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Shoulder Separation

Shoulder Separation Overview

A shoulder separation occurs after a fall or a sharp blow to the top of the shoulder. This injury is usually sports related or due to car accidents or falls. This is not the same as a shoulder dislocation, which occurs at the large joint where the arm attaches to the shoulder, although the two may appear to be the same.

The shoulder separation, or acromioclavicular (AC) dislocation, is an injury to the junction between the collarbone and the shoulder. It is usually a soft-tissue or ligament injury but may include a fracture (broken bone). In severe shoulder separations, the coracoclavicular (CC) ligament is also injured.

Depending on the damage done to the joint, there are different classifications (grades) to define the amount of injury:

  • Type I: The AC ligament is partially torn, but the CC ligament is not injured.
  • Type II: The AC ligament is completely torn, and the CC ligament is either not injured or partially torn. The collarbone is partially separated from the acromion.
  • Type III: Both the AC and CC ligaments are completely torn. The collarbone and the acromion are completely separated.
  • Types IV through VI: These are uncommon and involve tearing of the muscles across the shoulder and neck.
Medically Reviewed by a Doctor on 3/11/2015

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Acromioclavicular Joint Separations »

The acromioclavicular (AC) joint is a diarthrodial articulation with an interposed fibrocartilaginous meniscal disk that links the hyaline cartilage articular surfaces of the acromial process and the clavicle.

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