What is the appropriate workup for a patient presenting with shoulder pain?

Workup for Shoulder Pain

Start with standard shoulder radiographs including anteroposterior (AP) views in internal and external rotation plus an axillary or scapular Y view—this is the appropriate initial imaging for all patients presenting with shoulder pain regardless of suspected etiology. 1, 2

Initial Imaging: Radiography

• Obtain at least three views with two being orthogonal to adequately assess the shoulder joint 1, 2
• The axillary lateral or scapular Y view is critical because glenohumeral and acromioclavicular dislocations can be missed on AP views alone 2, 3
• Perform radiographs upright rather than supine, as shoulder malalignment is underrepresented on supine imaging 2, 3
• A Grashey projection (30° posterior oblique) profiles the glenohumeral joint optimally in trauma cases 1

Clinical Assessment Alongside Imaging

• Identify mechanism of injury, timing (acute vs chronic), location of pain, and functional limitations to guide subsequent imaging 4, 5
• Perform targeted physical examination to distinguish between rotator cuff pathology, instability, labral tears, impingement, and referred pain from cervical spine or thoracic outlet 4, 6
• Consider non-musculoskeletal causes including lung pathology, pleural disease, or subdiaphragmatic processes that refer pain through the phrenic nerve if musculoskeletal examination is unrevealing 6

Advanced Imaging Based on Clinical Suspicion

For Suspected Occult Fracture (Normal/Nonspecific Radiographs)

• Order CT shoulder without contrast for detailed osseous evaluation with high spatial resolution to identify subtle nondisplaced fractures 1
• MRI shoulder without contrast is an equivalent alternative that demonstrates bone marrow edema from trauma and identifies associated soft tissue injuries 1

For Confirmed Fracture on Radiographs

• CT shoulder without contrast is the next appropriate study for characterizing complex fracture patterns, displacement, and angulation, particularly for preoperative planning 1, 2
• MRI shoulder without contrast may be appropriate only if assessing rotator cuff injury in patients not planned for surgical fracture fixation 1

For Suspected Dislocation or Instability

• MRI shoulder without contrast is the next appropriate imaging study because acute dislocation creates posttraumatic joint effusion or hemarthrosis that provides sufficient visualization of soft tissue structures without arthrography 1
• CT shoulder without contrast may be appropriate when MRI assessment of bone loss (Hill-Sachs or glenoid defects) is limited 1
• MR arthrography may be appropriate for detailed labral evaluation but is generally unnecessary in acute settings due to natural joint distention from effusion 1

For Suspected Labral Tear (Negative/Indeterminate Radiographs)

• In acute trauma, MRI shoulder without contrast is preferred because posttraumatic joint effusion provides adequate soft tissue visualization 1
• In subacute or chronic settings (when joint effusion has resolved), MR arthrography is the reference standard with a 9/9 appropriateness rating, particularly for patients under 35 years 1, 2
• CT arthrography is appropriate only when MRI is contraindicated 1

For Suspected Rotator Cuff Tear (Negative/Indeterminate Radiographs)

• MRI shoulder without contrast or ultrasound are equivalent alternatives (both rated 9/9) and only one study needs to be ordered 1, 2
• MRI is preferred when there is large body habitus, restricted range of motion from acute pain, or suspicion of concurrent intraarticular pathology like labral tears 1
• Ultrasound effectiveness depends on local expertise and operator skill 1

For Suspected Septic Arthritis

• Ultrasound-guided or fluoroscopic-guided arthrocentesis with aspiration and fluid analysis is the procedure of choice (rated 9/9) 1, 2
• MRI shoulder with and without contrast may be appropriate only if clinical concern warrants imaging before or after aspiration, but aspiration remains the diagnostic priority 1

Common Pitfalls to Avoid

• Do not rely on AP views alone for trauma evaluation—the axillary or scapular Y view is essential to detect posterior dislocations which are frequently missed 2, 3
• Do not order MR arthrography in acute trauma settings when natural joint effusion already provides adequate distention for soft tissue visualization 1
• Do not assume shoulder pain is always musculoskeletal—maintain suspicion for referred pain from cervical radiculopathy, thoracic outlet syndrome, or intrathoracic pathology when examination findings are inconsistent 6, 7
• Avoid treating imaging abnormalities that are asymptomatic, as many rotator cuff tears and degenerative changes are incidental findings in older patients 7