膝关节后交叉韧带损伤对侧副韧带生物力学的影响

背景：目前对膝关节后交叉韧带损伤后的研究多集中于软骨、后外侧结构及关节的松弛度等方面。目的：观察后交叉韧带断裂对膝关节内、外侧副韧带生物力学的影响。方法：取12具正常成人新鲜尸体膝关节标本,在200N载荷下,测试膝关节屈曲0°,30°,60°,90°位时,内、外侧副韧带中点的应变,后将12具标本的后交叉韧带全部切断再进行相同的测试。结果与结论：膝屈曲0°和30°位时,后交叉韧带断裂前后内、外侧副韧带中点的应变均为压应变,且差异无显著性意义（P〉0.05）;膝屈曲30°~90°位时,内侧副韧带中点的应变随着角度增加而逐渐增大;膝屈曲60°和90°位时,后交叉韧带断裂后拉应变较断裂前明显增大（P〈0.05）,其中内侧副韧带中点的应变均为拉应变,而外侧副韧带中点的应变在后交叉韧带完整情况下膝屈曲60°时为压应变。说明后交叉韧带完全断裂对30°内的膝关节运动无明显影响,但是随着屈曲角度的增加,内、外侧副韧带受到的影响逐渐增大。

Biomechanical effect of posterior cruciate ligament rupture on the collateral ligaments

BACKGROUND：At present, most studies on posterior cruciate ligament （PCL） rupture focus on cartilage and posterolateral structures as well as knee joint laxity. OBJECTIVE： To observe the biomechanical effects of posterior cruciate ligament （PCL） rupture on medial （MCL） and lateral collateral ligament （LCL）. METHODS：The strain in the MCL and LCL of 12 knees from young cadavers was measured at different angles （0°, 30°, 60°and 90°） under 200 N loading. The PCL of all knees was resected for the same measurements. RESULTS AND CONCLUSION：At the angles of 30°-90°, the strains of PCL intact group and PCL injury group increased as the angle increased. Under 200 N loading after PCL rupture, at the angles of 0° and 30°, the strains of MCL midpoint were not significantly increased （P 0.05）, while at the angles of 60° and 90° , the strains were significantly increased （P 0.05）. At the angels of 0° and 30°, the strains of LCL midpoint of PCL rupture knee were still compressive and not significantly increased （P 0.05） compared with the normal knee. However, at the angels of 60° and 90°, the strains were significantly increased after PCL rupture （P 0.05）. These findings suggest that the complete rupture of PCL does not produce effects on knee joint movement at the angle of 30°, but the effects on MCL and LCL were increased with increased angles.