Bone Bruise Distribution Patterns After Acute Anterior Cruciate Ligament Ruptures: Implications for the Injury Mechanism

Abstract

Background: Bone bruises observed on magnetic resonance imaging (MRI) after an anterior cruciate ligament (ACL) injury could provide significant information about ACL injury mechanisms. Purpose/Hypothesis: The purpose of this study was to investigate common bone bruise patterns after an ACL injury. It was hypothesized that the most common bone bruise distribution pattern would be only the lateral side of both the femur and tibia. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee MRI scans of patients who underwent acute ACL reconstruction from August 2016 to August 2018 at our institution were selected. Imaging sequences in the sagittal and coronal planes were used for determining the bone bruise location in the lateral-medial and anterior-posterior directions, respectively. The presence, location, and intensity of bone bruises within specific compartments of the tibia and femur were documented. The relative bone bruise patterns of the tibia and femur were classified and analyzed. Results: A total of 207 patients (165 men, 42 women) met the inclusion criteria from a total of 4209 ACL reconstruction cases. The most common relative bone bruise pattern was located on only the lateral side of both the femur and the tibia (44.4%), followed by the lateral and medial sides of both the femur and tibia (29.0%). For the pattern found on the lateral and medial sides of both the femur and tibia, the bone bruises on only the lateral side of both the tibia and femur were more severe ( P < .001 and P < .001, respectively) and more anterior ( P < .001 and P < .001, respectively) than those on only the medial side. Conclusion: The most common relative bone bruise pattern observed was on only the lateral side of both the tibia and femur. Bone bruises on the lateral side were more severe than those on the medial side in patients with bone bruises on the lateral and medial sides of both the femur and tibia. Anterior translation of the tibia relative to the femur occurred during an ACL injury based on the location of bone bruises in the anterior-posterior direction.

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

“…We found that kissing contusions occurred more commonly in the posterior aspect of the tibial plateau and the femoral condyle's central aspect. Consistent with previous studies (2,17), lateral femoral condyle's most common pattern in patients with LKCs was the centrallateral. Previous studies have reported that tibial bone contusions occur in the posterior section.…”

“…The severity and the location patterns of tibiofemoral bone contusions observed on the magnetic resonance imaging scans may result from joint impact at the time of anterior cruciate ligament injury and could provide important information about anterior cruciate ligament injury mechanisms (6,17,20,21). Previous studies have investigated the mechanisms of anterior cruciate ligament injuries using patterns of kissing bone contusions.…”

“…As bone contusions were more serious on the lateral section, the valgus was considered the primary injury mechanism (6). Other studies have reported that an anterior translation of the tibia relative to the femur with a small knee flexion angle may be the primary mechanism of an anterior cruciate ligament injury based on the observed bone contusions on the posterior tibia and anterior femur (2,17). Further, the effects of the lateral translation of the tibia on anterior cruciate ligament injury has gradually attracted attention (24,25).…”

“…It has been suggested that bone contusions observed on magnetic resonance imaging scans in the tibia and femur are secondary signs for detecting other associated abnormalities and the mechanisms of injury (13)(14)(15)(16). The degree of bone contusions may relate to the amount of energy imparted on the knee during the injury (6,17). Comprehensive investigations into the precise location and severity of the bone contusions may increase understanding of anterior cruciate ligament injury mechanisms and assist in the development of more appropriate and effective preventative measures.…”

“…Kissing contusions are defined as relative bone contusion patterns in the tibia and femur and have been the focus of research into anterior cruciate ligament injury mechanisms (18). A recent study on the location of bone contusions in the anterior-posterior direction found that the anterior translation of the tibia relative to the femur occurs during anterior cruciate ligament injury (17). In addition, the lateral femoral condyle and lateral tibial plateau were found to be more common in patients with non-contact anterior cruciate ligament injuries than those with contact injuries (6).…”