title: Biomechanical characteristics of cement/gelatin mixture for prevention of cement leakage in vertebral augmentation.
abstract: OBJECTIVE
  This study evaluated whether or not the addition of gelatin micro-particles into the polymethyl methacrylate (PMMA) could reduce cement infiltration in cancellous bone of vertebra.
  
  
  METHODS
  Gelatin micro-particles were prepared in various sizes and mixed with PMMA in different densities. Dynamic viscosity of the mixture was measured by a rotational rheometer. Fresh bovine vertebral bodies were sectioned into cylindrical samples. Permeability of the mixture through the samples was tested on a mechanical test machine, and calculated using Darcy's law. The PMMA/gelatin mixture also underwent compressive and bending tests, and their structures were examined by scanning electron microscopy.
  
  
  RESULTS
  The cement/gelatin mixture increased the viscosity. Significant reduction of cement permeability in cancellous bone was determined after the addition of the micro-particles. Micro-particles of 2 % in density and 125-250 μm in size decreased the permeability by 1/3 without any significant change of the cement viscosity. The biomechanical strength was unchanged in compression but decreased by up to 20 % in bending.
  
  
  CONCLUSIONS
  Gelatin micro-particles significantly increased the cement viscosity, reduced the permeability in cancellous bone of vertebra, decreased the flexural strength, but did not affect the compressive strength. Although it suggested a manageable approach in vertebral augmentation, the outcome should be further verified on a cadaveric model or an animal model before the mixture could be used safely and effectively in the clinical treatment.
authors.affiliation: Department of Orthopedics of 1st Affiliated Hospital and Orthopedic Institute, Soochow University, Suzhou, 215007, Jiangsu, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Meng
authors.forename: Ming
authors.initials: M
authors.lastname: Qian
authors.forename: Shao-Xiang
authors.initials: SX
authors.lastname: Xia
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Luo
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000737:chemistry* / Q000493:pharmacokinetics; D002417:Cattle; D019245:Compressive Strength / Q000502:physiology; D005780:Gelatin / Q000737:chemistry* / Q000493:pharmacokinetics; D008422:Materials Testing; D008954:Models, Biological; D010316:Particle Size; D010539:Permeability; D019904:Polymethyl Methacrylate / Q000737:chemistry* / Q000493:pharmacokinetics; D011183:Postoperative Complications / Q000517:prevention & control; D013131:Spine / Q000502:physiology* / Q000601:surgery; D014783:Viscosity
chemical_list: D001843:Bone Cements; D005780:Gelatin; D019904:Polymethyl Methacrylate