In this study, we investigated the mechanical behavior of a knee replacement prosthesis (TKR) manufactured by the Zimmer company. To facilitate our analysis, we initially utilized a coordinate measuring device, specifically a contact 3D scanner, to prepare a cloud-of-point model of the prosthesis. This scanning process allowed us to accurately capture the geometry and dimensions of the TKR, providing a detailed representation of its physical structure. By utilizing this advanced scanning technology, we ensured that our subsequent simulations and analyses were based on precise and reliable data, enabling a thorough examination of the mechanical performance of the knee replacement prosthesis. ABAQUS software was then used to analyze the threedimensional model and nonlinear static analysis was performed on the model. This simulation examined the mechanical performance of the prosthesis for different weight ranges, and the distribution of stress, strain, and displacement within the prosthesis was analyzed. The results show that the maximum stress created in the investigated prosthesis increases from 16MPa to 64MPa per weight of 55 kg to 75 kg. Although, with a 26% increase in the weight of the individual using a knee prosthesis, the maximum stress created in the prosthesis increases by 76%. This type of prosthesis is suitable for the maximum weight category of 80 kg, as it has a reliability coefficient of 3. In light of these results, it is clear that weight categories must be taken into account when considering a particular prosthesis. Otherwise, the prosthesis may be destroyed due to the application of larger forces during various everyday situations and result in serious knee injuries.