title: [A comparative study on effect of different defect diameters on healing in middle 1/3 tibia monolayer cortical bone defect mouse model].
abstract: OBJECTIVE
  To compare the effect of different defect diameters on healing in the middle 1/3 tibia monolayer cortical bone defect mouse model so as to establish an animal model for bone tissue engineering study, mechanism study on bone defect repair, and gene therapy research.
  
  
  METHODS
  Ten 8-week-old C57BL/6J mice, weighing (20 +/- 2) g, were randomly divided into 2 groups, 5 mice in each group. The middle 1/3 tibiae monolayer cortical bone defect model of 0.8 mm (group A) or 1.0 mm (group B) in diameter was established with burr drill. At 7, 21, and 28 days after modeling, the molybdenum target X-ray radiography was used to observe the defect repair; at 28 days, Micro CT and three-dimensional imaging were used to evaluate bone defect repair, and tibia specimens were harvested for HE staining.
  
  
  RESULTS
  At 7 days after modeling, tibia fracture occurred in 5 mice in group B, no fracture in group A. X-ray films, Micro CT scan, and HE staining showed bony union in group A at 28 days. The quantitative analysis of trabecular bone by Micro CT showed that trabecular number, connectivity density, and bone volume in group A were significantly greater than those in group B (P < 0.05), mean of segmented region--mean 2 was significantly less than that in group B (P < 0.05), but no significant difference was found in trabecular separation and trabecular thickness between 2 groups (P > 0.05).
  
  
  CONCLUSIONS
  The middle 1/3 tibia monolayer cortical bone defect mouse model of 0.8 mm in diameter is the ideal animal model for study repair mechanism of tibia defect or bone tissue engineering.
authors.affiliation: Department of Orthopaedics, Research Institute of Orthopaedic Trauma of Chinese PLA, Kunming General Hospital of Chengdu Military Command, Kunming Yunnan 650032, PR China.
authors.forename: Fubing
authors.initials: F
authors.lastname: Li
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Xu
authors.forename: Xinghua
authors.initials: X
authors.lastname: Pan
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Duming
authors.initials: D
authors.lastname: Yang
authors.forename: Lun
authors.initials: L
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Sha
authors.forename: Jian
authors.initials: J
authors.lastname: Shi
authors.forename: Wanqiu
authors.initials: W
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001857:Bone Matrix / Q000293:injuries / Q000601:surgery; D001861:Bone Regeneration / Q000502:physiology*; D004195:Disease Models, Animal; D021621:Imaging, Three-Dimensional; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015203:Reproducibility of Results; D013977:Tibia / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D013978:Tibial Fractures / Q000000981:diagnostic imaging; D014945:Wound Healing; D055114:X-Ray Microtomography