Sports and other activities that require repeated and prolonged shoulder movements can contribute to a shoulder dislocation by damaging ligaments that stabilize the joint.
The shoulder is the most mobile joint in the body, as well as the most common site for dislocations. A shoulder dislocation occurs when the top of the upper arm bone (humerus) is pulled away from its normal position in the glenoid, a shallow socket-shaped area on the shoulder blade (scapula). Shoulder dislocations are identified according to the area of the dislocation. Anterior dislocations occur in the front of the shoulder and are by far the most frequent type. Posterior dislocations occur when the bones are separated in the rear portion of the joint.
How Injury Occurs
Falling on an outstretched hand, sustaining a blow to the shoulder and rheumatoid arthritis are commonly associated with shoulder dislocations. The condition can also result from overstretched ligaments (tough bands of tissue that connect bone to bone). Ligaments are very important to the stability of the shoulder and may be damaged by overuse. Sports and occupations that require repeated and prolonged shoulder movements can lead to these kinds of injuries. Some patients have abnormally loose connective tissue that can contribute to shoulder instability even without an injury.
Dislocations cause some pain and swelling in the joint, which may worsen with time. Arm movement will be limited and uncomfortable and the shoulder may pop or make other sounds when moved. You may notice some deformity, especially with an anterior shoulder dislocation. Numbness and tingling may also be felt in the injured arm and hand.
Your doctor will talk with you about your symptoms and the history of the injury. Physical examination of the shoulder will be completed (with anesthesia if needed). X-rays may be ordered to view the joint and rule out any broken bones. If necessary, an MRI (magnetic resonance imaging) will give a more in-depth picture of the shoulder. For serious cases, your doctor may use a special instrument called an arthroscope to look inside the shoulder.
Immediately after the injury, immobilize your arm and shoulder. Apply an ice pack wrapped in a towel to control swelling. See your doctor or go to an emergency room as soon as possible.
Medical treatment involves repositioning the shoulder and controlling pain and swelling. Your doctor may be able to manipulate the joint back into place using a hands-on technique, after which the joint will be X-rayed again to check the position. Pain medications and a muscle relaxant may be given, if needed, to make you more comfortable. Your arm and shoulder will then be placed in a sling for support and to limit shoulder motion.
In severe cases, surgery may be required to secure the shoulder and realign the bones. Overstretched ligaments may also be tightened for greater stability. This is completed under general anesthesia, so you can "sleep" through the procedure. You may be referred for physical and occupational therapy in order to restore normal shoulder function.
Most shoulder dislocations heal with good results. Recovery typically takes between 1 and 3 months and is affected by your age, overall health, the extent of the injury and how well you follow your doctor's instructions. It is important to avoid activities that could cause the shoulder to dislocate again. If surgical treatment is necessary, full recovery may take 6-12 months.
Shoulder dislocations may be associated with torn muscles and ligaments, broken bones and damage to nerves and blood vessels. After one dislocation, you are at higher risk for reoccurrence due to overstretched ligaments.