Is an acromioclavicular (AC) distance of 10-13mm concerning for AC joint separation after a blunt injury, and should a patient with this condition avoid contact sports?

Acromioclavicular Distance of 10-13mm After Blunt Injury

An acromioclavicular distance of 10-13mm after blunt injury indicates a Grade III AC joint separation, which is a significant injury requiring immediate cessation of contact sports and a structured rehabilitation program before any consideration of return to play. 1

Understanding the Injury Severity

• Normal AC joint spacing is typically 3-8mm, making a measurement of 10-13mm clearly abnormal and diagnostic of complete disruption of both the acromioclavicular and coracoclavicular ligaments (Grade III injury). 1, 2

• Grade III AC separations represent complete ligamentous disruption with the clavicle displaced superiorly relative to the acromion, typically occurring from direct trauma to the shoulder with the arm adducted. 1, 3

• Radiography must be performed in upright positioning as malalignment can be significantly underrepresented on supine imaging, potentially leading to underestimation of injury severity. 1

Immediate Management and Activity Restrictions

Contact sports participation must be completely avoided immediately following diagnosis. 4, 5

• Initial management consists of complete rest from aggravating activities, sling immobilization for comfort (typically 1-2 weeks), ice application, and pain control with NSAIDs. 5, 2

• The decision between operative and non-operative management should be made within the first 7 days based on pain severity (VAS >7) and functional impairment. 4

• Non-operative treatment is increasingly favored for Grade III injuries as it demonstrates equivalent functional outcomes to surgery with significantly fewer complications and faster return to activities. 4, 2

Return to Contact Sports Criteria

Return to contact sports requires complete resolution of symptoms and restoration of full shoulder function, which typically takes 8-12 weeks with conservative management. 5, 2

Specific Return-to-Play Requirements:

• Pain-free full range of motion in all planes of shoulder movement must be achieved. 5, 2

• Strength testing must demonstrate at least 90% of contralateral shoulder strength in all rotator cuff and scapular stabilizer muscles. 5

• Functional testing must include sport-specific movements without pain or apprehension. 5

• Radiographic follow-up should confirm stable positioning of the AC joint without progressive displacement. 4

Rehabilitation Protocol Structure

Phase 1 (Weeks 0-2): Protection Phase

• Sling immobilization for comfort only, removing several times daily for gentle pendulum exercises. 5, 2
• Pain and inflammation control with ice and NSAIDs. 5
• Gentle passive range of motion within pain-free limits. 2

Phase 2 (Weeks 2-6): Motion Restoration Phase

• Progressive active-assisted and active range of motion exercises focusing on forward elevation, external rotation, and internal rotation. 5, 2
• Scapular stabilization exercises initiated early as scapular dyskinesis commonly accompanies AC injuries. 5
• Avoid cross-body adduction and horizontal adduction as these stress the healing AC joint. 5

Phase 3 (Weeks 6-12): Strengthening Phase

• Progressive rotator cuff strengthening with resistance bands and light weights. 5, 2
• Advanced scapular stabilization exercises including rows, push-up progressions, and dynamic stabilization drills. 5
• Sport-specific training initiated only after achieving pain-free full range of motion and adequate strength. 5

Critical Decision Points

Surgery should be considered only if: 4, 2

• Pain remains severe (VAS >7) at 7 days post-injury despite conservative measures
• Functional improvement plateaus after 6-8 weeks of structured rehabilitation
• Patient is a high-level athlete requiring cosmetic restoration or demanding overhead activities

Key advantages of non-operative management include: 4

• Significantly faster return to work and sports (average 6-8 weeks vs. 12-16 weeks with surgery)
• Zero complications compared to 24% complication rate with surgical intervention
• Equivalent functional outcomes at 1-year follow-up
• Option for delayed surgical reconstruction remains available if conservative treatment fails

Common Pitfalls to Avoid

• Do not assume that visible deformity necessitates surgery, as cosmetic appearance does not correlate with functional outcomes in Grade III injuries. 4, 2

• Do not allow premature return to contact sports even if the patient feels subjectively improved, as ligamentous healing requires minimum 8-12 weeks. 5

• Do not neglect scapular stabilization exercises, as scapular dyskinesis is both a consequence and perpetuating factor in AC joint dysfunction. 5

• Do not perform aggressive cross-body adduction stretching in the early phases as this stresses the healing AC joint and may worsen displacement. 5