Mechanisms of non-contact anterior cruciate ligament injury as determined by bone contusion location and severity

Abstract

Background: The location and severity of tibiofemoral bone contusions in magnetic resonance imaging scans in patients with acute non-contact anterior cruciate ligament injuries can reflect the primary mechanisms of anterior cruciate ligament injuries. There has been limited investigation to subdividing the bone contusion model in the medial and lateral directions of the tibial plateau and the femoral condyle. Methods: A retrospective review of 93 consecutive magnetic resonance imaging examinations of patients with acute non-contact anterior cruciate ligament injuries was conducted to identify bone contusions of the knee. The locations and the severity of the bone contusions were determined using magnetic resonance imaging scans for each anatomic site, including the lateral femoral condyle, the lateral tibial plateau, the medial femoral condyle, and the medial tibial plateau. The bone contusions in the lateral-medial and anterior-posterior directions of four anatomical sites were subdivided into six compartments. The severity of the bone contusions was graded on a scale of 1-4. The location and the severity of bone contusions were accessed in the sagittal and coronal planes on the femoral and tibial sides of the knee using the radiology information system. Results: The prevalence of bone contusions on the magnetic resonance imaging scans was as follows: 78.49% on the lateral femoral condyle, 88.17% on the lateral tibial plateau, 49.46% on the medial femoral condyle, and 69.89% on the medial tibial plateau. The most common and severe compartments of the lateral femoral condyle, the lateral tibial plateau, the medial femoral condyle, and the medial tibial plateau were the central-lateral (CL), the posterior-medial (PM), the CL, and the posterior-lateral (PL) compartments, respectively. Conclusions: The location patterns and severity of bone contusions in patients indicated that internal tibial rotation, valgus, and the anterior and lateral translation of the tibia were the primary mechanisms of non-contact anterior cruciate ligament injury.