Lever Test: Role of Its Assistance in Diagnosis of Anterior Cruciate Ligament Injury

Background: The diagnosis of ACL tear is aided by clinical tests and imaging evaluation with MRI. The main clinical tests include Lachman, Anterior Drawer  and Pivot shift test. A newer clinical test called lever test was proposed recently with higher sensitivity compared to traditional tests. Objectives: To investigate the sensitivity, specificity and other statistical parameters of newly proposed  lever test for ACL injury along with other established tests, Lachman test, Anterior Drawer test and Pivot Shift test. Methods: 242 patients consecutive patients with a complaint of knee pain  were included in the study over a period of 4 years between ages of 18 to 50 years. They were evaluated with clinical tests Lever test, Lachman test, Anterior Drawer test and Pivot Shift test without anaesthesia and under anaesthesia. Results of diagnostic arthroscopy was taken as gold standard. Results: A total of 242 consecutive subjects were eligible during the study period, of which 182 were males while the remaining 60 were females. Compared to gold standard, without anaesthesia the lever test had a sensitivity of 85.57%, specificity of 25.00%, PPV of 82.18%, NPV of 30.00%, and accuracy of 73.55%. Similarly regarding other tests the sensitivity and specificity without anaesthesia were, Lachman test sensitivity of 93.81%, specificity of 20.83%, PPV of 82.73%, NPV of 45.45%, and accuracy of 79.34%, Anterior Drawer test sensitivity of 80.41%, specificity of 33.33%, PPV of 82.98%, NPV of 29.63%, and accuracy of 71.07%, Pivot Shift test sensitivity of 40.21%, specificity of 91.67%, PPV of 80.17%, NPV of 95.12%, and accuracy of 50.41%.  The results under anaesthesia compared to arthroscopy findings were Lever Test Lachman Anterior Drawer Pivot Shift Accuracy, % 77.69, 79.34, 71.90, 80.99 Sensitivity, % 91.75, 98.97, 93.81, 98.97, Specificity, % 20.83, 36.33, 20.83, 58.33 PPV, % 82.41, 81.36, 58.33, 87.95 NPV, % 38.46, 66.67, 39, 36.84. Conclusion:  The lever test needs to be studied extensively considering multiple variables like correlation with BMI, position of wrist, partial injuries and also interobserver variations before it gets standardized into routine examination.