Dislocated shoulder

Dislocated shoulder
Specialty	Emergency medicine

A dislocated shoulder occurs when the humerus separates from the scapula at the glenohumeral joint. As the most maneuverable joint in the human body, the shoulder is the joint most vulnerable to dislocation. Approximately half of major joint dislocations seen in emergency departments are of the shoulder. Partial dislocation of the shoulder is referred to as subluxation.

Types

Anterior (forward)

Over 95% of shoulder dislocation cases are anterior. Most anterior dislocations are sub-coracoid. Sub-glenoid; subclavicular; and, very rarely, intrathoracic or retroperitoneal dislocations may occur.

Posterior (backward)

Posterior dislocations are occasionally due to electrocution or seizure and may be caused by strength imbalance of the rotator cuff muscles. Posterior dislocations often go unnoticed, especially in an elderly patient. An average interval of 1 year was discovered between injury and diagnosis of posterior dislocation in a series of 40 patients.

Inferior (downward)

Inferior dislocation is the least likely form, occurring in less than 1% of all shoulder dislocation cases. This condition is also called luxatio erecta because the arm appears to be permanently held upward or behind the head. It is caused by a hyper abduction of the arm that forces the humeral head against the acromion. Inferior dislocations have a high complication rate as many vascular, neurological, tendon, and ligament injuries are likely to occur from this kind of dislocation.

Signs

• Significant pain, which can sometimes be felt past the shoulder, along the arm.
• Inability to move the arm from its current position, particularly in positions with the arm reaching away from the body and with the top of the arm twisted toward the back.
• Numbness of the arm.
• Visibly displaced shoulder. Some dislocations result in the shoulder appearing unusually square.

Treatment

Initial

Prompt professional medical treatment should be sought for any suspected dislocation injury. Usually, a dislocated shoulder is kept in its current position by use of a splint or sling (however, see below). A pillow between the arm and torso may provide support and increase comfort. Ice may help reduce pain.

Emergency department care is focused on returning the shoulder to its normal position via processes known as reduction. Normally, closed reduction, in which several methods are used to manipulate the bone and joint from the outside, is used. A variety of techniques exist, but some are preferred due to fewer complications or easier execution. In cases where closed reduction is not successful, surgical open reduction may be needed. Following reduction, X-Ray imaging is often used to ensure that the reduction was successful and there are no fractures. The arm should be kept in a sling or immobilizer for several days, preferably until orthopedic consultation. Hippocrates method is not used anymore. Hippocrates used to place the heel in the axilla and reduce shoulder dislocations. Kocher's method, the most popular method of reducing shoulder dislocation, should be done only under anesthesia as the patient may go in neurogenic shock because of the pain. Traction is applied on the arm and it is abducted. Then, it is externally rotated, and the arm is adducted following which it is internally rotated and maintained in the position with the help of a sling. A check xray should be taken to confirm whether the head of humerus has reduced back into the glenoid cavity

Post-reduction: Is a sling really necessary?

For thousands of years, treatment of dislocated shoulders has included immobilization of the patient's arm in a sling, with the arm placed in internal rotation. However, recent studies performed on both cadavers and humans have found that immobilizing the arm in such position doesn't do any good and that much better results are obtained if the arm is immobilized in external rotation, 90 degrees from the body.

Other studies have found that the use of a sling doesn't do any good at all, and that the rate of recurrent dislocation of the patients who did not wear a sling was the same as the patients who did.

Therapy

In many cases, particularly for individuals not subject to high occupational risk of dislocation, physical therapy and/or occupational therapy can strengthen the shoulder and produce satisfactory shoulder stability. After pain and swelling have been controlled or stopped, the patient will enter a rehabilitation program that includes exercises to restore the range of motion of the shoulder and strengthen the muscles to prevent future dislocations. These exercises may start at simple motions of the arm to the use of weights.

Surgery

Some cases require non-emergency surgery to repair damage to the tissues surrounding in the shoulder joint and restore shoulder stability. Arthroscopic surgery techniques may be used to repair the glenoidal labrum, capsular ligaments, biceps long head anchor or SLAP lesion and/or to tighten the shoulder capsule. .

The time-proven surgical treatment for recurrent anterior instability of the shoulder is a Bankart repair . When the front of the shoulder socket has been broken or worn, a bone graft may be required to restore stability . When the shoulder dislocates posteriorly (out the back), a surgery to reshape the socket may be necessary .

New procedure that should be investigated as an option as opposed to open surgery. http://orthoinfo.aaos.org/topic.cfm?topic=A00034

See also

• Shoulder problems
• Shoulder surgery
• Reduction (orthopedic surgery)

External links

• dislocated shoulders at Mayo Clinic
• Arthroscopic shoulder surgery for shoulder dislocation, subluxation, and instability: why, when and how it is done. at University of Washington
• emedicinehealth.com Patient education article -- Shoulder Dislocation
• catalog.nucleusinc.com -- Shoulder Dislocation