Acromioclavicular joint dissociation - type IV
Presentation
Painful left shoulder after sports tackle.
Patient Data
Age: 25 years
Gender: Male
From the case:
Acromioclavicular joint dissociation - type IV
X-ray
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Frontal
Glenohumeral joint is normally aligned. Posterior superior dislocation of the clavicle at the acromioclavicular joint. No fracture identified.
From the case:
Acromioclavicular joint dissociation - type IV
CT
Axial bone window
The distal clavicle is displaced posteriorly with respect to the acromion, protruding into the trapezius muscle. The glenohumeral joint is normally aligned. No shoulder or rib fractures.
Case Discussion
Posterior dislocation of the distal clavicle with respect to the acromion, with the clavicle protruding into the trapezius muscle is a type IV ACJ injury.