title: The role of RANKL/RANK/OPG system in the canine model of hip periprosthetic infection osteolysis.
abstract: OBJECTIVE
  We aimed to investigate whether the RANKL/RANK/OPG system is associated with the incidence of periprosthetic osteolysis with septic loosening, and to investigate the differences of RANKL/RANK/OPG system expression in synovial fluid surrounding the normal and septic loosening hip prosthesis in canine models.
  
  
  METHODS
  Twelve healthy adult mongrel canines were divided into two groups: experimental and control. Femoral head and stem replacements were conducted on the right side in both groups. The experimental group received the bacteria fluid intra-articular injection and the other group received the same amount of saline in the same day. The synovial fluid samples were gathered at the 1st, 2nd, 4th, 8th, 12th, 16th and 19th week after the bacteria fluid intra-articular injection for enzyme-linked immunosorbent assay (ELISA), the expression of the RANKL/RANK/OPG system.
  
  
  RESULTS
  Surgery on all animals was successful. Two dogs were excluded from the analysis of the result because of a surgery infection or death. The ELISA of the synovial fluid revealed that the ratio of RANKL/OPG showed a significant upward trend (p≤0.05) with time in the test group but the ratio of RANKL/OPG in the control group changed slowly over time (p&gt;0.05). The ratio of RANKL/OPG value between the test and control group showed a significant upward trend, but had no statistical difference (p&gt;0.05) over time.
  
  
  CONCLUSIONS
  It could be concluded that the RANKL/RANK/OPG system is correlated with the incidence of periprosthetic osteolysis with septic loosening. Consequently, imbalance RANKL/RANK/OPG system was related to periprosthetic osteolysis with septic loosening.
authors.affiliation: The First Clinical Hospital of Harbin Medical University, Heilongjiang - PR China.
authors.forename: Hao-Wei
authors.initials: HW
authors.lastname: Zhang
authors.affiliation: The Fourth Clinical Hospital of Harbin Medical University, Heilongjiang - PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Peng
authors.affiliation: The First Clinical Hospital of Harbin Medical University, Heilongjiang - PR China.
authors.forename: Wen-Bo
authors.initials: WB
authors.lastname: Li
authors.affiliation: The First Clinical Hospital of Harbin Medical University, Heilongjiang - PR China.
authors.forename: Ke-Guan
authors.initials: KG
authors.lastname: Song
mesh_terms: D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D004195:Disease Models, Animal; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D006622:Hip Prosthesis / Q000382:microbiology*; D010014:Osteolysis / Q000209:etiology / Q000378:metabolism* / Q000382:microbiology; D053244:Osteoprotegerin / Q000378:metabolism*; D016459:Prosthesis-Related Infections / Q000209:etiology / Q000378:metabolism* / Q000382:microbiology; D053245:RANK Ligand / Q000378:metabolism*; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism*; D013582:Synovial Fluid
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B