Numerical Evaluation of Reduction of Stress Shielding in Laser Coated Hip Prostheses

The increasing use of titanium alloys as biomaterials can be attributed, among other factors, to their low Young modulus compared to other alloys with similar mechanical strength. However, Ti-6Al-4V alloy, the alloy most widely used in implants, has a stiffness of about 110 GPa, which is much higher than the typical stiffness of 20 GPa of human bone. In the specific case of hip arthroplasty, this difference in stiffness reduces the load imposed on the femur through the stress shielding phenomenon, which, in the medium term, usually results in the loss of bone density. One way to reduce this phenomenon is by using TiNbTaZr (TNTZ) alloys, which have a stiffness of about 47 GPa. This work uses numerical simulation to evaluate the effectiveness of TNTZ laser coated on a Ti-6Al-4V hip prosthesis in reducing stress shielding. The results show that this may improve the performance of the prosthesis, extending its service life.