title: Microstructure and biomechanical characteristics of bone substitutes for trauma and orthopaedic surgery.
abstract: BACKGROUND
  Many (artificial) bone substitute materials are currently available for use in orthopaedic trauma surgery. Objective data on their biological and biomechanical characteristics, which determine their clinical application, is mostly lacking. The aim of this study was to investigate structural and in vitro mechanical properties of nine bone substitute cements registered for use in orthopaedic trauma surgery in the Netherlands.
  
  
  METHODS
  Seven calcium phosphate cements (BoneSource®, Calcibon®, ChronOS®, Eurobone®, HydroSet™, Norian SRS®, and Ostim®), one calcium sulphate cement (MIIG® X3), and one bioactive glass cement (Cortoss®) were tested. Structural characteristics were measured by micro-CT scanning. Compression strength and stiffness were determined following unconfined compression tests.
  
  
  RESULTS
  Each bone substitute had unique characteristics. Mean total porosity ranged from 53% (Ostim®) to 0.5% (Norian SRS®). Mean pore size exceeded 100 μm only in Eurobone® and Cortoss® (162.2 ± 107.1 μm and 148.4 ± 70.6 μm, respectively). However, 230 μm pores were found in Calcibon®, Norian SRS®, HydroSet™, and MIIG® X3. Connectivity density ranged from 27/cm3 for HydroSet™ to 0.03/cm3 for Calcibon®. The ultimate compression strength was highest in Cortoss® (47.32 MPa) and lowest in Ostim® (0.24 MPa). Young's Modulus was highest in Calcibon® (790 MPa) and lowest in Ostim® (6 MPa).
  
  
  CONCLUSIONS
  The bone substitutes tested display a wide range in structural properties and compression strength, indicating that they will be suitable for different clinical indications. The data outlined here will help surgeons to select the most suitable products currently available for specific clinical indications.
authors.affiliation: Department of Surgery-Traumatology, Erasmus MC, University Medical Centre Rotterdam, PO Box 2040, 3000 CA Rotterdam, the Netherlands. e.vanlieshout@erasmusmc.nl
authors.forename: Esther M M
authors.initials: EM
authors.lastname: Van Lieshout
authors.forename: Gerdine H
authors.initials: GH
authors.lastname: Van Kralingen
authors.forename: Youssef
authors.initials: Y
authors.lastname: El-Massoudi
authors.forename: Harrie
authors.initials: H
authors.lastname: Weinans
authors.forename: Peter
authors.initials: P
authors.lastname: Patka
mesh_terms: D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000737:chemistry* / Q000592:standards; D018786:Bone Substitutes / Q000737:chemistry* / Q000592:standards*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery*; D006801:Humans; D008422:Materials Testing / Q000379:methods*; D019637:Orthopedic Procedures / Q000295:instrumentation* / Q000379:methods; D011859:Radiography; D014947:Wounds and Injuries / Q000503:physiopathology / Q000601:surgery*
chemical_list: D001843:Bone Cements; D018786:Bone Substitutes