Symptomatology: Dislocation / Instability

Shoulder dislocations are divided into two categories. You will have either dislocated your shoulder from an injury or from very minimal movement and your shoulder has popped out and gone back into joint fairly rapidly.

Where a dislocation has occurred without an injury, this may indicate that you have a pre-requisite to instability of the shoulder, possibly even in the opposite shoulder and other joints. This may be a sign of generalised joint laxity (hypermobile joints).

For a shoulder dislocation that occurs without injury, surgery is not recommended for this and the best treatment is physiotherapy.

If your shoulder dislocation occurs from an injury and if you go on to have further symptoms then you may require further investigations and potentially surgical treatment. It is a very common injury in contact sports, particularly in rugby and overhead sports such as basketball. Persisting symptoms such as apprehension, symptoms of instability and further dislocation to occur are much more common in patients of a younger age group.

With a traumatic dislocation of the shoulder, it is essential to assess your shoulder and examine for any other signs of any other tendon damage. You will require x-ray, most likely an MR arthrogram (MRI scan with dye injected into the shoulder in order to highlight some of the structures around the socket of the joint) or possibly a CT scan.

Surgery for dislocation involves arthroscopic stabilisation. This is keyhole surgery and involves a hole at the back of the shoulder and two at the front. When the shoulder is forced out the front it tears the lining of the socket. This can be repaired through keyhole surgery using small anchors which are drilled into the edge of the socket, these have sutures (strings within the anchor) which are then passed through the edge of the socket and secured down in order to stabilise the joint. Surgery takes about one hour. The patient can go home the same day and the arm is rested in a sling for two weeks. Recovery can take from three to four months. Average return to sport, particularly contact sports is about three to four months. The risk of re-dislocation is still higher than the average population and the younger you are the higher this is. Current studies show that there is a 6% re-dislocation rate with arthroscopic techniques at two to five years.

The other risks with this surgery include infection, pain, stiffness, bleeding and nerve injury. There is a small risk of some permanent stiffness. This may manifest itself by slightly reduced external rotation (turning the arm out to the side) and elevating the arm up above the head with the elbow flexed. Physiotherapy can improve this but it is not uncommon to have some degree of permanent stiffness.

If your investigations show that there is bone loss on the socket or at the back of the humeral head (ball joint) then more extensive open surgery may be indicated. If the shoulder has dislocated on a number of occasions, as the ball part slides over the front of the socket this may scuff the edge of the socket and obviously the surface area is reduced. If this is the case then open surgery may be required in the form of bone grafting (a modified Laterjet procedure). This involves an incision on the front of the shoulder and bone is taken from the edge of the scapula or from the edge of your pelvis and fixed with two screws onto the front edge of the socket, the surrounding soft tissues of the capsule are then secured and tightened as well. The rehabilitation and recovery is essentially the same as for arthroscopic surgery but with open surgery there are risks of the bone graft and metalwork in the shoulder.

Further Reading