What can cause shoulder instability?

Shoulder instability is a common orthopaedic problem that can result in pain, limited movement and reduced sense of balance in the shoulder.

Here to provide an expert insight into shoulder instability, including causes, diagnosis and surgical treatment, is Mr Phil Wright, renowned consultant orthopaedic surgeon based in Leeds and Bradford.

What is shoulder instability, and what are the common causes and risk factors associated with this condition?

Shoulder instability is normally used to refer to instability of the ball and socket joint. It often presents as:

• A feeling that the shoulder is coming out of joint
• A feeling that the shoulder is going to move in an abnormal direction
• A feeling that the shoulder won’t be able to carry out and support certain movements

In most patients, shoulder instability is caused by an injury, where the ligaments (sometimes in combination with the bone) are damaged as a result of severe force applied across the shoulder. A typical example of this would be somebody who plays contact sports, for example a rugby player who is tackled awkwardly. This movement causes the shoulder to be forced out of joint, damaging bones and ligaments in the same process.

A less common type of shoulder instability is atraumatic, sometimes referred to as muscle patterning instability or hypermobility, which usually occurs without any injury or traumatic event. This type of instability is more common in younger people and in women, because they tend to have looser, more subtle joints and ligaments. Atraumatic shoulder instability can be more difficult to treat, and for most patients, the mainstay of treatment is physiotherapy rather than any surgical intervention.

How do you diagnose and differentiate between the types of shoulder instability?

For most patients, it is very straightforward to determine the type of shoulder instability that they have, because they will come to hospital with a history of a significant injury where:

1. The shoulder becomes painful
2. The patient is aware of a deformity
3. The patient goes to the A&E department, where an x-ray demonstrates that the shoulder is out of joint
4. A member of staff in the A&E department puts the shoulder back into joint with sedation or pain relief medication

Patients with the atraumatic type of instability won't describe a traumatic event. Instead, patients will be aware of a gradual process whereby: their shoulder doesn’t come out of joint; their shoulder stays stuck out of joint; or their shoulder clunks, clicks or does strange things when it is moved unpredictably in certain directions and/or positions.

X-rays are generally helpful in assessing shoulder instability, because they provide information about the shape of the ball and socket joint, and can also guide treatment for a patient who had a traumatic event leading to instability. My personal preference is to perform MRI scans of the shoulder as well, with dye injected inside, because this provides the greatest detail about the ligaments and the attachments of the ligaments to the socket. It is often these that are addressed when a patient undergoes surgery to stabilise their shoulder.

What surgical procedures are commonly performed for shoulder instability?

Most patients who undergo surgery for shoulder instability have the traumatic type of shoulder instability. The majority of these patients can be treated with a keyhole operation that repairs the ligaments back to the sockets where they have become detached (which is sometimes called a labral repair). During surgery, small instruments are passed through keyholes into the shoulder in order to immobilise the tissue. Small device plugs with stitches (called bone anchors) attached to them are then inserted into the socket. The suits are passed through the tissue, and lastly, the knots are tied to secure the tissue back down to the bone.

As well as this, some patients who have the more severe types of traumatic shoulder instability can lose bone from the socket, and sometimes, from the ball as well. These patients tend to have higher rates of ongoing instability with keyhole repairs, and thus, I perform a more traditional procedure through a small incision at the front of the shoulder for these patients, where the bone is moved from one area of the shoulder to the front of the socket. This is done to effectively widen and build up the socket, so that the socket is more able to hold onto the ball and so that the shoulder is less likely to come out of joint in certain positions.

What is the expected recovery process following surgical treatment for shoulder instability?

After surgery, patients typically wear a sling for around four weeks. This can cause the shoulder to stiffen to some degree, but this isn't necessarily a bad thing in the early stages of recovery.

After the sling is removed, the patient sees a physiotherapist to follow a programme of rehabilitation which is aimed at restoring movement and returning the sense of balance to the shoulder, as well as building up the muscles around the shoulder. These muscles play an important part in maintaining a stable shoulder through a full range of movement.

Different patients tend to recover at different rates. However, often, a patient’s recovery will be determined by what their level of activity was before surgery. I'm personally very keen that my patients see a physiotherapist before surgery for what is known as “prehabilitation” because starting their physio program in advance of their surgical procedure can give them a head start on their recovery and provide a faster return to their pre-injury level of activity - whether that is sports, employment, or just day-to-day activities.

Mr Phil Wright is a leading consultant orthopaedic surgeon with over 25 years’ experience who specialises in surgery of the shoulder and elbow.

If you require surgical treatment for shoulder instability and you would like to consult your options with an expert, don’t hesitate to book an appointment with Mr Wright via his Top Doctors profile today.