Shoulder instability is a dislocation or subluxation of the glenohumeral joint. This joint is inherently unstable and the most commonly dislocated joint in the body and relies on the labrum, ligaments and tendons for its stability.

Dislocations can be traumatic or atraumatic. Traumatic dislocations are the commonest and usually occur following a significant injury, whereby the humerus moves out of the socket (most commonly from the front). The labrum and the ligaments are torn in the process. This is common in young people. Once a young person sustains a traumatic dislocation, they are at a very high risk of developing recurrent dislocations. Traumatic dislocations in the elderly often result in rotator cuff tears and the risk of recurrent dislocations is low.

Atraumatic dislocations occur without an injury and are often the result of hypermobility due to loose/lax ligaments or as a result of muscle imbalance. These dislocations are commonly multidirectional.

The priority with a dislocated shoulder is to reduce the dislocation as soon as possible. Traumatic dislocations often require sedation in A&E and reduction by doctors. Patients with recurrent and atraumatic dislocations can often reduce the dislocation themselves.

It is important to keep the shoulder muscles strong together with proprioceptive exercises to stabilise the shoulder. Physiotherapy plays a large role in the treatment of these patients.

Once traumatic dislocations become recurrent, surgery will be required to stabilise the joint. Surgery can be performed in the form of a key hole surgery- shoulder arthroscopy with repair of the labrum.