The shoulder joint is a ball and socket joint. It is comprised of the top part of the humerus which is the ball portion. The end of the shoulder blade, called the glenoid, is the socket. This is where the joint articulates. A ball and socket joint mechanically allows for a lot of mobility. An important structure that helps deepen the socket and provide stability to the joint is called the glenoid labrum. The labrum is a ring of cartilage that surrounds the socket which helps prevent dislocation and subluxation of the joint at the extreme ranges of motion.
When there is an injury or a tear to the glenoid labrum, the shoulder joint can become unstable and painful. Labrum injuries can be chronic and fray over time, or acute when there is a specific injury or trauma to the area. We commonly see labral tears in sports that require a lot of overhead or throwing movements like baseball or volleyball. A shoulder dislocation or subluxation can tear the labrum as well, shearing across the labrum as it goes out of the socket. A thorough evaluation by an orthopedist will check for mobility, strength, and instability on exam. MRI arthrogram will typically confirm the diagnosis of a labral tear.
Unfortunately, once the labrum is torn, it does not do a good job of healing itself. Chronic, frayed labral tears can sometimes be treated conservatively with physical therapy or a cortisone injection. Significant labral tears that cause chronic pain, instability, and limitation of activity, often need to be treated surgically. Labral repairs are done arthroscopically in order to re-attach the labrum to the socket. If you experience persistent shoulder pain, it is important to have a thorough evaluation to rule out glenoid labrum damage.