A modified anterior drawer test for anterior cruciate ligament ruptures

Abstract Objective This study was aimed to utilize a modified anterior drawer test (MADT) to detect the anterior cruciate ligament (ACL) ruptures and investigate its accuracy compares with three traditional tests. Methods Four hundred patients were prospectively enrolled between January 2015 and September 2017 preoperatively to undergo knee arthroscopic surgeries. The MADT, anterior drawer test, Lachman test, and pivot shift test were used in the outpatient clinical setting and were compared statistically for their accuracy in terms of ACL ruptures, with arthroscopic findings as the gold standard. Results The prevalence of ACL ruptures in this study was 37.0%. The MADT demonstrated the highest sensitivity (0.89) and accuracy (0.92) among the four tests and had comparable specificity (0.94) and a positive predictive value (0.90) compared with the anterior drawer test, Lachman test, and pivot shift test. The diagnostic odds ratio (DOR) of MADT was 122.92, with other test values of no more than 55.45. The area under the receiver operating characteristic curve (AUC) for the MADT was 0.92 ± 0.01, with a significant difference compared with that for the anterior drawer test (z= 17.00,p< 0.001), Lachman test (z= 9.66,p= 0.002), and pivot shift test (z = 16.39,p< 0.001). The interobserver reproducibility of the MADT was good, with a kappa coefficient of 0.86. When diagnosing partial tears of ACL, the MADT was significantly more sensitive than the anterior drawer test (p< 0.001), Lachman test (p= 0.026), and pivot shift test (p= 0.013). The MADT showed similar sensitivity in detecting anteromedial and posterolateral bundle tears (p= 0.113) and no difference in diagnosing acute and chronic ACL ruptures (χ2= 1.682,p= 0.195). Conclusions The MADT is also an alternative diagnostic test to detect ACL tear, which is equally superior to the anterior drawer test, Lachman test, and pivot shifting test. It could improve the diagnosis of ACL ruptures combined with other clinical information including injury history, clinical examination, and radiological findings. Levels of evidence Level II/observational diagnostic studies Trial registration Chinese Clinical Trial Registry. ChiCTR1900022945 /retrospectively registered