Shoulder joint is the most mobile joint of the body, because of which it is possible to bring your hand all over. The down side of this well desired mobility is that it is prone to dislocation. First episode of dislocation occurs, usually as a result of trauma such as fall on an out-stretched hand. As the shoulder dislocates, it tears away the tissues controlling it. After it is repositioned, the tissues heal up. In some cases, this healing does not happen, and such cases have a tendency to dislocate again and again. In some other cases, the tendency to recur is as a result of some manufacturing defect in the body such as loose jointedness. Once the shoulder starts dislocating again and again, the only treatment is to fix it surgically.
Surgery for recurrent dislocation has been in vogue for hundreds of years. It used to be done by open surgery, which lead to scarring and limitation of shoulder movements. This has been now replaced with arthroscopic surgery (key-hole surgery), where the re-fixation of the torn tissue is done via three key holes, without cutting open the joint. Special fixation devices called anchors are used to re-fix the tissues to the bone. The advantage of this method is that there is minimum pain, quick recovery, and no loss of flexibility.
Shown below are the shoulders of two patients, one operated by open surgery and the other by arthroscopic surgery.