Acute ulnar collateral ligament injury in the athlete.

The functional thumb is a necessity for successful athletic participation. It not only allows the athlete to manipulate athletic equipment but also allows the precise manipulation of objects in the athlete's hand. Injury to the thumb often negates power grip and finesse of the athletic hand. Injuries can range from fractures, to dislocations, to ligamentous injuries. The relatively unconstrained thumb metacarpophalangeal joint is particularly vulnerable to injury from an abduction moment to its distal segment. Such injuries occur from direct contact and with falls on equipment such as racquet handles and ski poles. The stability of the athlete's metacarpophalangeal joint must be restored to allow for a productive return to sport.