胫骨远端关节面力线异常对胫距关节及足底接触影响的生物力学研究

Distal tibial articular (DTA) varus or valgus deformity might cause early development of osteoarthritis of tibiotalar joint (TTJ), and also relative with unmoral plantar pressure distribution. The key and difficult point to understand the force conduction mechanism of foot and ankle joint of different DTA varus or valgus deformity, and clear the operation indications and requirements, is to clarify the influence of different degree of deformities on the TTJ contact and plantar pressure distribution. Based on the relative preliminary biomechanical studies, we will: ①produce the different degree of DTA varus and valgus deformity models with use of normal adult fresh cadaveric calf-foot specimens, and the models will be validated with use of digital speckle correlation methods; and ② used Tek-Scan system to measure and analysis the contact area, pressure distribution, peak stress, stress center and its displacement of TTJ on normal and different degree of DTA varus and valgus deformity models; and ③ the F-Scan system will be used to measure and analysis the plantar pressure distribution, and peak stress, and stress center and its displacement; and ④ a three-dimensional finite element foot-ankle model of normal and different degree of DTA varus and valgus deformities, which composed all bone segments and ligaments and joint, will be established to evaluate the biomechanical studies. According to current research, we will clarify the tibiotalar joint contact and plantar pressure distribution condition during different degree of DTA angular deformities from the point of view of the basic research. And clear the operative correction indications and operation demands. And, provide the basic research evidences and theoretical basis for the clinical rational treatment of these deformities.

胫骨远端关节面（DTA）内/外翻畸形是胫距关节（TTJ）骨关节炎的促发因素，还可致足底异常受力。明确不同畸形程度对TTJ接触情况和足底压力分布的影响，是了解足踝部异常力学传导机制和明确防治要求的关键和难点。在前期相关正常研究的基础上：①构建不同程度DTA内/外翻模型，通过数字散斑相关法验证模型的准确性和一致性；②通过Tek-Scan关节压敏片法，测量分析正常及不同程度DTA内/外翻畸形对TTJ接触面积、压力分布、峰值压强、受力中心及位移等指标的影响；③通过F-Scan足底压力分析法，测量正常及不同畸形程度对足底压力分布、峰值压强、受力中心及位移的影响；④构建正常和DTA内/外翻的足踝部三维有限元模型，模拟相关生物力学研究，并比较分析。从基础研究角度阐明不同程度DTA内/外翻畸形对TTJ接触情况和足底压力分布的影响，明确此类畸形的矫形指证和要求，为临床合理治疗提供研究基础和理论依据。

项目的背景：胫骨远端关节面（DTA）内/外翻畸形是胫距关节（TTJ）骨关节炎的促发因素，还可致足底异常受力。明确不同畸形程度对TTJ接触情况和足底压力分布的影响，是了解足踝部异常力学传导机制和明确防治要求的关键和难点。主要研究内容：在前期相关生物力学研究的基础上：①构建不同程度DTA内/外翻模型，通过数字散斑相关法验证模型的准确性和一致性；②通过Tek-Scan关节压敏片法，测量分析正常及不同程度DTA内/外翻畸形对TTJ接触面积、压力分布、峰值压强、受力中心及位移等指标的影响；③构建正常和DTA内/外翻的足踝部三维有限元模型，模拟相关生物力学研究，并比较分析。重要结果：在保留腓骨时，五种工况间关节接触面积、接触压强及峰值压强无显著差异。在内翻模型中，胫距关节受力中心向前外侧移位；在外翻模型中，受力中心向后内侧移位。在截断腓骨时，关节接触面积及峰值压强在10°内翻位和10°外翻位较中立位出现显著减小（P＜0.01）；关节接触压强在10°内翻位（P=0.01）和5°外翻位（P=0.03）较中立位出现显著增加。在内翻模型中，胫距关节受力中心向后内侧移位；在外翻模型中，受力中心向前外侧移位。关键数据及其科学意义：从基础研究角度阐明不同程度DTA内/外翻畸形对TTJ接触情况的影响，明确此类畸形的矫形指证和要求，为临床合理矫治形提供研究基础和理论依据。