The shoulder has given up stability for mobility. It is the only joint in the body that can turn 360 degrees. Because of this mobility we often see instability, meaning the ball jumps in and out of the socket joint.
The ball is kept stable in the socket due to ligaments around the ball and socket (glenohumeral) and a cartilage rim that deepens the socket joint – called the labrum.
Different types of instabilities occur.
The first one is without any trauma and usually is a multi-directional instability. This is where the ligaments of an individual are more lax and it causes subluxation of the ball and socket joint.
A subluxation is where the joint moves more than it should without popping out completely.
This is usually not painful and physiotherapy is indicated to strengthen the muscles around the shoulder joint.
A dislocation due to trauma is where a big enough force has gone through the shoulder to force the ball out of the socket. The shoulder can dislocate to the back, the front and to the bottom of the joint. Most of the time the
patient has to go to an emergency department to have it reduced.
Once the shoulder has dislocated there are certain patterns of damage one can sustain. These are the following:
A Bankart lesion is where the labrum (cartilage rim) is torn from the glenoid (socket )
A bony Bankart lesion is where a piece of bone has broken off the glenoid and causes the glenoid to become narrower. The humeral head can then easily slip out of the socket.
A Hill-Sacks lesion is an indentation in the humeral head (ball) where it has slipped over the rim of the glenoid.
Other types of injuries:
ALPSA : anterior labral periosteal sleeve avulsion.
HAGL: Humeral avulsion of the glenohumeral ligament.
The treatment of shoulder dislocations depends on the patient’s profile. In other words the age of the patient, the type of sport he or she does and at what level they participate.
The surgery done to stabilize the joint would be arthroscopic or open surgery. The decision is made by taking in account the patient’s profile and the type of injury the patient has. Your surgeon will discuss this with you.