dislocation of shoulder

Etiology

The most common cause is from trauma with the arm in external rotation with abduction, causing the head of the humerus to sublux anteriorly; a posterior subluxation may occur from a fall on an outstretched arm. An inferior dislocation may occur from poor muscle tone as with hemiplegia and from the weight of the arm pulling the humerus downward. Anterior glenohumeral dislocations are common among athletes, esp. football players.

Signs

A patient with a dislocated shoulder usually has a hollow in place of the normal bulge of the shoulder, as well as a slight depression at the outer end of the clavicle. Glenohumeral range of motion is restricted and such patients often cannot touch their opposite shoulder with the hand of the involved arm. Both shoulders should always be compared for symmetry. Vital signs are assessed to provide baseline data. The patient is assessed for pain, and analgesia prescribed and provided as needed.

Treatment/First Aid

Radiographs and/or MRI are needed to determine the type of dislocation and the presence of any fracture. If no fractures are present, one of several maneuvers can be used to reduce the humerus into the glenoid.

Patient care

Because of the potential damage to neurovascular structures as they cross the glenohumeral joint line, the vascular and neurological status of the arm and hand must be assessed. A decreased or diminished ulnar or radial pulse warrants immediate intervention and reduction of the dislocation. An anterior dislocation of the shoulder can be reduced, for example, with passive traction on the arm or by placing the patient in a supine position and medially displacing the scapula. A sling or other shoulder support is provided after reduction to limit shoulder mobility for the prescribed time, and activity is gradually resumed using a guided rehabilitation protocol.