Shoulder instability in athletes.

Define shoulder instability and identify the most common causes of shoulder instability in athletes. Shoulder instability encompasses a wide spectrum, from complete dislocations that require manual reduction to microinstability in throwers. When we looked prospectively at West Point cadets, we found that 80% of instability events were subluxations (no manual reduction performed).1 We found that even first-time traumatic subluxation events could cause Bankart lesions (transient luxations)2 similar to complete dislocations.3 Therefore, we recommend a high index of suspicion for subluxations and early magnetic resonance imaging in athletes. Shoulder instability is common in athletes, and the incidence increases with the amount of player contact. Therefore, the highest rates have been reported in the collision sports: football, hockey, rugby, and wrestling.