title: A special healing pattern in stable metaphyseal fractures.
abstract: OBJECTIVE
  Metaphyseal fractures heal in a rapid fashion that is different from the bone shaft healing process. Animal studies have focused on diaphyseal fractures. We investigated the metaphyseal fracture-healing process in rabbits.
  
  
  METHODS
  60 rabbits (divided into 12 groups) underwent proximal tibial osteotomy, anatomical reduction, and fixation with screws. After surgery, the proximal tibiae were harvested at different time points for histology.
  
  
  RESULTS
  No obvious osteonecrosis or bone resorption were found 2 weeks after surgery. From day 5 to week 5, woven bone or new trabeculae formed. From week 2, remodeling into lamellar bone started and reached a peak at week 6. These 3 stages overlapped. Histomorphometry showed that the structure changed as a unimodal curve.
  
  
  CONCLUSIONS
  The healing process of metaphyseal fractures appears to differ from the commonly studied healing process in diaphyseal fractures. It is rapid, and can be divided into 4 histological stages: cellular activation and differentiation, formation of woven bone, transformation of woven bone into lamellar bone, and further remodeling.
authors.affiliation: Department of Trauma and Orthopaedics , Peking University People's Hospital, Xicheng District, Beijing , P. R. China.
authors.forename: Wen Tao
authors.initials: WT
authors.lastname: Chen
authors.forename: Da Cheng
authors.initials: da C
authors.lastname: Han
authors.forename: Pei Xun
authors.initials: PX
authors.lastname: Zhang
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.forename: Yu Hui
authors.initials: YH
authors.lastname: Kou
authors.forename: Xiao Feng
authors.initials: XF
authors.lastname: Yin
authors.forename: Bao Guo
authors.initials: BG
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000473:pathology*; D005593:Fracture Fixation, Internal; D017102:Fracture Healing; D010020:Osteonecrosis / Q000473:pathology*; D010027:Osteotomy; D011817:Rabbits; D013977:Tibia / Q000473:pathology / Q000601:surgery*; D013978:Tibial Fractures / Q000473:pathology / Q000601:surgery*