Influence of Porocoat Beaded Coating Structure on Bone Ingrowth Around the Porous Coated Implant: A Two-Dimensional Finite Element Study

The long-term biomechanical functionality of uncemented orthopaedic implants relies on bone ingrowth around porous coated implants. The present study aims to numerically predict the spatial–temporal distribution of tissue differentiation around the Porocoat coated implant surface by employing the mechanoregulatory tissue differentiation algorithm using 2D Finite Element Analysis. Besides this, the influence of the porosity gradient from the substrate surface to the bone interface on bone ingrowth is also investigated. Two distinct 2D microscale models were developed and designated MODEL A and MODEL B. Both models have a three-layer beaded coating, with MODEL B incorporating the effect of a porosity gradient. Both models were assessed for bone ingrowth distribution. The percentage of bone ingrowth in the inter-bead spacing was predicted to be 66% for MODEL A and 45% for MODEL B after the attainment of equilibrium. The results of the simulation showed that a higher amount of bone ingrowth was predicted in MODEL A, which indicates a strong implant-bone interface. The presence of a porosity gradient was found to weaken the interface through reduced bone formation. The findings of the present study are well in corroboration with relevant studies which suggested that predicted results could be employed to predict bone ingrowth.