What is shoulder instability?
“Shoulder instability” is a term used for a spectrum of shoulder disorders including
complete dislocation, subluxation or laxity. A dislocated shoulder occurs when the
shoulder comes completely out of joint. When the shoulder slips only partially out,
this is subluxation. Laxity is a variation of normal where some people have looser
joints than others. While laxity is normal, instability is not.
What are types of shoulder instability?
Most physicians categorize instability by direction. Anterior dislocations, or when the shoulder comes out the front, are by far the most common. Posterior dislocations (towards the back of the body) are more rare, but may also occur. Multidirectional instability is where the shoulder is unstable in anterior, posterior and inferior directions. It is important to distinguish the different types, as the treatment options vary greatly.
What causes shoulder instability?
The capsule and ligaments keep the shoulder in the joint and functioning well.
Generally, its takes a significant amount of force to allow the shoulder to dislocate,
like a football tackle or falling with your arm stretched out overhead. If the shoulder
slips in and out multiple times, it is considered “unstable”. Instability, especially
anterior, can make it difficult to return to sporting activities, particularly overhead
athletes like in baseball or volleyball. Contact athletes (i.e rubgy, football players)
have a higher rate of recurrent dislocation or subluxation.
Select from the topics below
to learn more about shoulder injuries,
disorders and treatment options
What are the symptoms of shoulder instability?
A frank dislocation of the shoulder is usually obvious. You may have a visible deformity with swelling and pain. You will also be unable to move your shoulder and may have mild numbness or tingling in the arm with muscle spasms. Sometimes the shoulder “pops back in” on its own, but most of the time it will have to be put back in the joint in the emergency room. The emergency room will obtain X-rays, but you will probably need further imaging with an MRI.
What is a labrum tear or "cartilage tear" of the shoulder?
The labrum is a fibrocartilage ring that attaches to the rim of the glenoid or shoulder socket. A common type of labrum tear is a “SLAP” tear, which stands for Superior Labrum Anterior Posterior. The SLAP tear occurs at the top portion of the labrum where the biceps tendon attaches. Usually it occurs from a fall on an outstretched arm or dislocation. From a dislocation, the front part of the labrum can tear, ("Bankart tear") as well. You may feel a popping or clicking sensation in the shoulder, and your shoulder may be unstable or painful with certain motions. Treatment depends on your age and the extent of your injury.
How do you treat shoulder instability?
The treatment of shoulder instability depends on a number of factors, including age, hand-dominance, preferred sport and the extent of injury. Physical therapy may help strengthen the surrounding musculature and keep the shoulder reduced. People with multidirectional instability benefit the most from physical therapy. Cortisone injections are usually not recommended.
Do I need surgery?
Anyone who has recurrent instability or continued feelings of their shoulder “slipping” out of socket, even after a rehabilitation program, would likely benefit from surgery. Certain people, depending on their age and activity level, may require a surgical intervention in order to maintain the integrity of their shoulder and allow return to sporting activities. Surgery is generally performed arthroscopically, but more complex injuries are better treated with open surgery. Surgery is aimed at repairing the labrum and tightening the ligaments and capsule of the shoulder in order to restore normal mechanics and keep the shoulder stable.