Shoulder Dislocation / Shoulder Instability

What is a shoulder dislocation?

The shoulder joint is a ball-and-socket joint. It basically looks like a golf ball sitting on a tee. The socket is a part of the shoulder blade (scapula) and called ‘glenoid’. Upper part of the upper arm bone (humerus) forms the ball. This type of joint provides a large range of motion (almost 360°) but also is a rather unstable joint. When the ball leaves the socket it is called ‘dislocation’. When the dislocation is incomplete and the ball quickly reduces into the socket it is called ‘subluxation’.

What is shoulder instability?

The shoulder joint as a ball-and-socket joint is an inherently unstable joint. It’s held in place by anatomical structures such as concavity of the socket, labrum, vacuum, joint capsule and rotator cuff tendons. During a shoulder dislocation, which mostly is caused by a traumatic event, one or more of these structures tears or brakes and can cause recurrent dislocations or subluxations. This is termed as shoulder instability.

Who gets shoulder instability

Most cases of shoulder instability are a consequence of a traumatic dislocation. This commonly happens in contact sports or falls and affects the age group of the 20-35 year old.

A small group of patients with shoulder instability are suffering from a condition ‘generalised ligamentous laxity’ (‘double jointed’). These are presenting with spontaneous shoulder dislocations where no trauma has occurred.

What are the symptoms of shoulder instability?

The most common direction of shoulder dislocation is to the front of the shoulder. After a traumatic dislocation the shoulder often needs to be reduced in an emergency department under sedation. Due to torn structures - most often the ‘labrum’ - the shoulder remains unstable and dislocates easily without any external influence.

In more subtle cases the shoulder causes chronic pain or uncomfortable subluxation events.

How is shoulder instability diagnosed?

Next to the patient’s history, clinical signs during examination will give reason to suggest shoulder instability. Radiographs and MRI or CT scan will confirm the diagnosis.

Treatment of shoulder instability

After shoulder dislocation and reduction the arm should be immobilised for 2 weeks. This is followed by physiotherapy. Depending on the type of dislocation and the damaged structures as well as the age group this treatment might not be able to produce a stable shoulder.

In cases of chronic shoulder instability with recurrent dislocations or subluxations further damage is imminent and a surgical shoulder reconstruction should be performed.

Surgical shoulder reconstruction

Surgical shoulder reconstruction is in most cases performed via arthroscopy (keyhole surgery) aiming to repair damaged anatomical structures such as the labrum. However in select cases an open approach is required. In severe cases or recurrent dislocations after shoulder reconstruction a bone block transfer to the socket (glenoid) is required to achieve a stable shoulder. This procedure is called ‘Bristow-Latarjet-Procedure’.

Preparing for shoulder reconstruction surgery

Prior to the procedure, we will arrange for one preconditioning physiotherapy session where we fit a shoulder immobiliser, explain some simple exercises and give you an ice bladder with icing instructions.

If required we will also arrange for a bulk billed pre-admission clinic at the hospital. This is run by a specialist anaesthetist who will gather information and request investigations that are required for safe anaesthesia.

Our reception staff will advise of costs, hospital and admission details.

Recovery after shoulder reconstruction

Following shoulder reconstruction a shoulder immobiliser has to be worn for 6 week. Physiotherapy will help to maintain a mobile joint and also to increase range of motion once the sling can be discontinued. We will encourage you to enter into a gym based strength and resistance training some 8 to 10 weeks after surgery. Return to contact sports can be expected at 9 to 12 months postoperative. Other non-contact sports can be carried out much earlier.