Translation of biomechanical concepts in bone tissue engineering: from animal study to revision knee arthroplasty

Bone defects in revision knee arthroplasty (RKA) are often located in load-bearing regions. The goal of this study was to determine if a physiologic load could be used as an in situ osteogenic signal to the scaffolds filling the bone defects. In order to answer this question, we proposed a novel translation procedure having four steps: 1) Determining the mechanical stimulus using FEM, 2) Designing an animal study to measure bone formation spatially and temporally using micro-CT imaging in the scaffold subjected to the estimated mechanical stimulus, 3) Identifying bone formation parameters for the loaded and non-loaded cases appearing in a recently developed mathematical model for bone formation in scaffold, and 4) Estimation of stiffness and the bone formation in the bone-scaffold construct. With this procedure, we estimated that after three years mechanical stimulation increases the bone volume fraction and the stiffness of scaffold by 1.5-fold, and 2.7-fold, respectively.