Experimental and computational models to investigate the effect of adhesion on the mechanical properties of bone-cement composites

A generic finite element approach was developed to study the effect of adhesion on the mechanical response of bone cement composites and validated against literature data. The results showed that a zero friction bone-cement (PMMA) interface conditions captured the results of the experimental testing better than assuming a fully bonded interface. An experimental model for studying the effect of interface adhesion in a bone-cement like composite was also developed in the present study. The results using this model indicate that the difference in Young's modulus and ultimate strength between a fully bonded interface and unbonded interface is approximately 30% for bone volume fraction similar to what can be found in osteoporotic vertebrae. Apart from concluding that bone to cement adhesion is a major contributor to the mechanical response of bone-cement composites, our studies based on the generic FE approach also indicate that the mechanical properties of the cement is the most important contributor to the resulting mechanical properties of the composite at bone volume fraction relevant in terms of vertebroplasty treatment.