Latest research findings on the reliability and accuracy of clinical tests to diagnose an ACL tear

Q: With regards to the tests for ACL tear, which is most reliable and/or accurate?

A: The 3 main clinical tests that are usually performed by therapists to diagnose an ACL tear include the Anterior Drawer test, Lachman test and Pivot Shift test. However the reliability and accuracy of these tests have been questioned. Here are the findings from three studies (Ostrowski 2006; Benjaminse et al 2006; Peeler et al 2010) regarding the reliability and accuracy of these tests.

1. In a study by Ostrowski (2006), they found that:

• Pivot Shift test: best for ruling IN an ACL rupture
• Lachman test: best for ruling OUT an ACL rupture
• Anterior Drawer test: inconclusive either way

2. In another meta-analysis by Benjaminse et al (2006), they found that:

• Pivot Shift test: high specificity (98%) in both acute and chronic conditions, but poor sensitivity (24%)
• Lachman test: most valid; 85% sensitivity and 94% specificity 
• Anterior Drawer test: good sensitivity (92%) and specificity (91%) in chronic conditions, but not in acute conditions 

3. In a recent study by Peeler et al (2010), they found that:

• Reliability: 
• Moderate levels of interrater reliability for all tests (anterior drawer 57%, Lachman 45%, pivot shift 53%) 
• High variation observed between clinician's scoring for each assessment technique
• Accuracy: 
• Lachman test: highest level of sensitivity when administered by orthopaedic surgeons (86%), 
• Sensitivity varied among clinician groups and by assessment technique (15%-87%)
• Conclusions: 
• Levels of accuracy and reliability for clinical examination of the ACL within a multidisciplinary sports medicine setting may be much lower than previously reported within the literature

Definitions - NB:

• Sensitivity = no. of patients with the condition who had a positive test result (ie. high sensitivity for a positive test confirms the presence of the condition)
• Specificity = no. of patients without the condition who had a negative test result (ie. high specificity for a negative test confirms the absence of the condition)

Conclusion:

Both Pivot Shift test and Lachman test appear to be more accurate in diagnosing an ACL tear than the Anterior Drawer test. However, the reliability of these tests have been shown to be only moderate.

References:

1. Ostrowski (2006) Accuracy of 3 diagnostic tests for anterior cruciate ligament tears. Journal of Athletic Training 41(1): 120-121.

2. Benjaminse, Gokeler and van der Schans (2006) Clinical diagnosis of an anterior cruciate ligament rupture: a meta-analysis. Journal of Orthopaedic & Sports Physical Therapy 36(5): 267-288.

3. Peeler, Leiter and MacDonald (2010) Accuracy and reliability of anterior cruciate ligament clinical examination in a multidisciplinary sports medicine setting. Clinical Journal of Sport Medicine 20(2): 80-85.