The Role of the Assembly Force in the Tribocorrosion Behaviour of Hip Implant Head-Neck Junctions: An Adaptive Finite Element Approach

Abstract

The cyclic loading, in the corrosive medium of the human body, results in tribocorrosion at the interface of the head-neck taper junction of hip implants. The resulting metal ions and wear debris adversely affect the local tissues. The force applied by surgeons to assemble the junction has proven to play a major role in the mechanics of the taper junction which, in turn, can influence the tribocorrosion damage. Recently, finite element method has been used to predict the material loss at the head-neck interface. However, in most finite element studies, the contribution of electrochemical corrosion has been ignored. Therefore, a detailed study to investigate the influence of the assembly force on the tribocorrosive behaviour of the head-neck junction, which considers both the mechanical and chemical material removal, is of paramount interest. In this study, a finite-element-based algorithm was used to investigate the effect of assembly force on the tribocorrosion damage at the junction interface, for over four million cycles of simulated level gait. The patterns of the material removal in the modelling results were compared with the damage patterns observed in a group of retrieved modular hip implants. The results of this study showed that for different cases, chemical wear was in the range of 25–50% of the total material loss, after four million cycles. A minimum assembly force (4 kN for the studied cases) was needed to maintain the interlock in the junction. The computational model was able to predict the damage pattern at the retrieved head-neck interface.

Design and Performance Evaluation of a Novel Spiral Head-Stem Trunnion for Hip Implants Using Finite Element Analysis

“…A quadratic mesh element employs a non-linear shape function in which nodes are interpolated using a polynomial of a higher order [ 60 ]. Recent research into hip implant-based finite element studies have used quadratic tetrahedral [ 7 , 61 , 62 , 63 ] mesh elements more than any other form. According to Ansys [ 64 ], the preferred choice for complicated nonlinear geometry is tetrahedral mesh elements.…”

“…Wear studies are important in determining joint performance. Earlier works [ 46 , 61 , 66 , 67 , 68 ] have utilized the Archard wear model to estimate the wear rate according to Equation (1): …”

Advancements in Modelling the Tribocorrosion Current

“…Some of the constants are captured by conducting a few experiments and fitting the models on results. [3,33,41,43,44] These constants do not include the dynamic time-dependent nature of the contact such as its roughness, hardness, and the size of wear particles. This may necessitate the use of computational simulations such as those in [45][46][47][48][49] to better understand how and why the contact situation varies over the time of rubbing with/without the entrapped third-body particles and captivated fluid film.…”

“…Some other constants are not directly measured, and they are obtained in an ad‐hoc fashion. Some of the constants are captured by conducting a few experiments and fitting the models on results [3,33,41,43,44] . These constants do not include the dynamic time‐dependent nature of the contact such as its roughness, hardness, and the size of wear particles.…”

The influence of surgical technique guidance and surgeon’s experience on the femoral head assembly in total hip arthroplasty

“…In addition to the design of the total hip implant, there is increasing evidence that the assembly procedure of modular components plays a crucial role for taper stability and thus for fretting and corrosion of modular hip endoprostheses [ 15 – 17 ]. Reduced wear in the taper-head junction with increasing assembly forces was reported [ 18 , 19 ].…”