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.