The Dislocated Shoulder
When we talk about a dislocated shoulder we are talking about a dislocation of the gleno-humeral joint or the ball and socket joint of the shoulder complex. It is important to make this clear as it is possible to dislocate other joints in the shoulder too. It is, however, dislocation of this joint that is the most common and troublesome.
A dislocated shoulder tends to occur as a result of trauma of some kind that forces the ball out of its shallow socket. The tendency is for the ball or humeral head to be forced forwards so that it sits in front of the socket. This is known as an anterior dislocation.
It is commonly caused by a stress on the arm forcing it into a position known as extension and lateral rotation. In simple terms the arm is forced backwards, often with the elbow bent. The forceful movement makes the arm act like a lever forcing the end (the ball) out of its socket.
The muscles helping to hold the ball in place tend to be more lax at the front of the shoulder therefore making it easier for the joint to become dislocated.
Once you have a dislocated shoulder there exists significantly higher chance of future dislocations as the muscles or capsule at the front of the shoulder joint will tend to remain stretched and do not function effectively to help keep the ball in its socket. Repeated dislocations are a common story. So much so that people are frequently able to dislocate their shoulders at will as a 'party trick.'
Here then are the essentials of a dislocated shoulder.
The pain from a dislocated shoulder can be extremely severe. When it occurs there are three basic outcomes:
The joint remains dislocated.
It is important to get the joint relocated as soon as possible. This can be done without anaesthetic but this is not always possible as there is often a great deal of pain and protective muscle spasm around the shoulder. The patient would be kept warm, not given food or drink and taken to an emergency unit immediately.
There will normally be an attempt at relocation of the joint without general anaesthetic first. If unsuccessful 'a minor whif' of a general anaesthetic normally allows the joint to be relocated easily.
The joint is subluxed
Subluxed describes the situation where the ball is sitting half in and half out of the socket or on the edge, if you like. In such scenarios relocation is normally much easier and often happens spontaneously. It may, however, require intervention as that for a complete dislocation. Subluxation is not always as easy to diagnose as the previous situation as there is less of a deformity apparent.
It is important to note that this situation is different from a 'chronic subluxation' that exists essentially permanently when the muscles around the joint no longer hold the head of the humerus (ball) in its socket. This can be due to repeated dislocations or seen following a stroke that results in low tone of the shoulder muscles.
The joint has relocated
This is the best of the three outcomes as there is less likelihood of any major intervention. It is however necessary to test, as in the previous scenarios, for nerve damage around the shoulder. The patient may initially be unaware that their shoulder has dislocated.
COMPLICATIONS OF SHOULDER DISLOCATION
* The dislocating head of the humerus as it is forced out can damage the cartilage rim of the socket and possibly cause it to become detached. This causes added instability to the joint and will normally require surgery to repair the damage, once the initial injury has settled.
* The trauma of the dislocation can also damage the head of the humerus itself resulting in a fracture. This scenario is called a fracture dislocation and can be classed as a relatively serious injury. The fracture may be a small avulsion where a fragment of bone is chipped off or a more serious break in the bone requiring surgical intervention.
* Another complication of both dislocation and relocation is damage to one of the nerves that passes around the shoulder. Loss of, or altered sensation in the skin over the shoulder region is a sign that the nerve has been affected. A professional medical opinion is necessary in such cases. For more detailed information on nerve injuries please see our nerve injury page
TREATMENT AND REHABILITATION OF A DISLOCATED SHOULDER
First and foremost treat the injury as serious and get immediate medical attention when it occurs. Keep the casualty warm and comfortable. The arm is best supported with the elbow bent to ninety degrees in a sling. You may find that the casualty prefers to support the arm themselves with the unaffected limb rather than have a sling applied.
Following this you will be given advice as to the correct course of action by the doctor. This normally consists (if no surgery is required) of a period of immobilisation or rest, commonly in a sling. This used to be for six weeks or more as it was believed that this period of time allowed the muscles around the shoulder to tighten up.
There is however no compelling evidence that this prolonged rest period achieves this. The current thinking is to rest the arm initially for a few days to allow the pain and swelling to settle. This should then be followed by a specific and graduated rehabilitation program.
The process from injury to full recovery may take eight to twelve weeks as a ball park figure. This will obviously vary with any added complications. More elderly and infirm patients who do not have the ability to perform the regular, and in the later stages of rehabilitation, challenging routines, may need to settle for less movement and use in the arm than they had previously. The aim though is always what is best for every person as an individual.
It is believed that once stretched the muscles around the shoulder joint do not actually regain their previous length no matter how long they are rested. The only thing that excessive rest achieves is more stiffness, pain and function loss, hence the reason for early rehabilitation.
This does not mean the shoulder should be moved aggressively during the first seventy two hours after injury. A certain amount of immobilisation is necessary and should not be a concern.
The recovery process after a dislocated shoulder can seem slow and progress, after an initial improvement,can be tedious. However as always persistence is the shining light and with the correct advice, exercise and encouragement you will see success.
It is important to say that there are many cases of a dislocated shoulder that despite excellent rehabilitation become recurrent problems because the joint stability has been too severely compromised in the injury to be totally resolved with therapy. Such situations obviously need a qualified medical opinion as to the necessity and possibility of surgery.
In this case a program of rehabilitative exercises in preparation for and recovery from surgery for a dislocated shoulder will be helpful in achieving a solid result. Surgeons will have their own post operative regimes which need to be followed. Again there normally be an initial period of immobilisation or rest followed by progressive rehabilitation.
It would seem somewhat incomplete to not mention dislocation of the other joints in the shoulder. The other two joints,the acromio-clavicular and the sterno-clavicular, that may be problematic in this way are discussed in the Other Shoulder Injuries page.
I have put together as part of The Shoulder Set a complete book on The Dislocated Shoulder covering rehabilitation in all situations. i.e. non surgical and for before and after surgery. Please click here for more details.