Wear and wear-induced debris is a significant factor in causing failure in implants. Reducing contact pressure by using a textured surface between the femoral head and acetabular cup is crucial to improving the implant’s life. This study presented the effect of surface texturing as dimples on the wear evolution of total hip arthroplasty. It was implemented by developing finite element analysis from the prediction model without dimples and with bottom profile dimples of flat, drill, and ball types. Simulations were carried out by performing 3D physiological loading of the hip joint under normal walking conditions. A geometry update was initiated based on the patient’s daily routine activities. Our results showed that the addition of dimples reduced contact pressure and wear. The bottom profile dimples of the ball type had the best ability to reduce wear relative to the other types, reducing cumulative linear wear by 24.3% and cumulative volumetric wear by 31% compared to no dimples. The findings demonstrated that surface texturing with appropriate dimple bottom geometry on a bearing surface is able to extend the lifetime of hip implants.

A new generation of bone scaffolds incorporates features like biodegradability and biocompatibility. A combination of these attributes will result in having a temporary bone scaffold for tissue regeneration that mimics the natural cancellous bone. Under normal conditions, scaffolds will be gradually eroded. This surface erosion occurs due to the immersion and the movement of bone marrow. Surface erosion on bone scaffolds leads to changes of the morphology. The mechanical response of the scaffolds due to the surface erosion is not fully understood. The aim of this study is to assess the influence of the dynamic immersion condition on the degradation behaviour and mechanical properties of porous magnesium. In the present work, load-bearing biomaterial scaffolds made of pure magnesium are immersed in simulated body fluids (SBF) with a certain flow rate. Samples with different porosities are subjected to tomography and are used to develop virtual 3D models. By means of numerical simulations, the mechanical properties, for instance, elastic modulus, plateau stress, 0.2% offset yield stress and energy absorption of these degraded samples are collected. The findings are then validated with the values obtained from the experimental tests. Finite element method enables the study on the failure mechanism within the biomaterial scaffolds. The knowledge of how weak walls or thin struts collapsed under compressive loading is essential for future biomaterial scaffolds development. Results from the experimental tests are found in sound good agreement with the numerical simulations.

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