Design of a hybrid artificial hip joint using finite element analysis

Abstract

Rehabilitation is an important branch of biomedical engineering specializations that is exceedingly related to the healthcare delivery and its improvement, one of the most important topics of rehabilitation is prosthesis that is related to resolving the problems of the amputations and artificial joints. The later has been widespread recently due to the bone diseases and traumas. Subsidence, stress shielding, fatigue fracture, stiffness mismatching and expensive prices are the most common problems with metallic artificial hip joint, which led to presence of different artificial joints modalities with different qualities. This research aims to enhance the healthcare by providing an artificial hip joint that proposes a reasonable solution for these problems, and that through design a hybrid joint composed of hybrid stem that consist of core and coat with two different materials CoCrMo and PEEK for each of them respectively. The CoCrMo core exhibits elevated mechanical properties and optimal corrosion resistance under friction condition and has an elliptical geometry that permit handling the maximum load that is applied on the joint. On the other hand the S-shape PEEK coat provides high flexibility and osteointegration that makes it able to handle the rest of the load that is applied on the joint. For the suggested design, special mechanical analysis tests using finite element analysis methods were carried out then repeated 10 times with gradient of 12.8º in the range of motion angle to check the efficiency of the proposed design, it was observable that the highest value of the maximum stress presented in the model analysis was 345.34 MPa, this means the suggested materials and dimensions provides efficient of 64%. Finally, the proposed design was printed as 3D prototype to verify the reasonability of the model dimensions.