Imaging Study Of Anterior Cruciate Ligament And Femoral Condyle In Adults With Non-injured Lateral Discoid Meniscus In MRI

Objective: The morphological characteristics of anterior cruciate ligament(ACL)and femoral condyle in adult patients with intact lateral discoid meniscus were studied by MRI.Methods: 60 patients were randomly selected from January 2017 to July 2018 in sports medicine department of Peking University shenzhen hospital,including 30 patients with discoid meniscus and 30 patients with non-discoid meniscus.Adopts Siemens Spectra system on MRI through coronal and sagittal scanning and measuring the length and width of the ACL;measure the Angle of ACL and medial tibial platform(AT angel);the distance from ACL femoral check point to the lateral femoral condyle;Then we randomly selected 32 patients with discoid meniscus and30 patients without discoid meniscus who were admitted to Peking University shenzhen hospital from October 2015 to July 2018 and confirmed to have no injury under MRI.measure the angle between the epicondylar line and the tangent line of the lateral condylar subchondral bone passing through the medial epicondyle(PLCA)and the angle between the epicondylar line and the tangent line of the medial condylar subchondral bone passing through the lateral epicondyle(PMCA),and the ratio of PLCA to PMCA,comparing the two groups data of the MRI.Results: the width of ACL on the coronary surface(5.41±0.88)mm in the disk-meniscus non-injured group was significantly smaller than that in the non-disk-meniscus non-injured group(6.23±0.65)mm(P < 0.05).The other coronal and sagittal plane lengths and widths showed no significant difference.The distance(5.73±0.73)mm from the ACL insertion point to the lateral femoral condyle cartilage in the lateral discoid group was significantly smaller than that in the non-discoid group(6.43±0.49)mm,with statistically significant difference(P < 0.05).There was no statistically significant difference in the AT Angle between the lateral discoid group and the non-discoid group(P > 0.05).Discoid meniscus group on the femoral condyle and the lateral femoral condyle tangent Angle(PLCA)and femoral condyle Angle(Posterior Condylar Angle,PCA)and the lateral femoral condyle Angle and the ratio of after the discoid meniscus group,differences were statistically significant(P <0.05),while the femoral medial condyle Angle(PLCA/PMCA)are much smaller than discoid meniscus and the discoid meniscus group PMCA difference has no statistical significance(P > 0.05).Conclusion: Compared with non-discoid meniscus,adult lateral discoid meniscus has abnormal ACL morphology and hypoplasia of lateral femoral condyle in the absence of injury,suggesting that it has the ability of self-adaptation and adjustment,which makes ACL and lateral femoral condyle meet more physiological and functional needs in the anatomical environment of deformity.