The article has been devoted to issues connected with the alloplasty and hip joint endoprostheses, that elements are being developed, which is supported by strength, tribological tests on used biomaterials, incl. polyethylene or computer modelling based on e.g. finite element method (FEM). In this paper, the results of research on the impact of the material articulations of the system head – acetabular and friction conditions on strength parameters of polyethylene components in the hip joint endoprosthesis. Numerical analysis of this friction node was carried out, using the ADINA System computer program and the simulations were performed at various friction conditions for metal/ polyethylene and ceramic/ polyethylene articulations with various UHMWPE modifications. The simulations results have shown the influence of tested material associations and friction conditions on parameters related to the strength of polyethylene cups, i.e. their displacements, stresses and deformations.

Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO₃^–2), phosphate (PO₄^–3) and hydroxyl (OH^–) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca₁₀(PO₄)₅(OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties.