Strength analysis & comparison of SS316L, Ti-6Al-4V & Ti-35Nb-7Zr-5Ta used as orthopaedic implant materials by FEA

Femur is leg bone of the human body undergoing more deformation. Being longest and heaviest in size, failure of femur neck is the most common among bone failures in human especially in woman. Orthopedic implantation is done in case of failure. Before implantation it is necessary to analyze the perfectness in case of its material property, size and shape, surface treatment, load resistance and chances of failure. Analysis is done for the stresses formed in femur implant of SS316L, Ti-6Al-4V & Ti-35Nb-7Zr-5Ta materials under static loading condition using NASTRON software. Since each femur carries full body weight, analysis is done for 25kg, 50kg, 100kg, 200kg loads, including the cases of patient carrying certain weight. From analysis it is found that the loads have no effect on failure of implant, since the values of stresses and deformation are very low. Thus failure of implant is maximum by wearing, corrosion and all due to improper material selection of implant. And based on the analysis it can be concluded that, the displacement of the femur cup Ti-35Nb-7Zr-5Ta inside the bone socket is acceptable and well within the limits for implantation, it makes the patient feel free to move his leg. Analysis is done for the stresses formed in femur implant of Ti-6Al-4V & SS316L materials under static loading using FEA techniques. Since each femur carries half of the body weight, we have taken the extreme weights, that is, the least possible weight and the heaviest possible weight. From analysis it is found that the loads have no effect on failure of implant since the values of stresses and deformation are very negligible. Since Ti-6Al-4V & Ti-35Nb-7Zr-5Ta are low density materials compared to SS316L, which have excellent bio compatible and mechanical properties, it is ideal for the use of an implant in surgeries. Based on the analysis SS316L is a high density material (7970kg/m3) for implantation, it makes the patient feel heavy to move his leg. It will further lead to infection and disorders like wearing, loosening of implant, bone swelling, thus effecting bone tissue. Finally the success of implantation depends on implant material and size, implantation method and its handling by the patient.