CFPEEK Composite Materials For Hip Prosthesis Fabrication Wear And Biological Fixation

Objective The prosthesis loosening is a big problem. It is believed that two major issues contribute to the progress. The Stress shielding caused by the high elastic modulus of the metal may lead to osteolysis and bone loss; The debris produced by the wear around the prosthesis can activate macrophage and lead to a series of biological activities which cause the loss of the bone. Therefore, new materials have lower elastic modulus and better wear characteristics should be developed to replace metallic materials. The composite materials offer the prospect of a substantial reduction in stiffness may reduce or eliminate the stress shielding. But the issues addressed that is wear because the wear of composites is serious. In order to solve this problem, two new kinds of composite materials for prosthesis have been developed in this study. Their mechanical and biological compatibility is ideal. Some experimental studies have been done to demonstrate their wearing and biological characteristics.Materials and methods 1 -, Domestic PEEK and advanced molding methods were used to develop two kinds of composites: chopped carbon fiber reinforced PEEK composite(30% carbon fiber) and continuous carbon fiber reinforced PEEK composite(30% carbon fiber). Their elastic modulus are 44.35 Gpa and 69.1 Gpa respectively. Their wear characteristics were observed in dry and wet conditions in according with the national standards. The M-200 system was used in this experiment. The results were compared with UHMWPEN Ti-alloy and CoCrMo-alloy. The angles which the fiber wear against the interface is difference in(K 45 > 90 degree respectively. 2 ^ A comparative study of the bonding strength between the bone and CFPEEK composite column samples was completed using the pushing out methods.Results 1.The chopped carbon fiber reinforced PEEK and continuous carbon fiber reinforced PEEK composite have lower wear weight loss(0.0037g) > specific wear rate(2.403 X 10"3 cm3 )and friction coefficient(0.08)than Ti-alloy (wear weight loss 0.5385g ,specific wear rate 118.6X10"3 cm3 , friction coefficient 0.17), CoCrMo-alloy( wear weight loss 0.3713g ,specific wear rate 47.6010'3 cm3 , friction coefficient 0.08) and UHMWPE(wear weight loss 0.0047g ,specific wear rate 5.0 X 10"3 cm3 , friction coefficient 0.11). The wear rates of Ti-alloy, CoCrMo-alloy and UHMWPE are 49.4, 19.8 and 2.08 times higher than CFPEEK. There are no significant differences between wear angles. There are no significant differences between the chopped carbon fiber reinforced PEEK and continuous carbon fiber reinforced PEEK. 2^ The bonding strength of CFPEEK with surrounding bone have no significant differences with the developed implant materials .Conclusion The chopped carbon fiber reinforced PEEK and continuous carbon fiber reinforced PEEK composite have prospects of being used in the TFIA to replace metal materials for stem components. Comparing with the metal, it have a lower elastic modulus and a better wear resistance. We also think that some new kinds of CFPEEK composites might be used as the socket components. .Composite is a promising prosthetic material because of its perfect mechanical and biological compatibility.Postgraduate: Jia Qing Wei Directed by: Sun Jun Ying...