Diagnosis is based on physical examination and an x-ray. A physical examination can identify point tenderness, pain at the AC joint with cross-arm adduction, and pain relief with an injection of a local anesthetic. The cross-arm adduction will produce pain specifically at the AC joint and will be done by elevating the arm to a 90° angle, flexing the elbow to a 90° angle, and adducting the arm across the chest. The pain in the shoulder is hard to pinpoint due to the shared innervation of the AC joint and the glenohumeral joint. An injury to the AC joint will result in pain over the AC joint, in the anterolateral neck and in the region in the anterolateral deltoid. X-ray indicates a<unk>  when the acromioclavicular joint space is widened (it is normally 5 to 8 mm). It can be classified into 6 types. Type I A Type I AC separation involves direct trauma to the shoulder causing the injury to ligaments that form the joint, but no severe tearing or fracture. It is commonly referred to as a sprain. For a type 1 AC separation, the joint does not lose stability. Type II A Type II AC separation involves complete tearing of the acromioclavicular ligament, as well as a partial tear (but not a full tear) of the coracoclavicular ligaments. This often causes a noticeable bump on the shoulder and partial or incomplete dislocation. This bump is permanent. The clavicle is unstable to direct stress examination. On radiographs, the lateral end of the clavicle may be slightly elevated by pressing on the sternal aspect of the clavicle forcing the acromial end down, and by releasing, it may pop back up eliciting a piano key sign due to the tearing of the AC. Type III Type 3 AC joint separation on plain X ray In a Type III AC separation both acromioclavicular and coracoclavicular ligaments are torn without significant disruption of the deltoid or trapezial fascia. A significant bump, resulting in some shoulder deformity, is formed by the lateral end of the clavicle. This bump, caused by the clavicle's dislocation, is permanent. The clavicle can be moved in and out of place on the shoulder. A radiographic examination will show the results as abnormal. Type IV This is a type III injury with avulsion of the coracoclavicular ligament from the clavicle, with the distal clavicle displaced posteriorly into or through the trapezius and may tent the posterior skin. A displaced clavicle is easily seen on a radiograph. It is important to evaluate the sternoclavicular joint also, because there can be an anterior dislocation of the sternoclavicular joint and posterior dislocation of the AC joint. This injury is generally acknowledged to require surgery. Type V This is a more severe form of a type III injury, with the trapezial and deltoid fascia stripped off of the acromion as well as the clavicle. This is type III but with exaggeration of the vertical displacement of the clavicle from the scapula. Distinguishing between Type III and Type V separations based on radiographs is difficult and often unreliable between surgeons. Type V is manifested by a 2- to 3-fold increase in the coracoclavicular distance. The shoulder manifests as a severe droop, secondary to downward displacement of the scapula and humerus due to loss of the clavicular strut. This injury generally requires surgery. Type VI This is type III with inferior dislocation of the distal end of the clavicle below the coracoid. This injury is associated with severe trauma and frequently accompanied by multiple other injuries. The mechanism is thought to be severe hyperabduction and external rotation of the arm, combined with retraction of the scapula. The distal clavicle is found in 2 orientations, either subacromial or subcoracoid. With the subcoracoid dislocation, the clavicle becomes lodged behind the intact conjoined tendon. The posterior superior AC ligaments, which often remain attached to the acromion, get displaced into the AC interval, making anatomic reduction difficult. The tissue needs to be surgically cleared and then reattached after reduction. Most patients with type VI injuries have paresthesia that resolves after relocation of the clavicle It is extremely rare and generally only involved with motor vehicle collisions. This requires surgery. Classification type 1 of AC separation.Classification type 1 is the most common type Classification type 2 of AC separation.Classification type 2 Classification type 3 of AC separation.Classification type 3 Classification type 4 of AC separation.Classification type 4 Classification type 5 of AC separation.Classification type 5 is rare Classification type 6 of AC separation.Classification type 6 is rare
Separated shoulder
Dislocated shoulder
Clavicle fracture
Scapular fracture
Sacral fracture
Sprained ankle
Back strain
Scaphoid fracture