What are the differentials and management for shoulder pain after blunt force trauma?

Differential Diagnoses for Post-Traumatic Shoulder Pain in Roller Derby

After blunt force trauma during roller derby, the primary differential diagnoses include fractures (clavicle, scapula, or proximal humerus), acromioclavicular joint separation, glenohumeral dislocation, rotator cuff tear, and labral injury. 1

Bony Injuries

Fractures

• Clavicle fractures are among the most common traumatic shoulder injuries, particularly in young adults sustaining direct trauma or falls during contact sports 1, 2
• Proximal humerus fractures typically occur from high-impact trauma in younger patients or low-energy falls in older individuals 3
• Scapular fractures are less common but should be considered with high-energy blunt trauma 1
• Unstable or significantly displaced fractures require acute surgical management 1

Joint Injuries

• Acromioclavicular (AC) joint separation results from direct trauma to the shoulder and is extremely common in contact sports 1, 2
• Glenohumeral dislocation (anterior most common) occurs from high-impact trauma and presents with the patient holding the affected arm with the contralateral hand, visible deformity, and severe pain with any motion 3
• AC dislocations can be missed on standard AP views, making axillary or scapula-Y views essential 1

Soft Tissue Injuries

Rotator Cuff Pathology

• Acute rotator cuff tears are frequently underreported because patients may not seek immediate treatment 1
• These injuries cause difficulty with overhead activities, night pain, and inability to hold the arm in elevated position 3, 4
• Most rotator cuff tears can undergo conservative management before considering surgery 1

Labral and Capsular Injuries

• Labral tears (including Bankart and SLAP lesions) occur with traumatic dislocations or direct trauma 1
• Labroligamentous complex injuries are common soft-tissue injuries requiring evaluation 1
• These typically can be managed conservatively initially unless associated with joint instability requiring acute surgical intervention 1

Initial Diagnostic Approach

Clinical Examination Priorities

• Document the exact mechanism of injury, including direction of force, position at impact, and immediate symptoms 5, 2
• Assess neurovascular status immediately: pulse strength, capillary refill, sensation in axillary/radial/median/ulnar distributions, and motor function 5
• Palpate for point tenderness over clavicle, AC joint, humeral head position, and scapula 2, 3
• Evaluate for visible deformity, particularly a palpable humeral head in the axilla or dimple inferior to the acromion suggesting dislocation 3

Imaging Strategy

• Obtain upright radiographs with minimum three views: AP in internal rotation, AP in external rotation, and axillary or scapula-Y view 1
• The axillary or scapula-Y view is absolutely critical as AC and glenohumeral dislocations are frequently misclassified on AP views alone 1
• Upright positioning is essential because shoulder malalignment can be underrepresented on supine films 1
• Radiography effectively diagnoses displaced fractures and shoulder malalignment, which are the primary acute management concerns 1

Advanced Imaging Indications

When Radiographs Are Insufficient

• MRI without contrast is effective for diagnosing most traumatic soft-tissue pathology including rotator cuff tears, labral tears, and assessing bone loss 1
• CT is superior to radiography for characterizing complex fracture patterns when surgical planning is needed 1
• CT angiography is the preferred study if vascular compromise is suspected (diminished pulses, expanding hematoma, signs of ischemia) 1

Management Algorithm

Immediate Surgical Referral Required

• Glenohumeral or AC joint dislocation (for reduction) 2, 3
• Displaced or unstable proximal humerus fractures 2, 3
• Type IV, V, or VI AC joint injuries 2
• Any signs of vascular compromise 1
• Open fractures 1

Conservative Management Appropriate

• Nondisplaced or minimally displaced clavicle fractures 2, 3
• Type I and II AC separations 2, 3
• Most rotator cuff tears initially 1
• Labral tears without instability 1

Conservative Treatment Components

• Sling immobilization for comfort (short-term use) 2, 3
• Pain management with NSAIDs or other analgesics 2, 3
• Early range-of-motion exercises as tolerated 3
• Progressive strengthening program 3

Critical Pitfalls to Avoid

• Failing to obtain axillary or scapula-Y views, which leads to missed dislocations 1
• Inadequate neurovascular examination documentation, particularly in high-energy trauma 5
• Performing supine rather than upright radiographs, which underrepresents malalignment 1
• Missing growth plate injuries in younger athletes, though this is more relevant for adolescent players 5
• Underestimating the severity of AC joint injuries based on AP views alone 1