Prediction of Bone Mineral Density (BMD) Adaptation in Pelvis-Femur Model with Hip Arthroplasties.

Abdul Halim Abdullah,Mitsugu Todo

doi:10.3390/jfb12030049

Abstract

The prediction of bone remodeling behaviour is a challenging factor in encouraging the long-term stability of hip arthroplasties. The presence of femoral components modifies the biomechanical environment of the bone and alters the bone growth process. Issues of bone loss and gait instability on both limbs are associated with the remodeling process. In this study, finite element analysis with an adaptive bone remodeling algorithm was used to predict the changes in bone mineral density following total hip and resurfacing hip arthroplasty. A three-dimensional model of the pelvis–femur was constructed from computed tomography (CT-based) images of a 79-year-old female patient with hip osteoarthritis. The prosthesis stem of the total hip arthroplasty was modelled with a titanium alloy material, while the femoral head had alumina properties. Meanwhile, resurfacing of the hip implant was completed with a cobalt-chromium material. Contact between the components and bone was designed to be perfectly bonded at the interface. Results indicate that the bone mineral density was modified over five years on all models, including hip osteoarthritis. The changes of BMD were predicted as being high between year zero and year one, especially in the proximal region. Changes were observed to be minimal in the following years. The bone remodeling process was also predicted for the non-operated femur. However, the adaptation was lower compared to the operated limbs. The reduction in bone mineral density suggested the bone loss phenomenon after a few years.

Highlights

Bone remodeling effects are a significant issue in promoting the long-term stability of hip arthroplasties
The stage of year 1 indicates the changes in bone mineral density (BMD) during the early phase, year 5 suggests the in final condition after
The findings suggested that a stiffer implant in the operated femur had affected the process in the non-operated femur instead of just the operated femur, especially the remodeling process in the non-operated femur instead of just the operated femur,in espeproximal region

Summary

Introduction

Bone remodeling effects are a significant issue in promoting the long-term stability of hip arthroplasties. Prediction of the bone remodeling mechanism helps to understand and encourage long-term performance. Due to arthritis and arthroplasty, bones modify their architecture and mass to adapt to the new mechanical environment [2]. The presence of the femoral component in hip arthroplasty creates a mismatch material inside the bones. The stiffer materials of the element dominate the mass load and contribute to the stress shielding problems. The decrease in mechanical load triggers the remodeling process to modify the bone mass and geometry [2,3]. The development of the quantitative bone remodeling simulation method has encouraged advanced studies in predicting the influence of the femoral component [4] and implant material properties [5]

Results

Discussion

Conclusion