What is a shoulder dislocation?
The shoulder is the most mobile joint in the body. Because of this, it is also the joint at greatest risk for instability due to athletically-induced trauma. A shoulder dislocation is a frequent injury amongst contact and collision athletes such as football players. Normally, there is direct contact between the humerus (arm bone) and glenoid (shoulder socket). The term ‘dislocation’ implies a complete loss of contact between these two bones. ‘Subluxation’ refers to the partial loss of contact between these bones. Shoulder dislocations occur when the humerus is forced out of the glenoid cavity, usually following a fall on the out-stretched arm or when the arm is pulled awkwardly while in an over-head position, such as when a quarterback’s throwing arm is blocked in its forward motion by a defensive player attempting to block the pass. When the shoulder dislocates, there is typically a tear of a structure known as the labrum (meaning “lip” in Latin). This cartilage ‘lip’ surrounds the shoulder socket and aids in providing stability to an otherwise mobile joint. Ninety-five percent of all shoulder dislocations occur in a forward direction (anterior dislocation). However, offensive linemen are most at risk for a dislocation in a backward direction (posterior dislocation).
Shoulder dislocations can occur to both the dominant and non-dominant arm. The risk for recurrence is predicated on two primary factors: age and activity level. Younger athletes (less than 25 years of age) and those who are very active in sports have the highest risk for recurrence. Therefore, football players of all ages are at risk for recurrent shoulder instability.
How is a dislocated shoulder diagnosed?
An athlete who experiences a dislocated shoulder will develop immediate pain and an inability to move the arm. Typically, the player holds his arm at the side. There is usually a deformity of the shoulder with fullness that can felt by the examining athletic trainer or physician.
There are usually no other significant injuries; however, shoulder dislocations in older patients can result in a tear of the rotator cuff tendon that may also require treatment. Plain x-rays are always obtained in a player suspected of having a dislocated shoulder. Not only will x-rays confirm the presence and direction of the dislocation, but they will also help rule out the existence of any other fractures. Unfortunately, plain x-rays only show bone injury. An MRI (magnetic resonance image) can also be useful in diagnosing the extent of soft-tissue damage to the labrum, muscles, tendons, and cartilage in and around the shoulder joint.
What are the treatment options for a dislocated shoulder?
An experienced physician who suspects an athlete has a dislocated shoulder will usually be able to make the diagnosis based on the mechanism of injury and physical examination. The first step in the treatment of an athlete with a dislocated shoulder is to replace (reduce) the humerus back into the glenoid socket. This reduction as it is called can usually be accomplished with gentle traction of the arm while pressure is applied to the dislocated joint. Once the joint is reduced, the player’s arm is placed in a sling for comfort and support. There is some controversy as to the optimal definitive treatment for the player who has his first dislocation. Most experts now recommend conservative (non-operative) treatment for the initial episode. Physical therapy consisting of range of motion exercises and progressive strengthening activities is always prescribed. This usually allows the athlete to return to play within 4-6 weeks. A brace may be used that can be worn under the shoulder pads to aid in preventing a recurrence. Unfortunately, these braces restrict the player’s motion and, therefore, cannot be used by those players whose position necessitates overhead motion (i.e. wide receiver).
Surgery is recommended for the player who experiences multiple dislocations or who chooses to undergo surgical stabilization following the first episode. Historically, surgical repair was done through an open incision. Now, this procedure is most commonly performed arthroscopically. The labrum that is torn is repaired back to the bone socket using a variety of either metal or plastic anchors in order to reestablish stability of the joint. Following surgery, the athlete is kept in a sling for four to six weeks. Physical therapy is prescribed to regain shoulder motion, strength, and return to football-related activities.
When can an athlete return to sports following a dislocated shoulder?
Most football players who dislocate their shoulder for the first time can usually return to play within six weeks of the injury once they reestablish full range of shoulder motion and strength. They must be able to perform all of the actions necessitated by their position prior to return to play. Those players who undergo surgery usually require five to six months of rehabilitation before they are able to resume contact and collision sports.
What is the success rate for treating a dislocated shoulder?
Non-operative treatment of a football player who dislocates his shoulder for the first time has up to a 50% failure rate due to the high forces experienced by the shoulder in these activities. This explains why a significant number of these athletes ultimately require surgery in the off-season for definitive treatment. The success rate of surgical repair of a dislocated shoulder is reliably greater than 90%. This success is defined as no further episodes of instability with the ability to resume strenuous activity.