title: Numerical Simulation and Clinical Verification of the Minimally Invasive Repair of Pectus Excavatum.
abstract: OBJECTIVE
  In this article we proposed a modeling method by building an assembled model to simulate the orthopedic process of minimally invasive surgery for pectus excavatum and got the clinical verification, which aims to provide some references for clinic diagnoses, treatment, and surgery planning.
  
  
  METHODS
  The anterior chest model of a 15-year-old patient was built based on his CT images; and his finite element model and the Nuss bar were created. Coupling of nodal displacement was used to connect bones with cartilages of the anterior chest. Turning the Nuss bar over is completed by rotating displacement of it. By comparing the numerical simulation outcomes with clinical surgery results, the numerical simulation results were verified.
  
  
  RESULTS
  The orthopedic process of minimally invasive surgery of pectus excavatum was simulated by model construction and numerical analysis. The stress, displacement fields and distribution of the contact pressure between the Nuss bar and costal cartilages were analyzed. The relationship between correcting force and displacement was obtained. Compared with the of clinical results, the numerical simulation results were close to that of the actual clinical surgery in displacement field, and the final contact position of the Nuss bar and the costal cartilages.
  
  
  CONCLUSIONS
  Compared with the rigid model, the assembled simulation model is in more conformity with the actual clinical practice. The larger curvature results in the maximum equivalent stress, which is the main reason for clinical pain. Soft tissues and muscles should be taken into account in the numerical simulation process.
authors: Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin University of Technology, Tianjin, 300384, China ; School of Mechanical Engineering, Tianjin University of Technology, Tianjin,300384, China.
authors: WeiHong
authors: W
authors: Zhong
authors: Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin University of Technology, Tianjin, 300384, China ; School of Mechanical Engineering, Tianjin University of Technology, Tianjin,300384, China.
authors: JinDuo
authors: J
authors: Ye
authors: Military General Hospital of Beijing PLA, Beijing, 100026,China.
authors: JiFu
authors: J
authors: Liu
authors: Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin University of Technology, Tianjin, 300384, China ; School of Mechanical Engineering, Tianjin University of Technology, Tianjin,300384, China.
authors: ChunQiu
authors: C
authors: Zhang
authors: Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin University of Technology, Tianjin, 300384, China ; School of Mechanical Engineering, Tianjin University of Technology, Tianjin,300384, China.
authors: MeiJiao
authors: M
authors: Zhao
keywords: 3D reconstruction; Clinical verification; Numerical simulation; Pectus excavatum; Turning the Nuss bar over