Wang Yan, Li Zengyong, Zhang Ming
Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China; The Hong Kong Polytechnic University Shenzhen Research Institute, Hong Kong, China.
Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China.
Med Eng Phys. 2014 Nov;36(11):1394-400. doi: 10.1016/j.medengphy.2014.03.014. Epub 2014 Apr 24.
Complications of surgeries in foot and ankle bring patients with severe sufferings. Sufficient understanding of the internal biomechanical information such as stress distribution, contact pressure, and deformation is critical to estimate the effectiveness of surgical treatments and avoid complications. Foot and ankle is an intricate and synergetic system, and localized intervention may alter the functions to the adjacent components. The aim of this study was to estimate biomechanical effects of the TMT joint fusion using comprehensive finite element (FE) analysis. A foot and ankle model consists of 28 bones, 72 ligaments, and plantar fascia with soft tissues embracing all the segments. Kinematic information and ground reaction force during gait were obtained from motion analysis. Three gait instants namely the first peak, second peak and mid-stance were simulated in a normal foot and a foot with TMT joint fusion. It was found that contact pressure on plantar foot increased by 0.42%, 19% and 37%, respectively after TMT fusion compared with normal foot walking. Navico-cuneiform and fifth meta-cuboid joints sustained 27% and 40% increase in contact pressure at second peak, implying potential risk of joint problems such as arthritis. Von Mises stress in the second metatarsal bone increased by 22% at midstance, making it susceptible to stress fracture. This study provides biomechanical information for understanding the possible consequences of TMT joint fusion.
足踝手术的并发症给患者带来巨大痛苦。充分了解内部生物力学信息，如应力分布、接触压力和变形，对于评估手术治疗效果和避免并发症至关重要。足踝是一个复杂且协同的系统，局部干预可能会改变相邻部件的功能。本研究的目的是通过全面的有限元（FE）分析来评估TMT关节融合的生物力学效应。一个足踝模型由28块骨头、72条韧带和跖腱膜组成，软组织包裹着所有节段。步态期间的运动学信息和地面反作用力通过运动分析获得。在正常足和TMT关节融合的足中模拟了三个步态瞬间，即第一个峰值、第二个峰值和中间站立期。结果发现，与正常足行走相比，TMT融合后足底接触压力分别增加了0.42%、19%和37%。舟楔关节和第五跖骰关节在第二个峰值时接触压力分别增加了27%和40%，这意味着存在关节炎等关节问题的潜在风险。第二跖骨在中间站立期的von Mises应力增加了22%，使其易发生应力性骨折。本研究为理解TMT关节融合的可能后果提供了生物力学信息。
