title: Biomechanical comparison of interspinous distraction device and facet screw fixation system on the motion of lumbar spine: a finite element analysis.
abstract: BACKGROUND
  A large amount of biomechanical and clinical evidence from previous studies suggest the efficiency of the two different posterior lumber non-fusion methods, interspinous distraction device (ISDD) and facet screw fixation system (FSS), but the biomechanical comparison of ISDD and FSS has not been thoroughly clarified.
  
  
  METHODS
  In the current study, finite element methods were used to investigate the biomechanical comparison of ISDD and FSS. The range of motion (ROM), intradiscal pressure (IDP) and the protective effects gained by maintaining disc heights were evaluated.
  
  
  RESULTS
  The ROM was similar between the two non-fusion methods under static standing, flexion and lateral bending. The FSS appeared to be more effective in resisting extension. At the implanted level L3/4, FSS displayed better results for maintaining and increasing posterior disc heights. At the L4/5 level in extension and lateral bending, FSS was better than ISDD, with comparable results observed in other motions. Comparing the posterior and lateral disc heights, FSS appeared to be more effective than ISDD. FSS also had a minor effect on the inferior adjacent segment than ISDD. FSS was more effective in reducing IDP than ISDD in extension.
  
  
  CONCLUSIONS
  Through the finite element analysis study, it can be seen that FSS demonstrates more beneficial biomechanical outcomes than does ISDD, such as being more effective in resisting extension, maintaining and increasing lumbar disc heights and reducing the inferior adjacent IDP in extension.
authors.affiliation: Department of Orthopedics, General Hospital of Shenyang Military Area Command of Chinese People's Liberation Army, Shenyang, Liaoning 110016, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
authors.affiliation: Naton Institute of Medical Technology and Beijing Medical Implant Engineering Research Center, Beijing 100094, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute of Biomedical Engineering, National YangMing University, Taibei 112, Taiwan, China.
authors.forename: Wenchuan
authors.initials: W
authors.lastname: Chen
authors.affiliation: Naton Institute of Medical Technology and Beijing Medical Implant Engineering Research Center, Beijing 100094, China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Orthopedics, General Hospital of Shenyang Military Area Command of Chinese People's Liberation Army, Shenyang, Liaoning 110016, China. Email: xiangliangbi1963@163.com.
authors.forename: Liangbi
authors.initials: L
authors.lastname: Xiang
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, the Third Military Medical University, Chongqing 400037, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
authors.forename: Chengkung
authors.initials: C
authors.lastname: Cheng
mesh_terms: D001696:Biomechanical Phenomena; D001863:Bone Screws; D020342:Finite Element Analysis; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*