title: Computational modelling of ovine critical-sized tibial defects with implanted scaffolds and prediction of the safety of fixator removal.
abstract: Computational model geometries of tibial defects with two types of implanted tissue engineering scaffolds, β-tricalcium phosphate (β-TCP) and poly-ε-caprolactone (PCL)/β-TCP, are constructed from µ-CT scan images of the real in vivo defects. Simulations of each defect under four-point bending and under simulated in vivo axial compressive loading are performed. The mechanical stability of each defect is analysed using stress distribution analysis. The results of this analysis highlights the influence of callus volume, and both scaffold volume and stiffness, on the load-bearing abilities of these defects. Clinically-used image-based methods to predict the safety of removing external fixation are evaluated for each defect. Comparison of these measures with the results of computational analyses indicates that care must be taken in the interpretation of these measures.
authors: Biomechanics Research Centre (BMEC), Biomedical Engineering, National University of Ireland, Galway, Ireland. Electronic address: heatherdoylenuig@gmail.com.
authors: Heather
authors: H
authors: Doyle
authors: Biomechanics Research Centre (BMEC), Biomedical Engineering, National University of Ireland, Galway, Ireland.
authors: Stefan
authors: S
authors: Lohfeld
authors: Institute of Orthopaedic Research and Biomechanics Centre of Musculoskeletal Research, University of Ulm, Ulm, Germany.
authors: Lutz
authors: L
authors: Dürselen
authors: Biomechanics Research Centre (BMEC), Biomedical Engineering, National University of Ireland, Galway, Ireland.
authors: Peter
authors: P
authors: McHugh
mesh_terms: D000818:Animals; D002130:Calcium Phosphates; D019245:Compressive Strength; D003198:Computer Simulation; D004548:Elasticity; D016267:External Fixators; D020342:Finite Element Analysis; D008422:Materials Testing; D011091:Polyesters; D012449:Safety; D012756:Sheep; D013314:Stress, Mechanical; D013977:Tibia / Q000000981:diagnostic imaging / Q000293:injuries*; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D016474:Weight-Bearing; D055114:X-Ray Microtomography
chemical_list: D002130:Calcium Phosphates; D011091:Polyesters; C485817:beta-tricalcium phosphate; C016240:polycaprolactone
keywords: Critical sized defect; Defect stability; External fixator; Orthopaedic scaffold; PCL; β-tricalcium phosphate