Dislocations of the shoulder joint are common in sports involving contact elements such as cricket football, kabaddi, Rugby, and football. They also occur frequently from falls, usually onto an outstretched arm. This results in the most common form of shoulder dislocations, an anterior dislocation, which make up to 95% of all dislocations.
Dislocations can also be
- Superior or
The reason shoulder dislocations are so common is that shoulder is highly mobile joint. The shoulder has the largest range of motion of any joint in the body, but the congruency of the articulating bones (humerus and scapula) is very poor. The joint therefore relies on the support of the surrounding soft tissues - the joint capsule, labrum, ligaments and muscles.
IN SHOULDER DISLOCATION, The most common damage is to the glenoid labrum. This is a ring of cartilage surrounding the socket of the joint (part of the scapula or shoulder blade) which acts to increase the congruency of the joint by effectively deepening the socket. Damage to other soft tissues such as rotator cuff tendons, nerves and blood vessels can occur. Usually, an X-ray is done before the shoulder is reduced to check for any associated damage. After this, depending on the direction of dislocation, a manoeuvre will be performed to allow the humerus to move back into position. The arm is immobilised in a sling for 3 weeks.
After a dislocation the chances of the same shoulder dislocating again are higher. This is due to laxity in the joint capsule and ligaments surrounding the joint after they were stretched during the first injury. Any associated injuries also make repeat dislocations more likely. In order to prevent recurrent dislocations, a period of extensive rehabilitation is required. This is aimed at strengthening the muscles surrounding the shoulder joint, improve proprioception (the sense of the joints position), and restore full range of motion.
It is helpful to know the basics of shoulder anatomy in order to understand how these injuries occur. The shoulder complex is made up of three bones: the scapula (shoulder blade), clavicle (collar bone), and humerus (arm bone). The actual shoulder joint is where the scapula and humerus meet and is surrounded by various ligaments, which hold the bones together and limit excessive movement. Overlying this are the muscles, specifically the rotator cuff muscles that surround the joint and stabilize the humerus into the shoulder socket during active use of the arm.
When the shoulder dislocates, the ligaments in the front of the shoulder i.e. labrum gets torn. this is callesbankart lesion. impression on humeral head is called hill sachlesion. Although the ligaments may heal, the result is a shoulder that has even more laxity and instability than prior to the injury. Many athletes and active individuals will experience multiple occurrences of dislocation after the first event due to the increasingly unstable shoulder. /Successive dislocations, because of the increased amount of instability in the joint, often take significantly less force to occur. Whereas the first dislocation is usually the result of a traumatic force upon the shoulder, subsequent dislocations could result from ordinary, athletic or heavy use of the arm. Athletes may experience 2nd and 3rd dislocations with the act of throwing a ball or quickly raising the arm for a jump shot.
Another common condition that may exist with shoulder dislocation is a SLAP tear, which is a tear to a structure in the shoulder known as the glenoid labrum at specific region. SLAP stands for superior labral anterior posterior. Because these cartilaginous structures do not have a great blood supply, they often do not heal on their own and may require surgical intervention to re-attach the labrum to the bone.
Treatment for shoulder dislocation
Closed reduction with traction---methods
Treatment for recurrent dislocation
Arthroscopic bankart repair(labral tear repair)
This is a process of reattaching labrum to bony margin with the help of special anchor sutures. This is done arthroscopically with keyhole surgey. There are no stitches left after surgery. Success rate for this surgery is more than 95%.
- Latarjetprocedure- Attachment of coracoid process to anterior glenoid
- Indication- bony bankart with koss of bone more than 20% from glenoid
- Failure of arthroscopic surgery
- Success rate- more than 99%