Failure Analysis of Cementless Hip Joint Prosthesis

Abstract

In this changing global scenario, modification, transplantation, and replacement can be the eternal solution for most of the problems in the medical field. Hence replacement technique finds a very prominent place in medicine as a remedy having closely tied up with biomechanics. One of the most important joints in the human body is the hip joint, the big and complex joint. Many researches were conducted and many are in progress, but most of these works use simplified models with either 2D or 3D approaches. The hip joint is formed by four components like femoral head cortical bone, stem, and neck. In this system we can find orthotropic and isotropic materials working together. The main objective of this research is to develop a three dimensional surface and solid finite element model of the hip joint to predict stresses in its individual components. This model is a geometric non-linear model, which helps us understand its structural mechanical behavior, seeming to suggest with advanced research in the future new hip joint prosthesis, as well as to prove the prosthesis joint interaction before being implanted in the patient. This research explains a complete human hip joint model without cartilaginous tissue, using ANSYS 10.0 Multiphysics Analysis for nine different postures in hip joint using three different materials (CoCr, Ti6Al4V, and UHMWPE) to calculate fatigue life. The result obtained from the analysis of surface model and solid model serve to help in predicting the life cycle, surface characteristics, shear stress in XY plane, stress concentration and areas that are prone to failure. Von Mises stress on the surface of our model facilitates us to equip and design an optimized prosthesis device having unique materials composition , with a highly bio-compatible and durable alloy at a low cost could be produced. In this way, a first important step towards the structural characterization of human hip joint has been developed.

Biomechanical Effects of the Porous Structure of Gyroid and Voronoi Hip Implants: A Finite Element Analysis Using an Experimentally Validated Model

“…As shown in Figure 7, the maximum stress is located at the neck region area of the hip implant for all three designs. The observation was similar to another study, in which the maximum VMS occurred below the neck for the medial part, and as for the lateral side, it happened around one-third of the distance from the neck region [35,51]. Not only that, but the von Mises stress was also distributed throughout the implant until the distal part.…”

Elastic Behavior of Uncemented Hip Prosthesis Made of Composite with Material Property Grading

“…Furthermore, new design helps in reduction of maximum interface shear stress by about 50% on the lateral and medial aspects of the femur as compared with titanium stem. Also reduction of 17% and 11% is found on the lateral and medial facets of the femur, respectively, when comparing with model II of FGM [1,2].…”