Summary

Severity of lateral compartment bone bruise was significantly related to lateral meniscus tears from non-contact ACL injury. However, medial meniscus tear was not related to severity of lateral or medial compartment bone bruise.

Abstract

Backgrounds: Bone bruise associated with anterior cruciate ligament (ACL) injury varies according to individuals when seen on magnetic resonance imaging (MRI). The relationship between bone bruise and meniscus tear remains controversial. Some researchers have reported that bone bruise volume or presence was associated with meniscus tears, however, other researchers have also reported that meniscus tears are not associated with severity of bone contusions. The purpose of this study was to evaluate the relationship between the severity of bone bruise and the presence of meniscus tears in acute ACL injury.

Materials And Methods

One-hundred-seventeen patients who were diagnosed noncontact ACL injury and underwent primary ACL reconstruction (ACLR) at our institution were retrospectively investigated. Inclusion criteria were patients who had MRI performed within 4 weeks from injury and ACLR within 8 weeks from the MRI. Exclusion criteria were past history of knee injury and unknown injury date. Demographic data including patient’s age, height, weight and body mass index (BMI) were obtained from the medical records. Bone bruise was defined as increased signal intensity on the T2 weighted image or short tau inversion recovery (STIR) sequences in MRI. Location of bone bruises was classified into four areas [medial femoral condyle (MFC), medial tibial plateau (MTP), lateral femoral condyle (LFC), lateral tibial plateau (LTP)] on MRI. Severity of bone bruise was evaluated by scoring the depth from 0 to 5 points according to the ICRS depth scale. The meniscus tear was defined as injury of lateral or medial meniscus which was identified under arthroscopy regardless of whether treatment was performed or not.
Statistical analysis was performed by using the Mann-Whitney U test with

Significance

level of 0.05.

Results

Seventy-five patients were included in this study. There were no significant differences in patient’s demographic data between the presence and absence of meniscus tear and bone bruise groups. Prevalence of bone bruise on the LFC and LTP were 80% and 76% respectively. Prevalence of bone bruise on the MFC and MTP were 2.7% and 9.3%, respectively. Prevalence of lateral meniscus tear was 61.3% and medial meniscus tear was 13.3%. The mean values of bone bruise severity on LFC and LTP in the lateral meniscus tear group were significantly higher than that in the no tear group (p = 0.037 and 0.036, respectively). The mean values of bone bruise severity on LFC in the medial meniscus tear group were higher than that in the no tear group, but there was no significant difference.

Conclusion

Severity of bone bruises on LFC and LTP was positively related to lateral meniscus tear. On the other hand, severity of bone bruises was not related to medial meniscus tears. This study has shown that lateral meniscus tears could be predicted from severe bone bruises on LFC or LTP in acute noncontact ACL injury.