Post traumatic dislocation of the shoulder joint – this happens after an injury. The ball is forced out of the socket usually with the arm outstretched and forced to the back–the shoulder is forced out the front– this is called an “indirect” force. A direct blow against the shoulder can also cause a dislocation (a “direct” force). During such a shoulder dislocation, the tissues holding the shoulder in place are usually torn. This may either be the separation of the ligaments and labrum (the labrum is the cartilage rim around the socket) referred to as a “Bankart lesion” or even bone being broken off the edge of the socket.
After such a first shoulder dislocation the incidence of repeated dislocations with minimal force is quite high. In younger patients the recurrence rate is higher than in older people. The reason is that in a young person more force is required because of the laxity and strength of the ligaments. That usually leads to the ligaments being stripped off the edge of the socket and this seldom heals again. In older people the ligament is often simply torn and will heal again but it has to be noted that other associated injuries are not uncommon in older persons – this includes fractures, tears of the rotator cuff tendons and injuries to the blood vessels and nerves.
There is a case to be made to repair the tissue after the first shoulder dislocation in a young person, if he or she wants to continue a sporting career. When a recurring dislocation is present the repair of tissues may either be done through a scope (keyhole surgery) by simply repairing the ligaments back to the edge of the socket, or in cases where there has been bone broken off the socket a procedure may have to be done to transfer bone to the damaged area (referred to as a “Latarjet procedure”).