Jiajia Cen,Qin Chen,Kai Chen,Xinyue Zhang,Haiyan Feng,Cunao Feng,Xiaowei Li,Dekun Zhang,Shirong Ge
Environmental factors greatly affect the tribological behavior of hip joint materials in synovial fluid. In this paper, four groups of the synovial fluid with different concentrations of albumin (Alb), γ-globulin (γ-Glo), hyaluronic acid (HA), and phospholipids (PLs) were prepared based on the concentration of each component of the synovial fluid after artificial joint replacement. Then, taking cobalt-chrome-molybdenum (CoCrMo) and high crosslinked polyethylene (XLPE) as research objects of the hip joint materials, the tribological behaviors in the synovial fluid with different pH values and temperature were systematically explored, elucidating the influence mechanisms of external conditions and synovial fluid components on friction and wear behaviors. Results indicated that the tribological behaviors of hip joint materials were significantly affected by the pH value and temperature of the synovial fluid. The coefficient of friction (COF) of the hip joint materials in the synovial fluid initially decreased and then increased with the pH value, reaching a minimum at pH= 8.0, and sample 4 was the most sensitive to pH change. The COF of the hip joint materials in the synovial fluid ascended with temperature, showing an opposite trend to calf serum (protein concentration of 30 mg/mL) in the standard experiment. In addition, the wear of the hip joint materials was more severe in the synovial fluid with lower pH (pH=7.5 and pH=8.0) and mild in the synovial fluid with higher pH (pH=8.5). Additionally, the wear of the hip joint materials in the synovial fluid and calf serum in the standard experiment increased with the ascend of temperature, and the wear in calf serum in the standard experiment was the most affected by temperature. In conclusion, this study sheds light on the tribological behaviors and mechanisms of artificial hip joints under simulated working conditions, providing a crucial foundation for accurately evaluating the bio-tribological characteristics of artificial joint materials.
Ultrahigh-molecular-weight-polyethylene (UHMWPE) is extensively applied to make bone and cartilage implants in the field of biomaterial application. UHMWPE matched with a metal or ceramic component withstands the long-term effect of cyclic stress, which induces UHMWPE serious wear, and affects the service life of the artificial joint. This investigation focuses on the influence of pores on the mechanical and tribological property of UHMWPE. The porosity, crystallinity, yield strength, tensile strength, hardness, compression yield strength, creep resistance, wettability, friction performance, and wear mechanism of solid and porous UHMWPE were evaluated and compared. The research results indicated that the pore had a remarkable influence on the mechanical, friction, and wear property of UHMWPE. The porosity of porous UHMWPE was 29.7% when 50 wt. % sodium chloride (NaCl) was added and the pore size was about 200 μm. The crystallinity, hardness, creep resistance, strength, and elongation decreased after NaCl was added and dissolved. However, the yield strength in the tensile and compression test was closer to that of the natural cartilage. The friction coefficient and wear loss of porous UHMWPE were higher than that of solid UHMWPE in dry conditions, but these values of porous UHMWPE were lower than that of solid UHMWPE in the calf serum lubrication condition. The main wear mechanism of porous and solid UHMWPE was abrasive. The lubricity of calf serum reduced wear surface scratches and furrows, especially for porous UHMWPE.
危险品化学品经营许可证（带存储）