Investigation of Novel, Internally Hollowed Structured Stainless Steel to Reduce Stress Shielding

Abstract

There are many aspects that have direct effects on total hip replacement performance (THR), such as material properties, applied loads, surgical approach, femur size and quality, prosthesis design, bone-implant interface etc. One of the purposes to study different structures in THR is reducing the stress shielding. For the current study, an innovative hollow spherical structure is developed for femoral hip stems. The aim is to extract volume in the spherical shape from the stainless-steel hip implant stems, in order to focus solely on correlating with titanium behavior. Internal geometry for the femoral stem is optimized in order to transfer more stress onto the bone. Moreover, the approach involves extracting volume in the spherical shape from the internal structure to reduce stress shielding. A new novel implant is proposed that demonstrated a reduction in stress shielding. The sphered models have a smaller young’s modulus and strength than the solid stainless-steel sample. The spheres in hollowed structures reduce the stress shielding and they transfer more stress onto the bone when compared to the solid stainless-steel models. This approach also involves restructuring a hard material, such as stainless steel, to enhance osseointegration. The reduction of the young’s modulus and stress directly depends on the volume of the hollow spheres in the models; however, there is a certain volume that can be extracted from solid