What to do when the clavicle and the humeral head rub against each other?

Management of Clavicle and Humeral Head Impingement

When the clavicle and humeral head rub against each other, this represents a form of shoulder impingement that requires proper diagnostic imaging and treatment. Initial management should include radiographic evaluation with anteroposterior (AP) views in internal and external rotation and an axillary or scapula-Y view to properly assess the shoulder alignment and bony structures. 1

Diagnostic Approach

Initial Imaging

1. Standard radiographs are the preferred initial study:
   • Anteroposterior (AP) views in internal and external rotation
   • Axillary or scapula-Y view (critical for proper evaluation)
   • Upright positioning (malalignment can be underrepresented on supine radiography)
   • Additional Bernageau view may help demonstrate bone loss 1

Advanced Imaging (if needed)

• MRI without contrast is effective for assessing bony morphology and soft tissue injuries that may be contributing to the impingement 1
• CT scan may be indicated if complex bony anatomy or fracture patterns are suspected 1
• MR arthrography is considered the gold standard for evaluating intra-articular pathology if suspected 1

Treatment Algorithm

Conservative Management

1. Activity modification to avoid positions that cause impingement
2. Physical therapy focusing on:
   • Proper scapular positioning
   • Rotator cuff strengthening
   • Posture correction
3. Anti-inflammatory medications to reduce pain and inflammation
4. Corticosteroid injections may be considered for persistent symptoms

Surgical Considerations

Surgical intervention may be necessary if:

• Conservative management fails
• There is evidence of structural abnormality causing impingement
• Significant functional limitation persists

Surgical options may include:

• Distal clavicle resection
• Acromioplasty
• Addressing any associated rotator cuff pathology

Special Considerations

Anatomical Variants

Unusual bony processes at the acromial end of the clavicle may contribute to impingement with the humeral head, as described in case reports 2. These variants should be identified on imaging studies as they may require specific surgical approaches.

Associated Injuries

When evaluating clavicle and humeral head impingement, be alert for:

• Rotator cuff tears (particularly of the subscapularis) 3
• Acromioclavicular joint pathology
• Glenohumeral instability

Pitfalls to Avoid

• Inadequate imaging: Failure to obtain proper radiographic views, especially axillary views, can lead to missed diagnoses of shoulder malalignment 1
• Overlooking associated soft tissue injuries: Up to 40% of humeral head fractures have associated rotator cuff tears 1
• Delayed treatment: Chronic impingement can lead to progressive damage of the rotator cuff and glenohumeral joint

Follow-up Recommendations

• Regular assessment of pain, range of motion, and function
• Repeat imaging if symptoms worsen or fail to improve with conservative management
• Consider referral to shoulder specialist if symptoms persist beyond 3 months of appropriate conservative care

By following this structured approach to diagnosis and treatment, most cases of clavicle and humeral head impingement can be effectively managed to reduce pain and restore shoulder function.