**1. Introduction**

Metal-on-metal total hip arthroplasty has been increasingly selected in hip replacement surgery for diseased hips, especially for younger patients with higher activity levels [1]. This is due to the high number of failure cases that have been found in the use of metal-on-polyethylene and ceramic-on-polyethylene bearings, where polyethylene wear induces osteolysis and aseptic loosening. Meanwhile, the use of ceramic-on-ceramic is prone to failure due to cracking due to high-intensity activities, generally carried out by younger users.

Looking at the data published by the Australian Orthopedic Association (AOA) in 2020 [2] shows that the total failure cases of hip arthroplasty with metal-on-metal bearings are relatively higher than other options. Even so, metal-on-metal is still widely used in several developing countries, including Indonesia to meet the domestic market's need for hip joint implants independently without having to import [3–5]. This is based on the advantages of metal-on-metal in terms of relatively affordable prices, easily available raw materials, and limited production equipment.

**Citation:** Ammarullah, M.I.; Afif, I.Y.; Maula, M.I.; Winarni, T.I.; Tauviqirrahman, M.; Akbar, I.; Basri, H.; van der Heide, E.; Jamari, J. Tresca Stress Simulation of Metal-on-Metal Total Hip Arthroplasty during Normal Walking Activity. *Materials* **2021**, *14*, 7554. https://doi.org/ 10.3390/ma14247554

Academic Editors: Giovanni Vozzi and Oskar Sachenkov

Received: 29 October 2021 Accepted: 6 December 2021 Published: 9 December 2021

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The main problem with using metal-on-metal is the production of metal ions due to metal wear particles that can spread throughout the body from the bloodstream. These metal ions cause poisoning and various negative reactions in the human body system. Efforts that can be made to prevent implants from failing are the further evaluation of the choice of metal material used for metal-on-metal total hip arthroplasty. Several metal materials are commonly used for metal-on-metal bearings, including cobalt chromium molybdenum (CoCrMo), 316 L stainless steel (SS 316L), and titanium alloy (Ti6Al4V) [6].

In evaluating the performance of total hip arthroplasty, several previous studies used the von Mises stress, such as that conducted by Chethan et al. [7] and Carreiras et al. [8]. However, the use of Tresca stress is considered to be better than the von Mises stress because the Tresca failure theory has a smaller safety area than the von Mises failure theory, so it can be said that the use of Tresca is safer than of von Mises [9]. Research related to the evaluation of the performance of artificial joints with Tresca stress has previously been carried out by Usman and Huang [9] and Abdullah et al. [10]. Unfortunately, the evaluation of the use of materials for metal-on-metal total hip arthroplasty with Tresca stresses has not yet been carried out.

To accommodate this problem, the current study focuses on evaluating the Tresca stress in metal-on-metal bearings with different materials. A finite element-based prediction model has been created to solve problems using computational simulations. Gait loading has been used to reflect Tresca stress conditions more accurately in daily activities for simulating metal-on-metal total hip arthroplasty.
