Pop Goes the Shoulder: Better Treatments for Dislocations

Surgery to repair problems in the shoulder has changed quite a bit since a newer method called arthroscopy came along. This new procedure lets doctors insert a tiny TV camera right into the shoulder joint, allowing them to see and treat most damage that has occurred inside the joint. Before arthroscopy, doctors had to cut the shoulder joint open to make repairs.

Some people have a shoulder that dislocates repeatedly as a result of a traumatic injury. The shoulder joint forms where the upper arm bone (the humerus) inserts into a socket. With a shoulder dislocation, the top part or “head” of the humerus actually pops out of the socket. The socket is called the glenoid.

Normally there are many surrounding structures to hold the bone in place. Ligaments surround the ball and socket, forming the joint capsule. Along with the joint capsule, muscles and tendons work to keep the head of the humerus in the socket. When an injury causes damage to any of these soft tissues, dislocation can occur.

The round socket has a tough ridge around the edges. This ridge, called the glenoid labrum, deepens the socket, which helps keep the humeral head in place. When the labrum is torn, which commonly happens with a dislocation, the shoulder joint becomes unstable and prone to repeated dislocations.

Surgeons using the arthroscope to repair damage to dislocating shoulders noticed a high rate of dislocation after the operation. This problem has been solved by a group of doctors who discovered a missing link. They studied a group of 42 people with recurring dislocations.

The doctors showed that if the capsule around the joint is still loose or stretched out, it too must be repaired. A new way to tighten the capsule is with a heat treatment called thermal shrinking. This uses radiofrequency energy delivered through a special probe. The doctor is able to view the probe through the arthroscope. The labrum also needs to be repaired if it is torn.

With these changes to the operation, almost everyone (38 out of 42 people) could return to their previous activities. This included sports that require overhead arm motion. Only three people had any further dislocations.

Any injury that tears the ligaments, tendons, or labrum can cause the shoulder to dislocate. For anyone with a shoulder that dislocates over and over, surgery is usually necessary. Using an arthroscope, surgeons can repair damage in the shoulder and reduce the chances of future shoulder dislocation. This includes reattaching the labrum and tightening the capsule.