Shoulder Dislocation – Part Two

The conservative treatment of dislocations of the shoulder is a controversial matter in orthopaedics, with management in a sling for anything from one to six weeks. An immobilising strap may be applied around the waist but this is not universal. The arm is kept in to the side with the forearm across the abdomen (officially internal rotation and adduction) to prevent stresses to the injured areas, avoiding arm away from the body and moving it outwards (officially external rotation and abduction).

Scientific work has given a better indication of how or why these problems should be immobilised. An MRI scanning study indicated that the shoulder socket and the rim, made of fibrocartilage, are kept in the closest correct relationship by having the arm by the side and laterally rotated 35 degrees. Another study on cadavers showed that if the arm was kept in slight adduction there was a reasonable range of motion during which the two vital structures maintained close alignment. Allowing the arm to flex forward or to abduct outwards was disruptive for the rim or labrum of the socket.

How long a person should be in a sling is not clear and wearing a sling for three to four weeks is common in younger people with perhaps a bit shorter for older patients. One study indicated that the chances of the shoulder dislocating again was reduced by having a longer period of immobilisation. However, another long study following patients over 10 years did not find any effect on the recurrence rate by the period they were immobilised. At the three or four week point the patient is usually reviewed by a physiotherapist and rehabilitation started.

Rehabilitation starts with pendular exercises which allow range of motion of the shoulder joint without high levels of stress through the area. The patient bends at the waist and permits the arm to hang vertically, making movement easy. Physiotherapists will teach scapular movements to maintain range of this area and progress the patient towards active assisted exercises next. Muscle function and range of movement can be facilitated by using the unaffected arm to participate, thereby allowing increased but controlled forces to be applied.

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.

Stronger rehabilitation can be pursued if the patient needs high performance from their shoulder but four months should typically elapse before overhead sports practise will be wise. Older patients or those with greater tuberosity fractures (a bit of the upper arm bone where tendons attach) have a somewhat better prognosis. Modification of a patient’s typical activities may be required by limiting arduous work, controlling overhead activities and deciding not to indulge in sporting activities which carry increased risks.

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.

When a problem shoulder should be surgically managed is not generally agreed but surgery early after the dislocation may be helpful. Scientific studies vary but in one there was only a four percent re-dislocation after arthroscopic shoulder stabilisation compared to a 94 percent re-dislocation rate in those managed non-operatively. Conservative treatment may have higher recurrence rates than those managed surgically. Open surgery used to provide better stability results but newer techniques with the arthroscope have meant that this technique is now as good.

Jonathan Blood Smyth is the Superintendent of Physiotherapists at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for physiotherapists in Bolton visit his website.