title: A standardized critical size defect model in normal and osteoporotic rats to evaluate bone tissue engineered constructs.
abstract: Tissue engineered constructs should be tested for their efficacy not only in normal but also in osteoporotic bone. The rat is an established animal model for osteoporosis and is used often for bone healing studies. In this study a defined and standardized critical size defect model in the rat suitable for screening new tissue engineered constructs in normal and osteoporotic bone is described and validated. Normal and ovariectomised Wistar rats received a unilateral middiaphyseal 5 mm defect in the femur, which was instrumented with a radiolucent PEEK plate fixed with angular stable titanium screws and left untreated. All animals were euthanized eight weeks after defect surgery and the bone healing was evaluated using radiographs, computed tomography measurements, and histology. The developed fixation system provided good stability, even in osteoporotic bone. The implants and ancillary instruments ensured consistent and facile placement of the PEEK plates. The untreated defects did not heal without intervention making the model a well-defined and standardized critical size defect model highly useful for evaluating tissue engineered solutions in normal and osteoporotic bone.
authors.affiliation: AO Research Institute Davos, Clavadelerstraß 8, 7270 Davos Platz, Switzerland.
authors.forename: Livia
authors.initials: L
authors.lastname: Poser
authors.affiliation: AO Research Institute Davos, Clavadelerstraß 8, 7270 Davos Platz, Switzerland ; RISystem AG, Talstraße 2A, 7270 Davos, Switzerland.
authors.forename: Romano
authors.initials: R
authors.lastname: Matthys
authors.affiliation: Vetsuisse Faculty, University of Bern, Länggassstraße 128, 3001 Bern, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Schawalder
authors.affiliation: AO Research Institute Davos, Clavadelerstraß 8, 7270 Davos Platz, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Pearce
authors.affiliation: AO Research Institute Davos, Clavadelerstraß 8, 7270 Davos Platz, Switzerland.
authors.forename: Mauro
authors.initials: M
authors.lastname: Alini
authors.affiliation: AO Research Institute Davos, Clavadelerstraß 8, 7270 Davos Platz, Switzerland.
authors.forename: Stephan
authors.identifier: 0000-0002-8155-4202
authors.initials: S
authors.lastname: Zeiter
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology*; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
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