TY - JOUR
T1 - Bone mineral density and donor age are not predictive of femoral ring allograft bone mechanical strength
AU - Krishnamoorthy, Bala
AU - Bay, Brian K.
AU - Hart, Robert A.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/10
Y1 - 2014/10
N2 - While metal or plastic interbody spinal fusion devices are manufactured to appropriate mechanical standards, mechanical properties of commercially prepared structural allograft bone remain relatively unassessed. Robust models predicting compressive load to failure of structural allograft bone based on easily measured variables would be useful. Three hundred twenty seven femoral rings from 34 cadaver femora were tested to failure in axial compression. Predictive variables included age, gender, bone mineral density (BMD), position along femoral shaft, maximum/minimum wall thickness, outer/inner diameter, and area. We used support vector regression and 10-fold cross-validation to develop robust nonlinear predictive models for load to failure. Model performance was measured by the root-mean-squared-deviation (RMSD) and correlation coefficients (r). A polynomial model using all variables had RMSD=7.92, r=0.84, indicating excellent performance. A model using all variables except BMD was essentially unchanged (RMSD=8.12, r=0.83). Eliminating both age and BMD produced a model with RMSD=8.41, r=0.82, again essentially unchanged. Compressive strength of structural allograft bone can be estimated using easily measured geometric parameters, without including BMD or age. As DEXA is costly and cumbersome, and setting upper age-limits for potential donors reduces the supply, our results may prove helpful to increase the quality and availability of structural allograft.
AB - While metal or plastic interbody spinal fusion devices are manufactured to appropriate mechanical standards, mechanical properties of commercially prepared structural allograft bone remain relatively unassessed. Robust models predicting compressive load to failure of structural allograft bone based on easily measured variables would be useful. Three hundred twenty seven femoral rings from 34 cadaver femora were tested to failure in axial compression. Predictive variables included age, gender, bone mineral density (BMD), position along femoral shaft, maximum/minimum wall thickness, outer/inner diameter, and area. We used support vector regression and 10-fold cross-validation to develop robust nonlinear predictive models for load to failure. Model performance was measured by the root-mean-squared-deviation (RMSD) and correlation coefficients (r). A polynomial model using all variables had RMSD=7.92, r=0.84, indicating excellent performance. A model using all variables except BMD was essentially unchanged (RMSD=8.12, r=0.83). Eliminating both age and BMD produced a model with RMSD=8.41, r=0.82, again essentially unchanged. Compressive strength of structural allograft bone can be estimated using easily measured geometric parameters, without including BMD or age. As DEXA is costly and cumbersome, and setting upper age-limits for potential donors reduces the supply, our results may prove helpful to increase the quality and availability of structural allograft.
KW - biomechanics
KW - bone mineral density
KW - spinal fusion
KW - structural bone allograft
UR - http://www.scopus.com/inward/record.url?scp=84906275100&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84906275100&partnerID=8YFLogxK
U2 - 10.1002/jor.22679
DO - 10.1002/jor.22679
M3 - Article
C2 - 25041905
AN - SCOPUS:84906275100
SN - 0736-0266
VL - 32
SP - 1271
EP - 1276
JO - Journal of Orthopaedic Research
JF - Journal of Orthopaedic Research
IS - 10
ER -