Chen Yan-Fei, Lu Chao, Zhao Yong, Cheng Yong-Zhong, Qiao Feng, Hou Cheng-Zhi, Xin Ying, Liu Guang-Wei
Department of Orthopaedics, Wangjing Hospital of China Academy of Chinese Medicine, Beijing 100102, China.
Zhongguo Gu Shang. 2021 Feb 25;34(2):126-30. doi: 10.12200/j.issn.1003-0034.2021.02.006.
To study mechanism of improvement of stress concentration on patellofemoral joint by stiletto needle releasing lateral patellar retinaculum guided by the theory of Jinshugu() and based on the finite element model of knee joint. and to elucidate the biomechanical mechanism of stiletto needle releasing changing patellar trajectory and reducing patellofemoral joint pressure.
CT data of knee joint from a normal male (aged 29, heighted 171 cm, weighted 58 kg) was selected. Starting with construction of three-dimensional model of knee joint by using finite element software, the finite element model of knee joint with complete tendonand bone structures were established through several steps, such as geometric reconstruction, reverse engineering, meshing, material assignment and loading analysis. The loading condition was set as 500 N load on knee joint, and the average tensile stress of quadriceps femoris tendon was about 200 N. To simulate the release of lateral patellar retinaculum by stiletto needle at 30 and 90 position of knee flexion in finite element model separately, and to compare the improvement of stress concentration of patellofemoral joint by stiletto needle intervention under different knee flexion conditions.
The peak stress of patellofemoral joint and tibiofemoral joint decreased after stiletto needle releasing of patellofemoral lateral retinaculum compared with before intervention, which was(1) knee flexion at 30 degrees:patellar cartilage decreased by 0.498 MPa (decreased 9.06%), femoral trochlea decreased by 0.886 MPa(decreased 16.27%);(2) knee flexion at 90 degrees:patellar cartilage decreased by 0.558 MPa (decreased 8.6%), femoral trochlea decreasedby 0.607 MPa (decreased 9.94%).
Releasing lateral patellofemoral retinaculum with stiletto needle could effectively alleviate the stress concentration of patellofemoral joint and reduce local stress peak value, which it is helpful to improve patellar trajectory and make stress distribution more uniform.
基于膝关节有限元模型，以“筋束骨”理论为指导，研究针刀松解髌外侧支持带改善髌股关节应力集中的机制，阐明针刀松解改变髌骨轨迹、降低髌股关节压力的生物力学机制。
选取一名正常男性（29岁，身高171cm，体重58kg）的膝关节CT数据。利用有限元软件从构建膝关节三维模型开始，经几何重建、逆向工程、网格划分、材料赋值及加载分析等步骤，建立包含完整肌腱和骨骼结构的膝关节有限元模型。加载条件设定为膝关节承受500N载荷，股四头肌肌腱平均拉应力约为200N。在有限元模型中分别模拟膝关节屈曲30°和90°位时针刀松解髌外侧支持带，比较不同屈膝条件下针刀干预对髌股关节应力集中的改善情况。
针刀松解髌股外侧支持带后，髌股关节和胫股关节的峰值应力较干预前降低，具体为：（1）屈膝30°时：髌骨软骨降低0.498MPa（降低9.06%），股骨滑车降低0.886MPa（降低16.27%）；（2）屈膝90°时：髌骨软骨降低0.558MPa（降低8.6%），股骨滑车降低0.607MPa（降低9.94%）。
针刀松解髌股外侧支持带可有效缓解髌股关节应力集中，降低局部应力峰值，有助于改善髌骨轨迹，使应力分布更均匀。
