UMEM Educational Pearls

Title: AC Joint Injuries

Category: Orthopedics

Keywords: AC Joint, Separation, Dislocation (PubMed Search)

Posted: 9/26/2009 by Michael Bond, MD (Updated: 11/22/2024)
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AC Joint Dislocations

The acromioclavicular (AC) Joint is commonly injured when a person falls onto their shoulder.

The AC Joint consists of three ligaments:

Injuries to this joint are classified as Type I – Type VI and involve sprain or tears of the AC or CC ligaments

Type I – Is a sprain of the joint without complete tear of either the AC or CC ligament
Type II – Does not show significant elevation of the lateral end of the clavicle but is due to a tear of the AC ligament.
Type III – Results from tears in the AC and CC ligament. Noted by > 5 mm elevation of the AC joint.
Types IV – VI : are associated with complications of a Type III injury.