前交叉韧带股骨后外束足迹解剖变异与双束重建骨道定位的对策

目的:研究前交叉韧带(ACL)股骨侧后外侧束(PLB)在股骨足迹的解剖变异范围、参考标记和关节镜下定位方法。方法:采用30侧人膝关节标本,解剖ACL的PLB在股骨髁间窝外侧壁(Lateral Intercondylar Wall,LIW)的足迹。观察髁间窝外侧壁的形态、住院医师脊(Resident Ridge)与ACL足迹关系、测量ACL长轴与股骨干夹角(AA)、PLB中心距离髁间窝外侧壁下缘软骨的垂直高度(PD)。采用数字影像学方法对足迹进行图像分析。结果:(1)住院医师脊为ACL足迹的上界(屈膝90°),紧靠住院医师脊下方为ACL纤维最集中的部位。(2)AA=18.7±15.25°,范围在-18°与56°之间;PD=7.02±1.47mm,范围在11 mm与3.75 mm之间,二者组数据离散程度均较大。(3)髁间窝外侧壁有2种类型,梯形8侧,三角形22侧,两种髁ACL的AA、PD均有明显差异(P=0.00)。结论:(1)AA、PD因人而异,数值差异较大,必须在术中测量进行个体化PLB定位。(2)虽然由于个体化的解剖变异,关节镜下难以采用通用的指引,但新鲜损伤,可根据明确的残端足迹术中定位;陈旧损伤住院医师脊可见时,PLB中心位置可参考在住院医师脊下方、前内束骨道前方予以定位;另外,3D-CT显示的髁间窝外侧壁形态也可以作为参考,梯形者PLB中心点较高、AA角较平,三角形者PLB中心点较低、AA角较倾斜。(3)如陈旧损伤住院医师脊无法辨认,难以明确PLB高度和AA角,建议进行双束个体化原位解剖重建时需谨慎。

The Femoral Footprint Variation of the Posterolateral Bundle of ACL

Purpose The purpose of this study was to observe the variation range of femoral footprint of ACL posterolateral bundle(PLB).Methods The femoral insertions of the anteromedial bundle and PLB of the ACL were dissected from 30 male cadaveric knees.The ACL footprint on lateral intercondylar wall(LIW),shape of LIW,resident ridge,angle between ACL long axis and femoral axis(AA),vertical distance from the center of PLB to the lowest cartilage border of the LIW(PD),the distances between the center of the PLB femoral footprint and the shallow,and the deep articular cartilage borders of the lateral wall of the intercondylar notch were measured and documented on the digital photographs,then quantified with a digital image analysis system.Results(1)Angle AA was 18.7° ±15.25°(-18° to 56°),and PD was 7.02±1.47 mm(3.75 mm to 11 mm).(2)There were 2 types of LIW: trapezoidal(8 knees) and triangular(22 knees).Both AA and PD value showed significant differences between the two types of LIWs(P = 0.00).Conclusion AA and PD varied significantly from case to case,and thus footprint of PLB should be measured individually during surgery.