髌股关节排列异常的生物力学特性变化的实验研究

目的：采用电测实验应力分析和压敏片测量技术相结合的方法，对髌股关节的运动肌群应力的变化特点、髌股关节接触面积和应力分布进行了一系列实验测试。材料与方法：采用8具人膝关节标本，保留关节囊及股四头肌机腱，髌股关节间隙内安放压敏片，肌腱上安放应力传感器，进行不同条件下的加载试验。结果：（1）股四头肌肌力对髌骨的稳定起重要作用。股内、外侧肌力不平衡（即股内侧肌肌力较弱）可使骸股关节接触压力和分布状态发生变化，使外侧髌股关节面接触压力升高。（2）在模拟髌股关节排列异常（髌骨外侧倾斜）的标本上，外侧髌股关节面接触压力及范围均明显增高，但髌骨固定在相对较小范围，使局部应力集中。（3）模拟外侧支持带松解的标本上，外侧关节接触压力和面积均有所下降，髌骨活动度增大，缓解了局部高接触压状态，但股四头肌肌力的不平衡仍影响髌骨的稳定。结论：股四头肌肌力不平衡对髌股关节接触应力和分布状态以及髌骨的位移范围均有较大影响，提示临床治疗中不应忽视对股四头肌肌力的恢复。

EXPERIMENTAL STUDY ON CHANGE OF THE BIOMECHANICAL PROPERTY IN PATELLOFEMORAL MALALIGNMENT

Objectived Using electric stress analysis and pressure measuring film techniques, to determine muscular stress changes, contact and pressure distribution over the patellofemoral joint. Materials and Methods f & human knee specimens with reserved capsule and quadriceps tendon. The pressure measuring films were put into the retropatellar space and the stress transducers were fixed on the tendons. Results f (1)the unbalanced quadriceps forces may influence the patellar stability, the normal contact and pressure distribution of the patellofemoral joint. (2)On the specimens of the experimentally produced malalignment, we found that the pressure in the lateral facet increased significantly and were limited in scope, resulting in a stress concentration.(3) After releasing of the lateral retinaculum the high contact pressure in the lateral facet decreased significantly, but the influence of quadriceps forces still remained. Conclusions attention should be paied to the rehabilitation of the quadriceps forces, especially vastus medialis.