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[目的]利用多角度静态核磁共振扫描图像重建在体髌股关节准动态三维运动模型,并以此动态模型计算屈伸膝过程中的髌骨运动轨迹、髌股关节旋转轴.[方法]选择1名健康成年男性,对其右膝关节分别在0°、30°、60°、90°、120°5个屈膝角度进行核磁共振扫描,将扫描结果以Dicom格式导入Mimics软件中,提取髌骨、股骨轮廓,重建五个屈膝角度的静态髌股关节三维模型,再将五个静态模型导入逆向工程软件Rapidform中进行同一坐标系的配准,利用三次样条插值算法,将离散静态模型配准为动态三维运动模型;并据此动态三维模型计算髌骨运动轨迹和髌股关节旋转轴.[结果]基于静态核磁共振图像可以快速构建准确而无辐射的髌股关节准动态三维运动模型,以此动态模型计算出的髌骨运动轨迹和髌股关节旋转轴与既往文献结果相一致.[结论]在屈膝过程中,髌骨随着屈膝角度的增加相对于股骨滑车不断俯屈,同时轻度的外倾和外旋,而髌股关节旋转轴波动在殷骨通髁线附近.“,”[Objective] To reconstruct the three-dimensional quasi-dynamic motion model of the patellofemoral joint using the images of multi-angle static MRI,and to calculate the patellar trajectory and rotational axis of the patellofemoral joint during flexion and extension of the knees based on this dynamic model.[Method] A healthy adult male subject was selected,and MRI was performed for his right knee at knee flexion angles of 0°,30°,60°,90°,and 120°.The results in Dicom format were imported into Mimics software to extract the contours of the patella and femur.The three-dimensional static models of patellofemoral joint at five knee flexion angles werereconstructed and imported into the inverse engineering software Rapidform for registration of the same coordinate system.The discrete static models were registered to three-dimensional dynamic motion model using the three-spline interpolation algorithm.The patellar trajectory and rotational axis of the patellofemoral joint were calculated based on this three-dimensional dynamic model.[Result] An accurate three-dimensional quasi-dynamic motion model of the patellofemoral joint was reconstructed rapidly,and the patellar trajectory and rotational axis of the patellofemoral joint calculated based on this model were consistent with the results reported in published articles.[Conclusion] This method successfully establishes the complete motion process of the patellofemoral joint at knee flexion angles of 0°,30°,60°,90°,and 120°.During knee flexion,with the increasing flexion angle,the patella keeps flexing relative to the femoral trochlea with mild extroversion and extorsion,and the rotational axis of the patellofemoral joint fluctuates near the femoral transepicondylar axis.