A diagnosis of shoulder dislocation is often suspected based on the person's history and physical examination. Radiographs are made to confirm the diagnosis. Most dislocations are apparent on radiographs showing incongruence of the glenohumeral joint. Posterior dislocations may be hard to detect on standard AP radiographs, but are more readily detected on other views. After reduction, radiographs are usually repeated to confirm successful reduction and to detect bone damage. After repeated shoulder dislocations, an MRI scan may be used to assess soft tissue damage. In regards to recurrent dislocations, the apprehension test (anterior instability) and sulcus sign (inferior instability) are useful methods for determining predisposition to future dislocation. There are three main types of dislocations: anterior, posterior, and inferior. Anterior (forward) X-ray at left shows anterior dislocation in a young man. X-ray at right shows the same shoulder after reduction and internal rotation, revealing a Bankart lesion and a Hill-Sachs lesion. In over 95% of shoulder dislocations, the humerus is displaced anteriorly. In most of those, the head of the humerus comes to rest under the coracoid process, referred to as sub-coracoid dislocation. Sub-glenoid, subclavicular, and, very rarely, intrathoracic or retroperitoneal dislocations may also occur. Anterior dislocations are usually caused by a direct blow to, or fall on, an outstretched arm. The person typically holds his/her arm externally rotated and slightly abducted. A Hill–Sachs lesion is an impaction of the head of the humerus left by the glenoid rim during dislocation. Hill-Sachs deformities occur in 35–40% of anterior dislocations. They can be seen on a front-facing X-ray when the arm is in internal rotation. Bankart lesions are disruptions of the glenoid labrum with or without an avulsion of bone fragment. Damage to the axillary artery and axillary nerve (C5, C6) may result. The axillary nerve is injured in 37% making it the most commonly injured structure with this type of injury. Other common, associated, nerve injuries include injury to the suprascapular nerve (29%) and the radial nerve (22%). Axillary nerve damage results in a weakened or paralyzed deltoid muscle and as the deltoid atrophies unilaterally, the normal rounded contour of the shoulder is lost. A person with injury to the axillary nerve will have difficulty in abducting the arm from approximately 15° away from the body. The supraspinatus muscle initiates abduction from a fully adducted position. File:Luxation epaule.An anterior dislocation of the shoulder File:AnterDisAPMark.Anterior dislocation of the right shoulder. AP X ray File:AnterDisMark.Anterior dislocation of the right shoulder. Y view X ray. Posterior (backward) Lightbulb sign indicative of posterior shoulder dislocation shown on the left. On the right, the same shoulder after reduction. Posterior dislocations are uncommon, and are typically due to the muscle contraction from electric shock or seizure. They may be caused by strength imbalance of the rotator cuff muscles. People with<unk> s typically present holding their arm internally rotated and adducted, and exhibiting flattening of the anterior shoulder with a prominent coracoid process. Posterior dislocations may go unrecognized, especially in an elderly person and in people who are in the state of unconscious trauma. An average interval of 1 year was noted between injury and diagnosis in a series of 40 people. Inferior (downward) abducted. Also present is a fracture of the greater tuberosity. Inferior dislocation is the least likely, occurring in less than 1%. 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. Such injuries have a high complication rate as many vascular, neurological, tendon, and ligament injuries are likely to occur from this mechanism of injury.
Dislocated shoulder
Separated shoulder
Sprained ankle
Scapular fracture
Back strain
Sacral fracture
Milwaukee shoulder syndrome
Elbow fracture