The labrum is a fibrocartilage rim which is attached around the margin of the glenoid cavity (the shoulder socket). The shoulder socket is very shallow, which allows a healthy shoulder to move through a wide range of motion. The labrum deepens the shallow socket and helps maintain shoulder joint stability. When the labrum sustains a significant tear, the shoulder becomes unstable and can dislocate or sublux repeatedly. Subluxation refers to a partial dislocation - when the ball comes partway out of the socket and then back in. A labral tear can be caused by repetitive activities and get progressively worse over time or can happen suddenly by falling on an outstretched arm or sustaining a dislocation injury. A SLAP lesion (Superior Labrum Anterior to Posterior) refers to a tear in the labrum that runs across the top of the labrum from front to back. Shoulder instability and recurrent subluxation are not always related to injury or repetitive use. They can also be caused by general ligament laxity (looseness), in which case it can be referred to as multidirectional instability.
When you come to see the doctor with shoulder instability, the doctor will examine the shoulder and assess your ligaments for signs of laxity. An MRI may be ordered to assess the shoulder for tears of the muscles, ligaments, or labrum.
An unstable shoulder in your 40’s or 50’s is typically treated conservatively initially. Non-surgical treatment options include physical therapy, activity modification (avoiding activities that aggravate your symptoms), and use of anti-inflammatory medication. Physical therapy for shoulder instability focuses on strengthening and stabilization exercises for the muscles around the shoulder and shoulder blade. If conservative treatment fails to stabilize the shoulder joint and improve symptoms, surgery may be recommended. An unstable shoulder in your 20’s has higher risk of repeat dislocation and may not be appropriate for conservative treatment.
If the shoulder was dislocated traumatically and a SLAP lesion is present, the surgical repair is referred to as a SLAP lesion repair and involves use of sutures to reattach the torn labrum to the bone of the shoulder socket. In exchange for significant improvement in joint stability, it is common to lose a bit of rotational range of motion.
Post-operatively, the doctor will require use of a sling for 6 weeks along with rehab provided by a physical or occupational therapist. Rehab begins with passive range of motion and progresses to active exercises after 6 weeks and to strengthening about 10 weeks after surgery. The patient is typically released to return to work 14 weeks after surgery, but this can be pushed back by a month to allow for higher level strengthening exercises if the job involves manual labor.