Recovering from a Traumatic Shoulder Dislocation
Written by Scott A. Hacker, M.D.

Shoulder Anatomy
The shoulder joint consists of the humeral head (the ball at the end of the upper arm) and its connection with the glenoid (the socket). There are 4 major muscles that connect the humeral head to the glenoid of the scapula called the ‘rotator cuff’. These muscles start on the scapula, or wing bone, and their tendons (which connect muscle to bone) attach to the humeral head. The rotator cuff tendons pass under the acromion. When these tendons contract they allow us to raise or rotate our shoulder. Other larger muscles, like the deltoid and pectoralis cover the rotator cuff and provide the contour of the shoulder that we see.

The shoulder allows for the greatest range of motion of any joint. The glenoid is a relatively shallow socket made deeper by a rim of tissue called the labrum. The labrum attaches to the capsule of the shoulder. The capsule hold the fluid in the joint and helps provide more stability. The rotator cuff tendons help provide stability as well, pulling the humeral head deeper into the socket.

How does a shoulder dislocate ?
Most (about 90%) of dislocations occur when the ball slips out the front of the socket. This happens when the arm is forced back while it is rotated out and held overhead, like when a volleyball player serves overhead. More rarely, the shoulder can dislocate out the back, often with a forceful blow to the arm pushing it out. Typically, a true dislocation is quite painful and requires a trip to the emergency room to have it ‘put back in’.

How can I prevent my shoulder from dislocating again ?
The majority of stability in the shoulder is provided by the capsule and labrum. Once torn, the capsule rarely heals back to normal. Fortunately, some dynamic stability is provided by the rotator cuff muscles. This means that to reduce the risk of another dislocation, the best we can do is strengthen the rotator cuff muscles and avoid those positions that dislocate the shoulder again.

The risk of dislocating the shoulder again is based on the age of the person at the time of first dislocation. As a general rule, a dislocation under age 20 runs a 90% risk of re-dislocation. On the contrary, the risk of someone over 40 years old redislocating is less than 10%! This age group, however, is more prone to have a rotator cuff tear along with a dislocation.

What is the rehabilitation like ?
Typical rehabilitation programs start with a short period of immobilization with a sling, and then progress to exercises that restore a range of motion and strengthen the rotator cuff. The rehab protocols you may participate in have been carefully designed to get you back to your activities as quickly as possible with the strongest, most stable shoulder you can attain

When do I need surgery ?
Shoulder instability can be quite disabling. While a forceful injury usually leads to the initial dislocation, it may take less and less for your shoulder to come out. The need for surgery depends on your functional needs and degree of instability.

Surgery is usually a last resort when a conservative program of exercise and therapy has failed, unless the patient is very young and involved in high risk sports. Certain sports, like kayaking, hang gliding or rock climbing depend on a functional shoulder and a dislocation at the wrong time could be life threatening.

What’s involved with the surgery ?
The technical goal of surgery is to restore the normal anatomic relationship of the capsule and labrum to the glenoid, or socket of the shoulder. This can be done arthroscopically using advanced reconstructive techniques, or with an open incision in front of the shoulder, which has been the classic technique for many years. Stretched tissues are also repaired at the time of surgery.

Open techniques may slightly decrease the external rotation of the shoulder, but typically have a lower long term redislocation rate after surgery than arthroscopic techniques.
Restoration of stability while maintaining mobility of the shoulder with pain-free range of motion is the ultimate goal. The orthopaedic literature cites success rates from 85 to 95% with open and arthroscopic techniques.

Be sure to ask your doctor all your questions about shoulder dislocation, various kinds of treatment, rehabilitation and risks. Everyone is different with different problems, requiring a customized treatment program.

What are the risks of surgery ?
While rare, there are risks with any operation. Failure of the reconstruction can occur in up to 10% of cases, depending on the repair technique. This could mean further dislocating episodes requiring further surgery. Other risks include infection, bleeding, nerve injury, and limitations in activity. Your doctor will explain the risks involved to you before any treatment plan is made.