title: Effect of stainless steel and titanium low-contact dynamic compression plate application on the vascularity and mechanical properties of cortical bone after fracture.
abstract: OBJECTIVE
  Comparison of the effect of stainless steel and titanium low-contact dynamic compression plate application on the vascularity and mechanical properties of cortical bone after fracture.
  
  
  METHODS
  Randomized, prospective.
  
  
  METHODS
  Orthopaedic research laboratory.
  
  
  METHODS
  Ten large (greater than twenty-five kilogram) adult dogs.
  
  
  METHODS
  A short, midshaft spiral tibial fracture was created, followed by lag screw fixation and neutralization with an eight-hole, 3.5-millimeter, low-contact dynamic compression plate (LCDCP) made of either 316L stainless steel (n = five) or commercially pure titanium (n = five). After surgery, animals were kept with unrestricted weight-bearing in individual stalls for ten weeks.
  
  
  METHODS
  Cortical bone blood flow was assessed by laser Doppler flowmetry using a standard metalshafted probe (Periflux Pf303, Perimed, Jarfalla, Sweden) applied through holes in the custom-made LCDCPs at five sites. Bone blood flow was determined at four times: (a) prefracture, (b) postfracture, (c) postplating, and (d) ten weeks postplating. After the dogs were killed, the implant was removed and both the treated tibia and contralateral tibia were tested for bending stiffness and load to failure.
  
  
  RESULTS
  Fracture creation decreased cortical perfusion in both groups at the fracture site (p = 0.02). The application of neither stainless steel nor titanium LCDCPs further decreased cortical bone blood flow after fracture creation. However, at ten weeks postplating, cortical perfusion significantly increased compared with acute postplating levels in the stainless steel (p = 0.003) and titanium (p = 0.001) groups. Cortical bone blood flow ten weeks postplating was not significantly different between the titanium group and the stainless steel group. Biomechanical tests performed on the tibiae with the plates removed did not reveal any differences in bending stiffness nor load required to cause failure between the two groups.
  
  
  CONCLUSIONS
  Both titanium and stainless steel LCDCPs were equally effective in allowing revascularization, and neither provided a significant advantage in biomechanical properties of fracture healing at ten weeks.
authors.affiliation: Orthopaedic Research Laboratory, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Jain
authors.forename: N
authors.initials: N
authors.lastname: Podworny
authors.forename: T
authors.initials: T
authors.lastname: Hearn
authors.forename: G I
authors.initials: GI
authors.lastname: Anderson
authors.forename: E H
authors.initials: EH
authors.lastname: Schemitsch
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001842:Bone and Bones / Q000098:blood supply*; D004195:Disease Models, Animal; D004285:Dogs; D004548:Elasticity; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D008422:Materials Testing; D011446:Prospective Studies; D011897:Random Allocation; D012039:Regional Blood Flow; D013193:Stainless Steel; D013978:Tibial Fractures / Q000601:surgery*; D014025:Titanium; D016474:Weight-Bearing
chemical_list: D001672:Biocompatible Materials; D013193:Stainless Steel; D014025:Titanium