Shoulder instability (dislocation)

How does a shoulder dislocate?

The shoulder joint is made up of three bones: the shoulder blade, the collar bone, in the upper arm bone called the humerus.  The head of the humerus rests in a shallow socket in the shoulder blade called the glenoid.  The humeral head is usually much larger than the glenoid so a soft fibrous tissue rim called the labrum surrounds the socket to help stabilize the joint.  This fibrous rim deepens the socket by up to 50% so that the head of the humerus fits better.

When a significant amount of force is applied to the shoulder joint, the labrum can tear off of the socket, which allows the humeral head to dislocate from the socket.

Why did my shoulder dislocate?

Injuries to the labrum can occur from acute trauma or repetitive shoulder motion.  People that are prone to a shoulder dislocation are patients that are young, perform overhead activities, or are involved in high impact activities.  Although most patients that suffer a shoulder dislocation are young, I see shoulder dislocations in patients of all ages.

What are the symptoms of a shoulder dislocation?

Most patients feel a pop in their shoulder and severe pain when suffering a shoulder dislocation.  They may also notice that their shoulder looks different than the other side.  Sometimes, a shoulder will dislocate, but then returned to the socket on its own.  Most times, however, the shoulder will not return to the socket on its own.  In these cases, patients have to have the shoulder put back in the socket by a physician in the emergency room.

In some individuals, a shoulder dislocation can be associated with a rotator cuff tear.  The symptoms of a rotator cuff tear are usually pain and weakness in the shoulder.  Read more about rotator cuff tears here.

How do you diagnose a labral tear?

A labral tear is normally diagnosed with a combination of your medical history, a physical exam by a shoulder specialist, and imaging.  I will perform special tests to determine if your shoulder has abnormal motion, indicating a labral tear.  On occasion, an MRI of the shoulder is needed to determine the location of the tear for surgical planning.

How is a labral tear treated?

Prior to recommending treatment for a labral tear, I will have a long discussion with you about your desired outcome and desired activities after your injury.  After a first-time dislocation, most patients can be treated without surgery.  Unfortunately, however, in young patients, another dislocation can occur in up to 80% of patients.  This is usually due to labrum healing on the socket in an abnormal position.  If another dislocation occurs, or you desire a return to active sports, we may discuss minimally invasive, arthroscopic surgery to fix the labral tear.

An arthroscopic labral repair involves stitching the torn labrum back onto the socket.  This procedure is performed on an outpatient basis by shoulder specialists.

What is the recovery time after an arthroscopic labral repair?

Patients are first placed in a sling after surgery for approximately 4 weeks.  After four weeks, I normally begin home exercises and physical therapy to work on shoulder range-of-motion.  I allowed strength training at about three months from surgery.  Patients can return to their normal activities once they regain full-strength of their shoulder, normally 4 to 6 months after surgery.