What does difficulty with the crossover test indicate for a shoulder injury?

Difficulty with Crossover Test Indicates Superior Labral Tear in Shoulder Injury

Difficulty with the crossover test primarily indicates a superior labral anterior posterior (SLAP) lesion or tear in the shoulder. This specific physical examination test is designed to identify injuries to the superior labrum of the shoulder joint.

Understanding the Crossover Test

The crossover test (also known as the active compression test or O'Brien's test) is one of several clinical tests used to diagnose superior labral tears. When performing this test:

• The patient experiences pain at the posterosuperior aspect of the shoulder
• The pain is typically relieved or diminished when the test position is modified
• The test has moderate diagnostic value with sensitivity of 54%, specificity of 60%, and accuracy of 57% 1

Diagnostic Value and Alternatives

The crossover test should be considered alongside other specialized tests for superior labral injuries:

• Forced Abduction Test: Shows comparable effectiveness with sensitivity, specificity, and accuracy all at 67% 2
• Crank Test: Demonstrates sensitivity of 58%, specificity of 72%, and accuracy of 66% 2
• Resisted Supination External Rotation Test: Has the highest diagnostic accuracy (82.5%) with sensitivity of 82.8% and specificity of 81.8% 3

Imaging Confirmation

When a superior labral tear is suspected based on physical examination:

1. Plain radiographs should be obtained first as the initial imaging modality to rule out fractures and other bony abnormalities 1

2. MR arthrography is the gold standard for confirming labral tears, especially in patients under 35 years of age, with sensitivity of 86-100% 1

3. Standard MRI without contrast is a highly effective alternative when optimized imaging equipment is available 1

4. CT arthrography can be considered if MRI is contraindicated 1

5. Ultrasound has limited usefulness for labral tears but can evaluate associated rotator cuff and biceps tendon pathology 4, 1

Clinical Implications

A positive crossover test has important clinical implications:

• Indicates the need for advanced imaging, particularly MR arthrography
• May necessitate surgical consultation, especially for:
  • Patients under 30 years of age
  • Those participating in high-demand or contact sports
  • Cases with significant associated lesions (Hill-Sachs or Bankart tears)
  • Patients who fail to improve after 3 months of rehabilitation 1

Potential Diagnostic Pitfalls

Neck-Shoulder Crossover

Be aware that approximately 1 in 25 patients with presumed shoulder problems may actually have neck pathology (3.6% of shoulder clinic patients have significant spine pathology) 5. This "neck-shoulder crossover" can lead to misdiagnosis if not carefully evaluated.

Test Limitations

Physical examination tests for shoulder disorders have inherent limitations:

• No single test is 100% accurate
• Combining multiple tests improves diagnostic accuracy
• Clinical correlation with imaging is essential for definitive diagnosis 6

When a patient presents with difficulty during the crossover test, the clinician should maintain a high index of suspicion for a superior labral tear while also considering the possibility of other shoulder pathologies or referred pain from cervical spine disorders.