Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Spine
Abstract number: 25606
CORRELATION OF VERTEBRAL STRENGTH TOPOGRAPHY WITH 3-
DIMENSIONAL COMPUTED TOMOGRAPHY STRUCTURE
Evalina BURGER, Andriy NOSHCHENKO, Vikas PATEL
University of Colorado Denver, Aurora (UNITED STATES)
Introduction: To prevent intervertebral implant subsidence, the interface between an
implant and the vertebral bone must have sufficient strength. Strength across the
endplate is not consistent. An accurate assessment of vertebrae endplate stiffness at
discrete sites before surgery could improve postoperative outcomes. Methods: In this
cadaveric study, 8 lumbar vertebrae (L5, 6; L4, 2) were tested. Stiffness was
assessed at 9 discrete sites of cranial and caudal surfaces with indentation testing
(IT). Micro-CT images were obtained before and after IT. Micro-CT characteristic of
cortical and cancellous bone were defined at 45 regions of interest with a 3dimentional
coordinate system. Osteoporotic status of the vertebrae was defined
using QCT criteria. Predictive models of the local stiffness were created using bone
structural and density characteristics. Results: Stiffness across the tested surfaces
was highly variable and was significantly decreased in osteoporotic vertebrae.
Endplate thickness and density combined with trabecular density and trabecular
number of adjacent cancellous bone were found to be good predictors of local
stiffness. Three models based on different combinations of bone structural
characteristics were created. Conclusions: The obtained results confirm the study
hypothesis that strength at discrete sites of human lumbar vertebrae depends on 3demensional
structure and density of the cortical and cancellous bone and that local
stiffness can be evaluated using models based on vertebrae bone characteristics
obtained from quantitative computed tomography images. Clinical Relevance: The
use of these predictive models in the clinical setting could improve the assessment of
risk for vertebrae fracture.
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