Differential Diagnosis for Shoulder Pain with Positive Special Tests
This clinical presentation with multiple positive special tests—Empty Can, Speed's, Hawkins-Kennedy, and O'Brien—combined with limited active and passive range of motion strongly suggests overlapping rotator cuff pathology with possible superior labral (SLAP) involvement, requiring imaging to differentiate between rotator cuff tear, subacromial impingement syndrome, and labral pathology.
Primary Diagnostic Considerations
Rotator Cuff Pathology (Most Likely)
The combination of positive Empty Can test, Hawkins-Kennedy test, and limited active/passive range of motion is highly suggestive of rotator cuff tear or severe tendinopathy 1, 2.
Empty Can (Jobe) test: When positive, this demonstrates a positive likelihood ratio of 3.90 for subacromial impingement and rotator cuff involvement 3. The test has specificity ranging from 62% to 97% depending on the study 2, 3.
Hawkins-Kennedy test: Shows pooled sensitivity of 79% and specificity of 59% for subacromial impingement syndrome, making it more useful for ruling out pathology when negative 2. This test achieved 71% overall diagnostic accuracy in one study 4.
Limited passive range of motion: This is critical—purely passive restriction suggests either adhesive capsulitis, severe glenohumeral osteoarthritis, or massive rotator cuff tear with secondary stiffness 5. Active limitation alone would suggest rotator cuff weakness, but combined active-passive restriction indicates structural or capsular pathology 6.
Subacromial Impingement Syndrome
The positive Hawkins-Kennedy test specifically targets subacromial impingement 2, 3. However, three or more positive tests out of five standard impingement tests (Neer, Hawkins-Kennedy, painful arc, empty can, external rotation resistance) confirms subacromial impingement syndrome with an area under the curve of 0.79 3.
Superior Labral Anterior-Posterior (SLAP) Tear
The positive O'Brien test and Speed's test raise concern for SLAP lesion 1.
Speed's test: While traditionally associated with biceps tendinopathy, it can indicate SLAP pathology when combined with other positive tests 1.
O'Brien test (Active Compression): Has been studied for SLAP lesions, though diagnostic accuracy varies considerably across studies 1. The relocation test shows the best sensitivity (52%) for SLAP tears, while Yergason's test demonstrates the best specificity (95%) 1.
Important caveat: SLAP lesions typically present in younger patients with overhead activities or trauma history. The compression-rotation test has the best positive likelihood ratio (2.81) for SLAP diagnosis 1.
Adhesive Capsulitis (Frozen Shoulder)
Restricted passive range of motion is the hallmark of adhesive capsulitis 5. This condition presents with:
- Diffuse shoulder pain with global restriction of passive motion in all planes 5
- Association with diabetes mellitus and thyroid disorders 5
- The shoulder shrug sign demonstrates sensitivity >80% for stiffness-related disorders including adhesive capsulitis 1
Glenohumeral Osteoarthritis
In patients over 50 years, glenohumeral osteoarthritis presents with gradual pain and progressive loss of motion, affecting both active and passive range 5.
Diagnostic Algorithm
Step 1: Initial Imaging
Obtain shoulder radiographs immediately—this is the appropriate initial imaging study for acute shoulder pain of any etiology 6.
Step 2: Advanced Imaging Based on Radiograph Results
If radiographs are normal or nonspecific, proceed with MRI shoulder without IV contrast 6:
- MRI without contrast is the best modality for assessing rotator cuff pathology, labral tears, and cartilage abnormalities 6
- MRI demonstrates high sensitivity (90-91%) and specificity (93-95%) for full-thickness rotator cuff tears 6
- Lower sensitivity for partial-thickness tears compared to MR arthrography (which shows increased sensitivity for partial articular surface tears) 6
Alternative: Ultrasound shoulder may be appropriate if:
- Large body habitus limits MRI quality 6
- Restricted range of motion due to acute pain prevents positioning 6
- US shows similar performance to MRI for full-thickness rotator cuff tears (sensitivity 90-91%, specificity 93-95%) 6
- Conflicting evidence exists for US detection of partial-thickness tears 6
Step 3: Consider MR Arthrography
MR arthrography is indicated when detailed labral evaluation is needed 6, particularly if:
- SLAP lesion remains suspected after initial MRI
- Partial-thickness rotator cuff tears require precise characterization 6
Critical Clinical Pitfalls
Do not rely on any single physical examination test for pathognomonic diagnosis—combinations of tests provide better accuracy, though only marginally 1. The clinical examination including comprehensive history remains essential 1.
Beware of test limitations: The Hawkins-Kennedy test showed no significant area under the ROC curve in one reliability study 3, and interrater reliability for most tests ranges only from fair to moderate (kappa 0.39-0.67) 3.
Massive rotator cuff tears may require expedited surgical timeline to achieve optimal functional outcomes 6—do not delay imaging if clinical suspicion is high.
The combination of positive tests across multiple categories (impingement, rotator cuff, labral) suggests complex overlapping pathology rather than a single diagnosis 1, 5.