Shoulder Joint Dislocation - Part Two

The management of dislocated shoulders is a matter of controversy in the orthopaedic field, with the usual management being confined to a sling for between one and six weeks, with or without a strap around the waist to prevent external rotation. The arm is maintained close to the body with the forearm across the belly, a position known as medial rotation and adduction. This avoids the stresses which would be applied to the joint if it were moved to the side or outwards, known as lateral rotation and abduction.

Recent scientific studies have given new ideas on why these injuries should be immobilised in particular ways. One study done via MRI scanning showed that the socket and the fibro-cartilage rim, which is often damaged, were kept in most intimate contact with the arm by the side and the shoulder externally rotated at thirty-five degrees. A second study performed with dead bodies showed a reasonable range of movement where the two important structures are closely applied if the arm is in slight adduction. Bringing the arm forwards (flexion) or out sideways (abduction) tended to disrupt the joint rim.

The time of immobilisation is not one of general agreement with three or four weeks in a sling typically prescribed for younger people and shorter periods for older people. A longer period of immobilisation was shown in one study to significantly lower the rates of recurrent dislocation. Another study followed patient with shoulder dislocation for ten years and found no influence of the period of immobilisation on the rate of recurrent dislocation. After the patient is reviewed at the three week period they start their rehabilitation with the physiotherapists.

Pendular exercises begin rehabilitation and due to the patient bending over and the arm hanging dependent there is less force through the shoulder, allowing the maintenance of shoulder range without inappropriate joint stresses on the capsule. Early practising of scapular movements is also taught to maintain shoulder girdle mobility and function. The physiotherapist will then progress the patient onto active assisted exercises which promote range of movement and muscle activity with the unaffected arm providing significant effort to reduce the stresses through the injured side.

External rotation will initially be limited due to the re-dislocation risk and gradually allowed to increase as the weeks go on, but it is never pushed strongly and there may be an advantage to the patient if they lose some range of this movement. This may protect them from easily going into the risky and vulnerable dislocating position again. At six weeks much of the soft tissue healing will be well advanced and patients can start doing full active range of movement and strengthening exercises for the shoulder and shoulder girdle.

More vigorous rehabilitation can follow if the patient has particular requirements for their shoulder function, but overhead sports are unlikely to be sensible for at least four months. If the patient is older or the greater tuberosity, a part of the humeral head which bears muscular insertions, is fractured then the prognosis is better overall. In some cases the person may have to modify their activity to avoid the risk of dislocating again, limiting overhead work, avoiding high risk sporting activities and modifying heavy work.

Recurrence of dislocation is 30% overall for non-athletic individuals and 82% in those who are athletes, if they are not surgically managed. However, re-dislocation rates after the first dislocation event vary greatly depending on the age of the individual. Very young people, under ten years old, have a 100% likelihood of dislocating again whilst people between 41 and 50 years old have a probability of recurrence between 0 and 24%. If patients suffer from recurrent dislocation or subluxation (partial dislocation) they may need surgical management.

The surgical management of dislocated shoulder is not wholly clear but some indications are that early surgery may be a helpful technique. There is variation amongst scientific papers but one showed a 94 percent re-dislocation after conservative management and only a 4 percent recurrence after stabilisation of the shoulder with arthroscopic surgery. Overall there may be higher rates of recurrence in conservatively managed patients. Surgical results were better with open surgery but advances in arthroscopic technique have brought this up to the same level.

About the Author

Jonathan Blood Smyth, editor of the Physiotherapy Site, writes articles about Physiotherapist, back pain, orthopaedic conditions, neck pain, injury management and physiotherapist in hartlepool. Jonathan is a superintendant physiotherapist at an NHS hospital in the South-West of the UK.