The Influence of the Bone Scaffold Biodegradation Process on Bone Remodeling in Critical Size Bone Defects: A Finite...

One of the main features to consider when designing bioresorbable bone scaffolds is the degradation rate of the material. The literature focuses mostly on its influence on mechanical properties, omitting its effect on the bone remodeling process. This study aimed to evaluate the influence of changes caused by ongoing biodegradation of scaffolds on the bone remodeling process. A uniaxial compression test was numerically simulated on simplified 2D bone models with bone marrow and callus tissue containing the scaffold. A total of 35 models were analyzed, considering five porosities (30%, 40%, 50%, 60%, 70%), four materials (Ti6Al4V, PLLA, PLGA, PDGLA) with constant (without biodegradation) and variable (with biodegradation, ignored for Ti6Al4V) Young's modulus. Higher porosity of scaffolds (especially 60% and 70%) allows greater load-bearing by the newly forming tissue, relieving the scaffold. Consideration of the influence of biodegradation caused achieving a higher average Young's modulus of callus, especially in the first 20 days, accelerating bone adaptation to the implant. Ti₆Al₄V caused lower changes in average Young's modulus of callus than in the case of polymers, which is caused due to its higher stiffness. This research shows the need to consider scaffold degradation when designing and analyzing their long-term biomechanical efficiency.