双束股骨双隧道法重建后十字韧带的实验研究

In vitro study of knee stability after double-band and double-tunnel posterior cruciate ligament reconstruction

目的研究双束股骨双隧道法重建后十字韧带(PCL)限制胫骨后移、恢复膝关节后向稳定性的能力,并与单束重建法进行比较。方法用双束股骨双隧道、单束前位点和单束后位点三种方法对膝关节标本进行后十字韧带重建。术后分别于膝关节屈曲0°、30°、60°、90°及120°时,对胫骨施行200N的后向作用力,测量胫骨相对于股骨后移的距离。结果在屈膝角度较小(0°～30°)的情况下,单束后位点重建法术后胫骨后移的距离与完整标本接近(P>0.05);但屈曲超过30°,特别是超过60°后,单束后位点重建法术后胫骨后移的距离明显大于完整标本(P<0.01)。在膝关节的整个屈曲范围(0°～120°)内,双束股骨双隧道和单束前位点重建法术后胫骨后移的距离与完整标本接近(P>0.05),在某些角度有轻微的过度限制胫骨后移的现象。结论双束股骨双隧道重建法,在膝关节的整个屈伸范围(0°～120°)内,可以有效地限制胫骨后移,恢复膝关节的后向稳定性;单束前位点重建法维持膝关节后向稳定性的能力也较强;而单束后位点重建法限制胫骨后移、恢复膝关节后向稳定性的能力最不确定。

Objective To compare the ability of three different reconstructive procedures in restricting the posterior displacement of tibia and restoring anteroposterior stability of the knee joint from 0° to 120° flexion. Methods Three posterior cruciate ligament(PCL) reconstructive procedures were performed, namely double-band and double-tunnel reconstruction, uni-band anterior tunnel(aPc) reconstruction and posterior tunnel(pPc) reconstruction. The posterior displacement of the tibia in relation to the femur was measured when 200 N posterior force was applied. Results Within the flexion range from 0° to 30°, the displacement in the pPc reconstruction showed little difference from an intact knee(P>0.05). But when the flexion exceeded 30°, especially when it exceeded 60°, the displacement in pPc increased markedly, much greater than that of an intact knee (P<0.01). In double-band and aPc reconstruction, the displacement was approximately the same as that of an intact knee ranging from 0° to 120°(P>0.05), while a slight over-restriction may be found at some angles. Conclusion Double-band reconstruction could effectively restrict the posterior displacement of the tibia and restore anteroposterior stability to the knee joint within its full range of flexion. aPc reconstruction could also maintain the posterior stability of the knee, while the result of pPc reconstruction is most unsatisfactory.