OVERVIEW

Shoulder dislocations occur when the upper arm bone (humerus) shifts out of the cup-shaped socket (glenoid) in the shoulder blade. The shoulder joint is highly mobile but is also susceptible to instability, making it prone to dislocations.

Types of shoulder dislocations

There are different types of shoulder dislocations, classified based on the direction of the dislocation:

1. Anterior shoulder dislocation: This is the most common type, where the humerus is displaced forward out of the socket.
2. Posterior shoulder dislocation: The humerus is pushed backwards out of the socket, often caused by forceful muscle contractions or trauma.
3. Inferior shoulder dislocation (luxatio erecta): The humerus dislocates downward, an uncommon but severe form of shoulder dislocation.
4. Multidirectional instability: This occurs when the shoulder dislocates in multiple directions, indicating generalised instability of the joint.

Causes of shoulder dislocations

Several factors contribute to shoulder dislocations:

1. Trauma: High-impact events such as falls, sports injuries, or accidents can force the shoulder out of its socket.
2. Repetitive strain: Overuse or repetitive motion, common in certain sports or occupational activities, can lead to shoulder instability and dislocations.
3. Anatomical factors: Some individuals may have naturally loose ligaments or a shallow shoulder socket, increasing the risk of dislocations.