What Happens When a Shoulder Dislocates?
Shoulder dislocations are one of the most common shoulder injuries seen in our work hard, play harder environment. The shoulder joint (glenohumeral joint) is comprised of the glenoid (socket) and humeral head (ball). This joint is often compared to a golf ball on a golf tee due to the bony socket being very shallow. Because of the shoulder’s shallow bone socket, we are very reliant on our shoulder ligaments to hold the ball in the socket.
First time shoulder dislocations frequently occur during a high energy fall, such as a skiing or mountain biking accident. In most cases, the ball (humeral head) tends to dislocate off the front of the shoulder socket (anterior dislocation). The labrum, which is like a rubber gasket that attaches circumferentially around the edge of the socket, commonly tears away from the socket during a dislocation. Unfortunately, the labrum does not heal back in the correct position after a dislocation and for this reason, young, active people are more likely to continue to dislocate their shoulder after dislocating it for the first time.
When the shoulder first dislocates, it is common for the labrum to tear and the shoulder ligaments to stretch. However, as more dislocations occur over time, more significant damage is done to the shoulder. Often, patients begin with a simple labral tear, but after continuing to dislocate their shoulder, they further tear the ligaments and patients can chip away or just wear down the bony edge of the shoulder socket. This bone loss makes patient’s shoulders even more unstable just like a chip in a golf tee allows for a golf ball to fall off more easily. Given this, young people with recurrent shoulder instability often come to surgery to stabilize the shoulder.