Critical Analysis of the Lever Test for Diagnosis of Anterior Cruciate Ligament Insufficiency.
Academic Article
Overview
abstract
PURPOSE: To critically analyze the "lever test" in detecting anterior cruciate ligament (ACL) tears and to compare its accuracy with the Lachman, anterior drawer (AD), and pivot shift tests. METHODS: From June 2014 to June 2015, 91 subjects were analyzed. Inclusion criteria were subjects aged 16 to 60 years, presenting after a knee injury with subjective swelling, or an objective effusion and an uninjured normal contralateral knee for comparison. Exclusion criteria included previous knee ligamentous reconstruction, fracture of the distal femur or proximal tibia, bilateral knee injuries, or known cruciate ligament tear. The Lachman, AD, pivot shift, and lever tests were performed in the office by 2 board-certified orthopaedic surgeons with patient awake. Examiners were blinded to the presence or absence of ACL injury. Magnetic resonance imaging was used to determine injury. Sensitivity, specificity, and accuracy were evaluated for all 4 tests. Accuracy was compared using χ-square and receiver operator curves. RESULTS: Average subject age was 28 ± 11 years (61 males, 30 females). Seventy-one (79%) had ACL tears diagnosed by magnetic resonance imaging. The sensitivity, specificity, and accuracy of the lever test were 83%, 80%, and 82%, respectively. Accuracy was not statistically different from the Lachman, AD, and pivot shift tests (P = .78, .99, .07, respectively). Subanalyses were performed based on the presence of another ligament tear, timing of injury, and the presence of a meniscus tear. Although the groups were smaller and thus underpowered, the results were reported. Neither the presence of another ligament tear nor the timing of the injury affected accuracy (P = .62 and P = .47); however, the presence of a meniscus tear decreased its accuracy (P = .003). CONCLUSIONS: The lever test showed high sensitivity, specificity, and overall accuracy in the detection of ACL tears. The accuracy of the lever test was not significantly different from the Lachman, AD, or pivot shift tests. LEVEL OF EVIDENCE: Level II, prospective comparative study.
