O'Brien's Test for Shoulder Pathology
O'Brien's test is a clinical examination maneuver used to assess for labral tears in the shoulder, particularly posteroinferior labral tears, though it was originally designed to detect superior labral anterior to posterior (SLAP) lesions. The test demonstrates higher diagnostic value for posteroinferior labral tears than for other types of labral tears, including SLAP tears for which it was initially developed. 1
Test Procedure
- The patient's arm is positioned in 90 degrees of forward flexion, 10-15 degrees of adduction, and maximum internal rotation (thumb pointing downward) 2, 3
- The examiner applies a downward force to the arm while the patient resists 3, 4
- The test is then repeated with the palm supinated (thumb pointing upward) 2, 5
- A positive test occurs when pain is elicited in the first position (palm down) but diminishes or disappears in the second position (palm up) 3, 1
Diagnostic Value
- Sensitivity: 63% for general labral tears 3
- Specificity: 73% for general labral tears 3
- For posteroinferior tears specifically: 83% sensitivity and 62% specificity 1
- For SLAP tears: 65% sensitivity and 50% specificity 1
- When combined with other tests like Paxinos sign, the specificity increases to 95.8% when performed in series 2
Clinical Application
- Most effective when used in combination with other clinical tests rather than in isolation 2, 3
- All patients with posterosuperior labral tears in one study were positive on both O'Brien's test and the external rotation test with the arm in abduction position (ABER test) 5
- The test is not specific enough to be used alone for surgical decision-making 3, 4
- False positives are common in patients with other shoulder conditions, including impingement or rotator cuff tears 4
Improving Diagnostic Accuracy
- Combining O'Brien's test with Paxinos sign provides the greatest positive likelihood ratio (2.71) for AC joint pathology 2
- Clinical history is crucial - patients with posterosuperior labral tears typically have a characteristic episode of shoulder pain occurring in excessive abduction and external rotation posture 5
- When clinical suspicion is high but diagnosis remains unclear, imaging (MRI or ultrasound-guided arthrosonography) should be considered 5, 1
Common Pitfalls
- The test was originally designed for SLAP tears but actually performs better for posteroinferior labral tears 1
- Relying solely on this test for diagnosis can lead to misdiagnosis, as its sensitivity and specificity are relatively low when used in isolation 3, 4
- Physical examination alone is insufficient for definitive diagnosis of labral tears; imaging confirmation is typically required before surgical intervention 3, 4