PROSPECTS OF USAGE OF MATERIALS WITH FULLERENE COATINGS FOR ENDOPROSTHESIS OF JOINTS

摘要

Research of physical-chemical properties of fullerene based materials which was actively conducted last year has opened a lot of new possibilities for practical applications of these materials. Among the most promising applications of these materials is its usage as coatings in fricton pairs to increase wear resistance that is the topical task for some medical devices. Modern design of hip prosthesis is usually based on usage of titanium alloy Ti 6A1 4V and polyethylene with superhigh molecular weight Chirulen. Friction pair of such endoprosthesis consists of titanium head and polyethylene cup. One of the shortcomings of the endoprosthesis is insufficient tribological properties of the device. For example, polyethylene wearing of such friction pair makes from 75 up to 250 μm per year. This process is accompanied by derivation of wearing products, which are collected in ambient tissues and cause inflammatory, allerginic and other negative processes in an organism, and also displacement wearing surfaces relative to one another. It results in derivation of undesirable gap between the surfaces, and further - to loosening of the endoprosthesis and loss of its functional properties. Therefore, due to loosening, 3-5 years after operation almost all existing types of hip prosthesis should be substituted completely or need replacements of some components. Wearing rate of components in ceramics - polyethylene friction pair is about an order of magnitude lower. But due to low ceramics toughness usage of ceramic heads in hip prosthesis is limited. To improve tribological properties the ceramic - polyethylene friction pairs are used where the wearing of components is about tenfold lower. However due to low toughness usage of ceramic heads is limited. Therefore search of new designs and materials for manufacturing of friction pairs gains the increasing urgency. This study is dealing with fullerene based materials as coatings to wearing surfaces of hip endoprosthesis. The physico-chemical properties of fullerene C_(60 on) coating on Ti 6Al 4V titanium alloy were studied and wear resistance of polyethylene Chirulen coupled with this alloy coated or uncoated by fullerene was measured. For comparison the wear was measured for pair Al_20_3 medical ceramics - Chirulen.