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Acromioclavicular Joint Sprains

(Shoulder Separation; AC Joint Sprain)

By

Danielle Campagne

, MD, University of San Francisco - Fresno

Last full review/revision Mar 2021| Content last modified Mar 2021

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

(See also Overview of Sprains and Other Soft-Tissue Injuries.)

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

  • 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

  • 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.

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