基于MRI完全型盘状半月板矢状位的形态分析

Morphological Analysis of Sagittal Viewing of Complete Discoid Meniscus Based on Magnetic Resonance Imaging

目的基于MRI观察完全型外侧盘状半月板(complete discoid lateral meniscus,CDLM)与正常外侧半月板矢状位的形态学差异,探索CDLM破裂的机制。方法收集2017年1月至2020年12月于南华大学附属第一医院行膝关节镜半月板手术的患者资料,选取符合纳入标准的95例99膝,其中男36例38膝,女59例61膝;年龄18~55岁,平均(45.63±6.81)岁。其中29例30膝CDLM破裂(A组),16例16膝CDLM未破裂(B组),51例53膝正常外侧半月板(C组)。分别测量半月板前后径(anteroposterior diameter,APD)以及外侧胫骨近端前后径(tibial diameter,TD),用组内相关系数(intraclass correlation coefficient,ICC)分析测量者之间的一致性,取两次测量的平均值,计算APD/TD比值,比较各组之间的差异。结果APD和TD测量的ICC值分别为0.782和0.972。A组和B组APD比较差异无统计学意义(P>0.05),但两组均小于C组(P<0.05)。A组和B组TD比较差异无统计学意义(P>0.05),但A组明显小于C组(P<0.05)。A组APD/TD比值大于B组(P<0.05),但与C组比较差异无统计学意义(P>0.05),B组APD/TD比值小于C组(P<0.05)。结论CDLM的APD及TD均较正常半月板小,CDLM破裂后APD增大。

Objective The primary objective of this study is to delineate the morphological disparities between complete lateral discoid meniscus(CDLM)and the standard lateral meniscus on sagittal magnetic resonance imaging(MRI)views.Additionally,the study aims to elucidate the underlying mechanisms leading to CDLM rupture by comparing anatomical features among ruptured,unruptured CDLM,and normal lateral meniscus cases.Methods A retrospective analysis was conducted on the records of patients who underwent knee arthroscopic meniscus surgery at The First Affiliated Hospital of University of South China from January 2017 to December 2020.A total of 99 knees from 95 patients(36 males with 38 knees and 59 females with 61 knees)fulfilling the inclusion criteria were included in the study.The patient age range was 18~55 years,with a mean age of(45.63±6.81)years.These knees were classified into three groups:30 knees(from 29 patients)with ruptured CDLM(Group A),16 knees(from 16 patients)with unruptured CDLM(Group B),and 53 knees(from 51 patients)with normal lateral meniscus(Group C).MRI scans were utilized to measure two key parameters:The anteroposterior diameter(APD)of the meniscus and the proximal anteroposterior tibia diameter(TD).The intraclass correlation coefficient(ICC)was employed to assess inter-observer reliability,and the average of two measurements was recorded for analysis.Statistical comparisons were performed among the three groups for APD,TD,and the ratio of APD to TD(APD/TD),with the intention of identifying significant differences that might elucidate the mechanisms behind CDLM rupture.Results The inter-observer reliability for measuring the APD and proximal anteroposterior TD was high,with ICC values of 0.782 and 0.972 respectively.Comparing the three groups,there was no statistically significant difference in APD between ruptured(Group A)and unruptured CDLM(Group B)(P>0.05).However,both Group A and Group B had significantly smaller APDs compared to the normal lateral meniscus group(Group C)(P<0.05).Similarly,TD did not differ significantly between Group A and Group B(P>0.05),but Group A had a lower TD than Group C(P<0.05).Notably,the APD/TD ratio was significantly higher in Group A compared to Group B(P<0.05),indicating an increase in relative APD post-rupture,while Group B had a significantly lower APD/TD ratio compared to Group C(P<0.05).Conclusion The study demonstrates that complete lateral discoid meniscus(CDLM)exhibits smaller anteroposterior(APD)and proximal tibial(TD)dimensions compared to normal lateral meniscus.Furthermore,CDLM rupture is associated with an increase in the relative APD(APD/TD ratio),suggesting morphological alterations that may contribute to its susceptibility to rupture.