Pain Under the Scapula Radiating to the Shoulder: Differential Diagnosis
Pain beneath the scapula that radiates to the shoulder most commonly indicates either cervical radiculopathy (particularly C5-C8 nerve roots) or rotator cuff pathology, with the specific location and pain characteristics helping distinguish between these two primary causes 1, 2.
Primary Diagnostic Considerations
Cervical Radiculopathy
This is a critical diagnosis that must not be missed. Scapular pain is present in 72% of cervical radiculopathy cases and may actually precede arm pain by several weeks 1. The specific nerve root involved determines the pain pattern:
- C5 radiculopathy: Pain in the suprascapular region with both superficial and deep pain characteristics 2
- C6 radiculopathy: Pain from suprascapular to posterior deltoid region, typically deep pain only 2
- C7 radiculopathy: Interscapular pain, deep pain only, and is the most common root level associated with scapular pain 1, 2
- C8 radiculopathy: Interscapular and scapular pain with both superficial and deep components 2
A key clinical pearl: patients with C5 or C8 radiculopathy experience both superficial and deep pain, while C6 or C7 radiculopathy typically causes only deep pain 2. This distinction can guide your diagnostic workup.
Rotator Cuff Pathology
Rotator cuff disease is the leading cause of shoulder-related disability, affecting approximately 8% of American adults 3. Patients typically present with radiating shoulder pain, especially in the posterior aspect of the shoulder and scapula, with limitations in active overhead motion 4.
Scapular Dyskinesis
This often-forgotten cause involves abnormal scapular motion (STAM - scapulothoracic abnormal motion) that can lead to compensatory glenohumeral pathology 4, 5. Patients present with radiating shoulder pain in the posterior shoulder and scapula, associated with glenohumeral pain, instability, or rotator cuff pathologies 4.
Algorithmic Approach to Workup
Initial Imaging
Start with plain radiography of the shoulder regardless of suspected etiology 6. This is the appropriate first-line imaging study.
If Radiographs Are Normal or Nonspecific:
For suspected rotator cuff pathology:
- MRI shoulder without IV contrast or ultrasound shoulder are equivalent first-line studies 6
- MRI is preferred when there is large body habitus, restricted range of motion, or suspicion of other intraarticular pathology like labral tears 6
- Ultrasound has 90-91% sensitivity and 93-95% specificity for full-thickness rotator cuff tears 6
For suspected cervical radiculopathy:
- Cervical spine imaging (MRI cervical spine) is indicated
- Consider cervical nerve root blocks for both diagnostic and therapeutic purposes 2
Critical Pitfalls to Avoid
Don't dismiss scapular pain as non-specific: It has diagnostic value and may be the earliest symptom of cervical radiculopathy, appearing weeks before arm symptoms 1
Don't assume all shoulder pain is rotator cuff disease: The prevalence of asymptomatic rotator cuff tears is 54% in patients over 60 years old 3, so imaging findings must correlate with clinical presentation
Assess pain characteristics carefully: The presence of both superficial and deep pain strongly suggests C5 or C8 radiculopathy, while deep pain alone suggests C6 or C7 involvement 2
Evaluate scapular motion: Abnormal scapular motion can be both a primary cause and a compensatory mechanism for other shoulder pathologies 4, 5
Additional Considerations
Suprascapular neuropathy is a rare but increasingly recognized cause of shoulder and scapular pain that should be considered when history, examination, and imaging don't adequately explain symptoms 7. This requires specific nerve conduction studies for diagnosis.
Winged scapula from long thoracic nerve injury presents with prominent medial scapular border protrusion and should be evident on physical examination 8.