Several ligaments surround this joint, and depending on the severity of the injury, one or all of the ligaments may be torn. Severe sprains tear the acromioclavicular and coracoclavicular ligaments.
The acromioclavicular joint is commonly injured when the clavicle is fractured.
Patients have pain and tenderness at the acromioclavicular joint.
Diagnosis
Anteroposterior x-rays of both sides of the clavicle are taken.
Acromioclavicular joint sprains are classified based on x-ray findings:
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Type I: No joint disruption
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Type II: Subluxation with some overlap of the clavicle and acromion
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Type III: Complete joint dislocation, usually because the coracoclavicular ligament is torn
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Type IV: Posterior displacement of the distal clavicle
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Type V: Superior displacement of the distal clavicle
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Type VI: Inferior displacement of the distal clavicle
Types IV, V, and VI are variants of type III.
