Prediction of bone damage formation in resurfacing hip arthroplasty

Abstract

Resurfacing Hip Arthroplasty (RHA) is a hip replacement method that is widely known nowadays. However, the complication on femoral bone fracture often happens in this hip replacement method which associated with the implant positioning. The objective of this study is to predict the damage formation on the bone which resulting from the RHA pin malposition. Finite element analysis was conducted in order to predict the damage formation on the bone model based on the computed tomography (CT) image of a patient. A 3D inhomogeneous bone model was developed from a 47 year old patient with an osteoarthritis disease located on the left femur. The material used for the RHA implant model is cobalt chromium and the implant is then being inserted into the femoral bone. Straight implant position with angle 130° was selected as a reference in the analysis while another three position of varus (> 130°) and valgus (<130°) were selected and known as the pin malposition. The simulation was conducted on each of the selected angles in order to predict the damage formation towards the bone model. The damage formation obtained was from the results of elements failure which occurred after applying the load. Physiological loading of a human which focusing on the normal walking condition was selected as the loading and boundary condition in this study. The femoral bone model experienced the highest damage formation when the implant located at the varus position while reduced significantly when the implant placed at the valgus position.