后交叉韧带胫骨止点与双束重建胫骨骨道定位的临床解剖学研究

The clinical anatomical research of the tibial attachment of the posterior cruciate ligament and the tibial tunnel position in double-bundle posterior cruciate figament reconstruction

目的解剖研究后交叉韧带（PCL）胫骨止点情况，确定PCL前外侧束（ALB）与后内侧束（PMB）胫骨止点的位置、形状与面积，探讨PCL双束四骨道重建中胫骨骨道定位标志与定位方法。方法30例成人膝关节标本，根据屈伸膝关节过程中纤维束紧张与松弛情况，将PCL分为ALB与PMB，并确定各束中的功能束，用多种指标测量ALB、PMB与功能束的胫骨止点，解剖寻找双束四骨道重建PCL中胫骨骨道定位标志与定位方法。结果PCL胫骨止点位于后髁间窝内，其纵轴由近内斜向远外，与胫骨干夹角平均为（16．5±1．4）°。ALB与PMB胫骨止点基本呈远近排列，ALB胫骨止点接近于菱形，平均面积为（90±20）mm^2，PMB胫骨止点近似长方形，平均面积（96±32）mm^2，二者无显著差异（P〉0．05）。ALB与PMB中均存在功能束，分别止于ALB胫骨止点的远外侧部及PMB胫骨止点的远内侧部，均接近椭圆形，面积分别为（35±12）mm^2与（36±6）mm^2，二者无显著差异（P〉0．05）。ALB功能束胫骨止点中心与PMB功能束胫骨止点中心距离为（12．7±1．9）mm^2胫骨内、外侧髁间棘及胫骨上端后方骨嵴为重要的解剖标志。结论PCL胫骨止点可以容纳两个胫骨骨道，PCL的ALB与PMB中均存在功能束，提示临床双束四骨道重建PCL时，胫骨骨道应分别定位于ALB与PMB功能束胫骨止点处。

Objectives To provide the data on the shape, sizes, and locations of the attachments of the anterolateral bundle（ALB） and posteromedial bundle（PMB） of the posterior cruciate ligament （PCL） to the tibia, and to determine the reference landmarks and the methods for tibial tunnel positioning in doublebundle PCL reconstruction using double-double tunnel. Methods Thirty cadaveric knees were used as specimens. PCLs were separated into bundles according to the PCL tension pattern during knee flexion- extension, and the functional bundle in each bundle was determined. Data were obtained to describe the size, shape, position, and center of the attachments of PCL bundles. The reference landmarks and methods for tibial tunnels positioning in double-bundle PCL reconstruction using double-double tunnel were determined. Results The PCL insertion site was situated in the posterior intercondylar fossa. The longitudinal axis of the tibial attachment of PCL proceeded from proximal medial to distal lateral, and the mean angle between them and the tibial shaft was （ 16.5 ± 1.4） °. The tibial insertion site of ALB and PMB were arranged in the proximal and distal on the whole, the tibial attachment of ALB could generally be described as rhomb in shape, and the mean area of it was （90 ± 20） mm^2 ; the tibial attachment of PMB was rectangle in shape, the mean area of it was （96 ± 32） mm^2, there was no statistic difference between the area of them（P 〉 0. 05）. There were functional bundles in both ALB and PMB persistently, which attached to the distal-lateral portion of the tibial attachment of ALB and the distal-medial portion of the tibial attachment of PMB respectively, they were both oval in shape, the mean area of them were （35 ± 12） mm^2 and （36 ± 6） mm^2 respectively, the difference between them was no statistic significant （ P 〉 0. 05 ）. The mean distance between the centres of the tibial attachments of the functional bundles of ALB and that of PMB was （12. 7 ± 1.9）mm. The medial tibial spine, lateral tibial spine and the bony ridge on the posteriorproximal tibia were the key anatomic landmarks that could be used to aid in placement of independent tibial tunnels for a 2-bundle PCL reconstruction. Conclusions The tibial attachment of the PCL is sufficiently large to allow for placement of 2 independent tunnels. There are functional bundles in both ALB and PMB persistently and the optimum position for the tibial tunnel in double-bundle PCL reconstruction using double-double tunnel should be located in the attachment sites of the functional bundles of ALB and PMB.