The shoulder is a ball and socket joint. Shoulder instability (or shoulder dislocation) occurs when the humerus (or ball part of the shoulder) is forced out of the socket (glenoid), most commonly anteriorly. This is typically the result of trauma but can occur due to repetitive overuse in sports such as baseball or swimming. Partial or complete dislocations can result in pain and decreased function in the shoulder.
- Most patients should try a period of non-operative treatment after a shoulder dislocation. Particularly after traumatic dislocations, the shoulder needs to be reduced (or “put back in place”) in the ER. During the first few weeks, the arm is kept in a sling to allow the swelling to decrease and the pain to lessen.
- Physical therapists will first focus on decreasing inflammation and pain by using ice, heat and other modalities. Eventually, increasing range of motion and strengthening exercises are instituted.
- If the dislocation happens in an athlete, they can typically return to their sport once they have full, pain-free range of motion and normal strength. This may take anywhere from a few weeks to a few months.
Certain patients are at increased risk of future instability episodes, which makes them candidates to consider earlier surgical intervention. Younger patients under the age of 20 and those who play contact sports are at a significantly higher risk of their shoulder dislocating again. Why is this important? Well, each dislocation is not a benign event… pathology can worsen. In many cases, as the pathology and ligament tears get worse, arthroscopic surgery may not be enough to provide a predictably successful outcome.
As a refresher, arthroscopic surgery involves making poke holes in the skin and operating with a camera and special tools that fit through the poke holes. This technique has become the gold standard for treating most cases of instability.
When the shoulder dislocates, usually the labrum tears. The labrum is a cartilaginous structure that goes around the socket (or glenoid) like a bumper on a pool table. Attached to the labrum are the ligaments that help provide stability to the shoulder. To surgically fix someone who dislocates their shoulder, the labrum and ligaments need to be repaired by placing plastic anchors through the poke holes in the skin into the glenoid. These anchors have sutures attached to them that are used to sew the labrum back to the glenoid.
Every time the shoulder dislocates, one runs the risk of injuring the shoulder more… particularly the bone on the ball and/or socket. Sometimes the bone of the socket breaks off acutely; other times, it is a progressive process whereby each time the shoulder pops out of place the bone erodes away. In either case, if too much bone is compromised or missing, doing a standard arthroscopic repair has a much lower success rate. In these cases, an open procedure is required. There are several different open procedures that are used. In cases of bone loss, the surgeon will likely use what is referred to as a Latarjet procedure. In these cases, a piece of bone is taken from the patient’s coracoid (a bone in the front of the shoulder) and moved and secured to the front of the glenoid.
Another situation which may necessitate an open procedure is when the labrum and capsule quality are not good. This poor quality can be either identified on a preoperative MRI, or assessed by a surgeon via arthroscopy. When there is concern about ligament quality, an incision is made in the front of the shoulder and the capsule can be plicated or tightened and secured with sutures. Alternatively, a bone block procedure can be used in these cases as well.
If you dislocate your shoulder, after having it reduced in the ER, make sure to follow up with an orthopedic surgeon to assess your risk for future instability episodes which will help guide the appropriate treatment.
Dr. Joshua Dines is an orthopedic surgeon and a member of the HSS Sports Medicine Institute. He currently serves as an assistant team physician for the New York Mets.
