Athletes who repeatedly dislocate the shoulder often have more than one problem going on. Studies show that in the majority of cases, there was more than one problem. And the additional problems weren’t recognized or repaired, leaving the shoulder at risk for failed surgery. The surgeon evaluating patients with shoulder instability wants to provide the best possible results and reduce the risk of failure. That can mean taking time up front (preoperatively) to fully evaluate all of the dynamic structures of the shoulder to identify any and all pathology present.
Bone loss is one of those problems. Without full diagnostic imaging, the surgeon may not see how severe the condition is. If it’s bad enough, open surgery and bone grafting might be necessary. One way to give the shoulder more stability is to deepen the socket. This can be done by adding a rim of bone along the front edge of the glenoid fossa. That will help keep the humeral head in the socket and prevent it from popping out anteriorly (forward direction). Another way to prevent chronic anterior dislocations is to join two tendons together that can resist forward movement of the humerus during motions that can push the head out of the socket.
With repeated dislocations, damage can occur to the head of the humerus. The smooth surface of the humerus hits against the bony edge of the glenoid (socket). The collision causes a dent in the bone of the humerus called a Hill-Sachs lesion. The presence of a Hill-Sachs lesion increases the risk of shoulder redislocation and instability. The defect will have to be filled in either with a bone graft, synthetic plug, or tendon transfer.
Rotator cuff injuries are often missed at the time of diagnosis of the original shoulder instability. One (or more) of the four tendons that make up the rotator cuff (and usually the subscapularis muscle/tendon) may be partially or completely torn. Without the proper pull, support, and coordinated control that the rotator cuff provides, the repaired shoulder can become unstable again. As with the Hill-Sachs bony lesion, this soft tissue lesion can be repaired or reconstructed. The surgeon makes the decision based on all of the factors discussed so far.
And then there’s the management of capsular injuries. The shoulder joint is surrounded by a watertight sac called the joint capsule. The joint capsule holds fluids that lubricate the joint. The walls of the joint capsule are made up of ligaments. Ligaments are connective tissues that attach bones to bones. The joint capsule has a considerable amount of slack, loose tissue, so that the shoulder is unrestricted as it moves through its large range of motion.
The shoulder joint relies on the ability of these ligamentous tissues to hold the shoulder in place. Damage to the capsule or too much laxity from repeated dislocations can contribute to shoulder instability. Surgical repair is possible by harvesting ligamentous tissue from elsewhere and transferring it to the area of capsular deficiency.
This is just a short list of the many factors involved in planning surgical treatment for athletes with chronic shoulder instability. It sounds like you are in good hands. Be patient with the process. Ask whatever questions you may have about tests and procedures. Understanding what the surgeon is looking for and what is found may help you when it comes time to decide about treatment.