What is the treatment for a widened acromioclavicular joint?

Treatment of Widened Acromioclavicular Joint

A widened acromioclavicular (AC) joint represents ligamentous injury requiring treatment based on injury severity: Types I-II injuries should be managed conservatively with sling immobilization and early rehabilitation, while Types IV-VI require surgical intervention, and Type III injuries warrant individualized decision-making favoring surgery for high-demand patients and overhead athletes. 1, 2, 3

Initial Diagnostic Imaging

• Standard radiography is the mandatory first imaging study, requiring three views: anteroposterior (AP) in internal and external rotation, plus an axillary or scapula-Y view, performed with the patient upright 4
• Obtain orthogonal views to prevent misclassification of AC joint displacement and avoid underestimating injury severity 4
• If radiographs show widening but injury classification remains unclear, MRI without contrast (rating 7/9) or MR arthrography (rating 9/9) can evaluate associated soft tissue injuries including superior labrum anterior posterior (SLAP) tears 4, 2

Classification-Based Treatment Algorithm

Type I and Type II Injuries (Mild Sprains)

• Initiate sling immobilization immediately with ice application to reduce pain and swelling 1, 5
• Begin early shoulder motion exercises once acute pain subsides, typically within 3-7 days 2
• Progress to physical therapy focusing on range of motion and rotator cuff strengthening 6, 2
• Return to activity when normal shoulder motion and strength match the contralateral extremity and the shoulder is asymptomatic 2
• Expected outcome: excellent with full return of function 5

Type III Injuries (Complete AC Ligament Disruption, Intact Deltotrapezial Fascia)

Treatment remains controversial and depends on patient functional demands 2, 7

Conservative approach:

• Sling immobilization with early functional rehabilitation can achieve return to previous functional activity levels 2, 7
• Studies demonstrate no distinct advantage for surgical reconstruction over nonoperative treatment in general populations 7

Surgical approach is favored for:

• Patients placing high functional demands on their shoulders 2
• Athletes participating in overhead sports 2
• Individuals requiring anatomic reduction for occupational demands 3

Type IV, V, and VI Injuries (High-Grade Dislocations)

• Immediate orthopedic referral for surgical management is mandatory 4, 1, 2
• Surgical goals include anatomic reduction of the AC joint, reconstruction of coracoclavicular ligaments, and repair of deltotrapezial fascia 2
• Delaying surgical referral makes stabilization more technically challenging 4

Surgical Techniques Available

Multiple reconstruction options exist, including:

• Coracoclavicular screw fixation 3
• Coracoacromial ligament transfer 1, 3
• Anatomic coracoclavicular ligament reconstruction (open or arthroscopic, with or without graft augmentation) 3
• Dynamic transfer of conjoined tendon 1
• AC ligament repair 1

Pain Management During Conservative Treatment

• Start with acetaminophen as first-line oral analgesic due to favorable safety profile 6
• If inadequate relief, use NSAIDs at the lowest effective dose for shortest duration 6

Critical Pitfalls to Avoid

• Failing to obtain proper radiographic views (three views minimum) leads to missed injury severity 4
• Inadequate imaging causing underestimation of fracture components or ligamentous disruption 4
• Treating Type IV-VI injuries conservatively when surgery is indicated 1, 2
• Neglecting to evaluate for associated glenohumeral injuries, particularly SLAP tears, which have increased incidence with AC joint injuries 2

Rehabilitation Principles

• Proper shoulder positioning during rehabilitation prevents further injury and promotes healing 6
• Address scapular dyskinesis, poor posture, and muscle imbalances that contribute to ongoing symptoms 6
• Gradually increase active range of motion while restoring alignment and strengthening weak shoulder girdle muscles 6

Expected Outcomes

• Nonsurgical treatment of Types I-III: excellent outcomes with full functional return in most cases 5, 7
• Surgical reconstruction: satisfactory pain relief and return to functional activities, though biomechanical improvements in construct strength remain necessary to prevent loss of reduction with cyclic loading 2