The role of shear micromotion on bone ingrowth into a three-dimensional porous scaffold predicted by a mechanoregulatary finite element model

Area of Science:

• Biomaterials Engineering
• Orthopedic Surgery
• Computational Biology

Background:

• The mechanical environment at the bone-implant interface is crucial for successful bone ingrowth in total knee replacements.
• Understanding mechanobiology is key to optimizing scaffold design for orthopedic implants.

Purpose of the Study:

• To predict tissue formation and bone ingrowth in total knee replacement scaffolds using a mechanoregulatory model.
• To investigate the effects of scaffold porosity and mechanical loading on bone ingrowth.

Main Methods:

• Application of a computational mechanoregulatory model.
• Simulation of tissue evolution for two scaffold porosities under varying loads.
• Analysis of shear displacement and strain transmission within scaffolds.

Main Results:

• Low levels of shear displacement, when applied across the gap during compressive motion, improved bone formation by facilitating deeper strain transmission into the scaffold.
• Scaffolds with higher porosity demonstrated greater tolerance to shear micromotion.
• The compliance of higher porosity scaffolds created a mechanical environment conducive to tissue differentiation, enhancing interface stiffness.

Conclusions:

• Optimizing shear micromotion is critical for promoting bone formation in total knee replacement interfaces.
• Higher porosity scaffolds offer improved performance in total knee replacements due to their ability to manage micromotion and promote bone ingrowth.
• Scaffold design, specifically porosity, significantly influences the mechanical environment and subsequent bone ingrowth success.