Imaging for Shoulder Pain with Numbness
Begin with plain radiographs (minimum three views: AP internal and external rotation plus axillary or scapular-Y), then proceed directly to MRI of the cervical spine and shoulder without contrast to evaluate for nerve compression and concurrent soft-tissue pathology.
Initial Radiographic Evaluation
Obtain plain shoulder radiographs first with at least three views (AP internal rotation, AP external rotation, and axillary or scapular-Y view) to exclude fracture, dislocation, or arthritis before pursuing advanced imaging. 1, 2, 3
The axillary or scapular-Y view is mandatory—AP views alone frequently miss acromioclavicular and glenohumeral dislocations that can cause neurologic symptoms. 2, 3
Upright positioning is essential because supine films may underestimate malalignment. 3
Addressing the Numbness Component
Numbness suggests nerve involvement (cervical radiculopathy, brachial plexopathy, or peripheral nerve compression such as suprascapular or axillary nerve injury), which requires evaluation beyond standard shoulder imaging.
MRI of the cervical spine without contrast should be obtained when numbness accompanies shoulder pain to assess for cervical nerve root compression, disc herniation, or spinal stenosis that may refer pain to the shoulder.
MRI of the shoulder without contrast simultaneously evaluates rotator cuff tears, labral pathology, and masses (e.g., paralabral cysts) that can compress nerves and cause both pain and numbness. 1, 2, 3
Advanced Imaging Algorithm After Radiographs
If Radiographs Show Fracture or Dislocation
Order CT shoulder without contrast to delineate fracture planes and guide surgical planning. 1, 2, 3
If neurologic symptoms persist despite fracture management, add MRI shoulder without contrast to assess nerve injury or soft-tissue pathology. 2
If Radiographs Are Normal or Nonspecific
MRI shoulder without contrast is the primary advanced modality because it:
- Detects occult fractures via bone-marrow edema 1, 2, 3
- Evaluates rotator cuff tears (90–91% sensitivity, 93–95% specificity for full-thickness tears) 1, 3
- Identifies labral tears, especially in acute trauma where joint effusion provides natural contrast 1, 2, 3
- Visualizes nerve-compressing lesions such as paralabral cysts or masses 1
Ultrasound may substitute for MRI when evaluating rotator cuff tears if MRI is contraindicated (e.g., metallic hardware causing artifact), but ultrasound cannot assess deep nerve structures or labral pathology. 1, 3
Special Considerations for Numbness
If cervical spine MRI is normal and numbness persists, consider electrodiagnostic studies (EMG/NCS) to localize peripheral nerve lesions.
Do not order MR arthrography in acute trauma—the post-traumatic effusion already provides sufficient joint contrast, and arthrography is unnecessary and potentially harmful in the acute phase. 1, 2, 3
Common Pitfalls to Avoid
Never skip the axillary or scapular-Y view—dislocations causing nerve injury are frequently missed without these projections. 2, 3
Do not assume shoulder pathology alone explains numbness—cervical radiculopathy is a common mimic and requires dedicated cervical spine imaging.
Avoid relying solely on ultrasound for patients with numbness, as it cannot evaluate nerve roots, the cervical spine, or deep labral/capsular structures. 3
Do not order routine IV contrast for shoulder MRI—it provides no added diagnostic value for nerve or soft-tissue evaluation. 1