Merck Manual

Please confirm that you are a health care professional

honeypot link

Acromioclavicular Joint Sprains

(Shoulder Separation; AC Joint Sprain)

By

Danielle Campagne

, MD, University of California, San Francisco

Medically Reviewed Mar 2021 | Modified Sep 2022
View Patient Education
Topic Resources

Acromioclavicular joint sprains are common, usually resulting from a fall on the shoulder or, less often, an outstretched arm.

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.

Ligaments of the shoulder joint

Ligaments of the shoulder joint

Diagnosis of Acromioclavicular Joint Sprains

  • X-rays

Anteroposterior x-rays of both sides of the clavicle are taken.

Acromioclavicular joint sprains are classified based on x-ray findings:

  • Type I: No joint disruption

  • Type II: Subluxation with some overlap of the clavicle and acromion

  • Type III: Complete joint dislocation, usually because the coracoclavicular ligament is torn

  • Type IV: Posterior displacement of the distal clavicle

  • Type V: Superior displacement of the distal clavicle

  • Type VI: Inferior displacement of the distal clavicle

Types IV, V, and VI are variants of type III.

Treatment of Acromioclavicular Joint Sprains

  • Immobilization with a sling

  • Early range-of-motion exercises

  • For some severe sprains, surgery

Treatment of acromioclavicular joint sprains is usually immobilization (eg, with a sling) and early range-of-motion exercises.

Some severe sprains (usually type III) are surgically repaired and require outpatient orthopedic referral.

View Patient Education
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz! 
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP