Correlation Of MRI Quantitative Measurement Of Medial Meniscus Extrusion And Medial Meniscus Injury Pattern With Cartilage Damage

Background: The medial meniscus extrusion beyond the edge of the tibial plateau can be observed on MR images of the medial meniscus of the knee joint during injury.It is worth exploring whether the external protuberance is related to the mode of medial meniscus injury and the degree of medial interventricular cartilage injury of the knee joint.Objective: To quantitatively measure the extrusion of medial meniscus under magnetic resonance imaging,and to study the factors affecting the value of medial meniscus extrusion,and whether it is related to the injury mode of medial meniscus and the degree of cartilage injury in medial compartment.Methods: In this study,117 patients diagnosed as knee meniscus posterior horn injury by sports injury and arthroscopic surgery in AHMU were selected,and they underwent knee joint MRI scan and knee arthroscopic meniscus surgery.The meniscus extrusion value(Medial Meniscus Extrusion,MME)was measured under MRI in each patient,and the BMI of each patient,whether due to acute injury,the mode of meniscus injury confirmed by arthroscopy and the grade of cartilage injury in the medial compartment were recorded from the medical record,and the correlation between the meniscus extrusion value and the above-mentioned factors was analyzed.Results: There were 31(26.5%)acute injury patients with definite recall,86(73.5%)acute injury patients with no clear recall,56(47.9%)patients with low BMI(BMI ≤ 25)and 61 patients(52.1%)with high BMI(BMI > 25).According to the site of meniscus injury,the patients were divided into three groups: meniscus posterior body injury group(60 cases,51.2%),posterior horn injury group(37 cases,31.6%)and posterior root fracture group(20 cases,17.1%).According to the injury confirmed by arthroscopy,patients with non-medial meniscus posterior root rupture were divided into two groups:compound meniscus fracture group(n = 49)and non-compound meniscus fracture group(n = 48).There were significant differences among the above groups(p=0.001,p=0.008,p=0.000,p=0.000,p<0.05).The areas below the ROC of moderate and severe cartilage injury in medial compartment and medial meniscus posterior root tearing predicted by MME were 0.794 and 0.942,respectively.Conclusion: The size of MME reflects the presence or absence of acute trauma in the patient’s disease course,their body mass index(BMI),and pattern of medial meniscus injury,and MME has good predictive value for medial meniscus posterior root rupture,and has a moderate predictive value for medial compartment cartilage damage.