball when playing sport.

Skier's thumb is the most common arm injury in skiers. The name is somewhat confusing, as the symptoms can also occur in other sports and activities. Specialists therefore prefer to use the term "collateral ulnar ligament injury".

The joint in the thumb that is affected is called the MCP-I joint. This is the joint where the thumb originates from the hand. The MCP-I joint is supported by a capsule and ligaments on all sides. These structures provide robustness and prevent incorrect movement of the joint. The joint ligament that is located on the inside of the thumb is called the "collateral ulnar ligament" of the MCP-I joint. It is this joint ligament that is damaged in skier's thumb.

The collateral ulnar ligament may sprain or tear if the thumb is struck by a significant force that is directed outward. If the joint ligament tears completely this is called a "rupture". The thumb can then make abnormal outward movements, because the collateral ulnar ligament is no longer blocking these movements.

A classic cause of skier's thumb is a fall while skiing during which the thumb hooks behind the ski pole. Hockey players can suffer the same injury by falling with a hockey stick in their hand. Another cause is when the outstretched thumb is hit by a ball while playing sport and the thumb is then "bent" too far outward.

These symptoms may not be caused by a trauma (accident or fall). Activities that involve repetitive stretching of the collateral ulnar ligament can also cause damage to the joint ligament. This is the reason that it is also referred to as "gamekeeper"s thumb"; In the past, hunters used a brief movement of the thumb to twist the neck of birds or rabbits. This repetitive movement causes damage to the collateral ulnar ligament.

The healthcare professional asks about the complaints and how they have arisen. During the physical examination, swelling, tenderness, mobility, and stability of the thumb are assessed.

Because a skier's thumb is often accompanied by an avulsion fracture, taking an X-ray is often necessary. The size of the torn-off bone fragment determines whether surgery is needed or not. With an ultrasound, it can quickly become clear what the damage to the ligament is. An MRI provides the best view of the thumb, but the result often takes longer.

If the collateral ulnar ligament is only partially damaged it will probably heal spontaneously. If this is not the case, a number of treatment options may be considered depending on the severity of the injury:

• Physiotherapy or hand therapy.
• Immobilization for 3 - 4 weeks using a splint or cast.
• Surgical repair of a completely ruptured collateral ulnar ligament.

Verhaar, J.A.N. & Linden, A.J. van der (2005) Orthopedie Houten: Bohn Stafleu van Loghum.
T.A.R. Schreuders (2006) Richtlijn behandeling skiduim Handen Team Zeeland.