前交叉韧带股骨止点致密纤维分布区的三维磁共振成像解剖学研究

Femoral dense insertion of the anterior cruciate ligament with relation to femoral tunnel placement:a 3-D magnetic resonance imaging study

目的应用三维磁共振成像(MRI)研究膝关节前交叉韧带(ACL)股骨止点致密纤维分布区的解剖特点, 以期为ACL重建股骨骨道定位提供依据。方法收集2019年6月至10月期间在北京大学第三医院运动医学科随访的20例中青年ACL重建患者术后2年健侧膝关节三维MRI数据。男10例, 女10例;年龄(34.5±7.8)岁。应用Mimics 15.01软件处理影像学数据, 得到ACL股骨止点致密纤维分布区、股骨外侧髁和其软骨的三维重建模型, 以后软骨缘顶点(ADC)、股骨外髁后皮质边界、股骨外髁前方和下方软骨缘为参照, 测量ACL股骨止点致密纤维分布区前内束、中心点和后外束的高低及前后位置。结果三维重建模型显示ACL股骨止点致密纤维分布区呈条带状, 在髁间窝外侧壁的前方接近前方和下方的软骨缘, 向后上呈条带状朝过顶点延伸, 倾斜角度为12.5°。前内束、中心点、后外束均高于ADC, 与ADC的距离分别为(4.5±0.7)、(3.5±0.8)、(2.2±0.6)mm。前内束、中心点、后外束到髁间窝外侧壁后皮质边界的距离分别为(6.9±1.2)、(11.0±1.4)、(14.9±1.8)mm, 到前方软骨缘的距离分别为(16.4±1.8)、(12.1±1.6)、(8.0±1.3)mm。结论 ACL股骨止点致密纤维分布区在髁间窝外侧壁的前方接近前方和下方的软骨缘, 向后上呈条带状朝过顶点延伸, 其前内束、中心点和后外束的三维MRI解剖学测量结果可以为ACL重建股骨骨道定位提供依据。

Objective To characterize the femoral dense insertion(FDI)of the anterior cruciate ligament(ACL)using 3D magnetic resonance imaging(MRI)so as to guide the femoral tunnel placement in ACL reconstruction.Methods The 3D MRI data of the contralateral healthy knees were collected from 20 young and middle-aged patients who had been followed up for 2 years at the Department of Sports Medicine,Peking University Third Hospital from June to October 2019 after ACL reconstruction.There were 10 males and 10 females with an age of(34.5±7.8)years.The 3D models of FDI of ACL,as well as of the lateral femoral condyle and its cartilage were reconstructed using Mimics 15.01.The heights and front and rear positions of anteromedial(AM)bundle,center,and posterolateral(PL)bundle of FDI were measured with reference to the apex of deep cartilage(ADC),the deep cortical border of the lateral condyle,and the shallow and inferior cartilage margins.Results In 3D MRI models,dense fibers of ACL femoral insertion were near the shallow and inferior cartilage margins to the shallow side,and extended obliquely deep and superior toward the over-the-top(OTP)in a band-like shape.The oblique angle was 12.5°.The AM bundle,FDI center,and PL bundle were all higher than ADC,being(4.5±0.7)mm,(3.5±0.8)mm and(2.2±0.6)mm away from ADC,respectively.The median distances to the deep cortical border of the lateral condyle and the shallow cartilage margin were(6.9±1.2)mm and(16.4±1.8)mm for the AM bundle,(11.0±1.4)and(12.1±1.6)mm for the FDI center,and(14.9±1.8)mm and(8.0±1.3)mm for the PL bundle.Conclusions Dense fibers of ACL femoral insertion are near the shallow and inferior cartilage margin to the shallow side,and extend obliquely deep and superior toward the OTP in a band-like shape.As the height and depth measurements of the FDI in 3D MRI models supplement to the anatomy of ACL femoral insertion,they could be used to guide femoral tunnel placement in ACL reconstruction.