Bone bruise distribution predicts anterior cruciate ligament tear location in non-contact injuries

PurposeIt is unclear whether different injury mechanisms lead to divergent anterior cruciate ligament (ACL) tear locations. This study aims to analyse the relationship between bone bruise (BB) distribution or depth and ACL tear location. MethodsA retrospective analysis of 446 consecutive patients with acute non-contact ACL injury was performed. Only patients with complete ACL tears verified during subsequent arthroscopy were included. Magnetic resonance imaging (MRI) was used to classify BB location, BB depth, ACL tear location and concomitant injuries (medial/lateral meniscus and medial/lateral collateral ligament). Demographic characteristics included age, gender, body mass index (BMI), type of sport and time between injury and MRI. Multiple linear regression analysis was used to identify independent predictors of ACL tear location. ResultsOne hundred and fifty-eight skeletally mature patients met the inclusion criteria. The presence of BB in the lateral tibial plateau was associated with a more distal ACL tear location (beta = -0.27, p < 0.001). Less BB depth in the lateral femoral condyle showed a tendency towards more proximal ACL tears (beta = -0.14; p = 0.054). Older age predicted a more proximal ACL tear location (beta = 0.31, p < 0.001). No significant relationship was found between ACL tear location and gender, BMI, type of sport, concomitant injuries and time between injury and MRI. ConclusionACL tear location after an acute non-contact injury is associated with distinct patterns of BB distribution, particularly involving the lateral compartment, indicating that different injury mechanisms may lead to different ACL tear locations. Level of EvidenceLevel III.