| Dislocation of a joint means that the joint surfaces, | | | | Subluxation of the joint can occur initially which involves |
| which are normally closely applied to each other, are | | | | one side of the joint coming off its opposite number to |
| completely disrupted and do not touch each other any | | | | a degree and then relocating suddenly into position. |
| longer. The joint capsule surrounds the joint and | | | | Shoulders can be dislocated voluntarily in some cases, |
| supports it and is often damaged as the joint surfaces | | | | although this may normally be connected with |
| move apart from their normal position. Dislocations | | | | psychiatric disorders. |
| may also result in damage to the joint surfaces | | | | Patients who have anterior shoulder dislocation |
| themselves as they move across each other in their | | | | typically have their arm slightly out to the side and |
| journey to the dislocated position. Joint, ligament and | | | | rotated outwardly, with an obvious bulge of the head |
| nerve injuries can occur during dislocations. | | | | of the humerus easily felt at the front of the shoulder. |
| Dislocations of the shoulder are the most common | | | | The shoulder muscles may be in spasm and any |
| form of dislocation of a joint, making up almost half of | | | | attempt to move is likely to cause extreme pain. |
| all of this type of injury. The commonest form of | | | | Posterior shoulder dislocations make a patient keep |
| dislocation is for the humeral head to be displaced | | | | their arm inwardly rotated and kept in to the side of |
| forwards, known as an anterior dislocation. This occurs | | | | the body and the humeral head can be felt posteriorly. |
| most often when the arm is out to the side, rotated | | | | This kind of injury can be missed or misclassified as |
| externally and moved backwards and there is a | | | | frozen shoulder. |
| forwards force on the upper arm, pushing the joint out | | | | The relocation of a shoulder dislocation is performed |
| in its position of vulnerability. A blow to the rear of the | | | | by surgeons in many different ways and the time from |
| arm, a fall on an outstretched hand (FOOSH) and a | | | | the incident to when the joint is finally relocated is the |
| strong outward rotation plus shoulder abduction can all | | | | important matter. If the time is too long the muscle |
| result in a dislocation. | | | | spasm increases and interferes with fixing the |
| Posterior shoulder dislocation is not frequent and | | | | dislocation. An original way was to put a foot in the |
| occurs with the arm turned inwards and across the | | | | person's axilla to make one end secure and traction |
| body, most often caused by muscle spasm in the | | | | the arm lengthways until the reduction is effected. |
| large back and chest muscles from an epileptic fit or | | | | Techniques have developed and an effective modern |
| an electrocution event. A downward joint dislocation | | | | way is to abduct the shoulder whilst pushing the |
| can occur if the arm is moved outwards and rotated | | | | humeral head anteriorly, then rotate the arm externally |
| outwardly with significant force, the arm bone levering | | | | and traction the arm, leading very often to success. |
| against the underside of the shoulder blade and so | | | | A significant part of a shoulder dislocation is pain and |
| pushing the joint out of place. The posterior dislocation | | | | doctors have many ways of ensure the best pain |
| is more commonly associated with side effects such | | | | relief and make the reduction process as easy as it |
| as damage to the nerves and blood vessels or an | | | | can be. If the dislocation is recent then the joint may be |
| injury to the shoulder rotator cuff muscles. | | | | relocated without much in the way of analgesics or |
| An atraumatic shoulder dislocation can occur with a | | | | muscle relaxing drugs. The best sedatives used have |
| tendency for the joint to be unstable in every direction, | | | | a fast mode of action, good muscular relaxation |
| often present in patients with joint hypermobility. | | | | properties and short duration of action so the patient |
| Multidirectional instability is the medical term given to this | | | | recovers quickly. Once relocated the arm should be |
| syndrome which presents in families, in younger people | | | | placed in a sling which may be retained for up to three |
| of less than 30 years and occurs in both shoulders. | | | | weeks to allow the capsular tear to heal. |