Papers by Keyword: Endoprosthesis

Abstract: This paper deals with applications of biomaterial in the human body. Each biomaterial is characterized by biofunctionality and biocompatibility [1]. The choice of biomaterial for medical applications is established on mechanical properties. Therefor the Ti6Al4V alloys, which properties are relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance [2], are most widely used in biomedical replacements, implants, and prosthesis. Despite the excellent properties of the titanium alloy, endoprosthesis often fails and the hip replacement is necessary. Common causes are overloading and cracking, static or dynamic. Other causes of failure include injury, implantation failure, manufacturing inaccuracies, and non-compliance with the manufacturing process.

Abstract: It can be stated that over the last ten years in the European Union, the number of bone fractures caused by osteoarthritis has increased twofold. More than 100,000 hip or knee joints in total were implanted in Germany during one year. Within ten years, 5% of them have failed by aseptic loosening.The non-invasive determination of friction forces and control of their values during lubrication of cartilage cells on the superficial layer of human joint surfaces before implantation has a significant but not sufficient impact on the observation of the early abrasive wear of the cartilage joint and development of osteoporosis. From this fact was drawn the inspiration for the performed investigations related to the endoprosthesis surface parameters because knowledge of the roughness of prosthesis surfaces and friction forces and their control methods permits provision of a necessary standard deviation of the gap height and finally information about the implantation possibility. This paper has been prepared based on the objective of European Project UE Grant IRSES,612593, 2013-2016 to represent the methodology and goal of the idea described in and make a wider discussion possible on this subject for further developments during the realization.

Abstract: The paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of selected kinematic pairs were conducted with the PT-3 tribometer in Ringer’s solution a constant load 2.0 kN, rotational speed of the rotating specimens (Ti13Nb13Zr and Ti6Al4V) 30 rev/min, and test duration 1 or 2 hrs.

Abstract: The paper present the analysis of metal prosthesis head stress state of hip joint endoprosthesis which is a result of variable loads during human motor activity and its influence on the erosion of materials. The analysis of stress state was made with use of FEM – ADINA numerical tool. The analysis of surface erosion process was made with use of the scanning electron microscope. To the researches was taken for heads from CoCrMo bearing shell and polyethylene UHMWPE.

Abstract: The scale of influence of the single crystal sapphire crystallographic plane orientation and grinding conditions on the material removal rate, surface finish and the state of sub-surface layer have been studied under Low-Temperature Precision Grinding (LPG). The schemes of forming partial spherical heads for human hip joints endoprostheses are considered and elaborated. The possible versions of forming the spherical heads of endoprosthesis based on the novelties in kinematics and the mode of material removal are discussed.