| The international trade in goods is highly dependent on the development of the shiping industry. Therefore, shiping industry is regarded as a traditional pillar industry in internaitional trade. The working condition and occupational competency of the seafarers who are deeply involved in this industry, had been received significant attention from the international labour organization. Findings from the previous research indicated that osteoarthritis is easily occurred in the seafarers, since they always carry out monotonous and repeated work in the narrow work space. Therefore, the development of the artificial joints is useful for the treatment of the occupational diseases of seafarer and the improvement of their life quality, and a better labor relation. Furthermore, the research on the artificial joint and associated studies can provide a positive impact to the development of the shipping industry.Once a prosthesis is introduced into the body, the wear particles are inevitably produced during the prosthesis’life-time service. Wear particles from replacement joints had been received significant attention due to the following primary reasons. Firstly, the wear particles are important information carriers about microscopic wear mechanisms of artificial hip joint components, and secondly joint prostheses undergo osteolysis which is initiated by the biological response to wear particles. In this study, wear simulator was used to generate Ultra High Molecular Weight Polyethylene (UHMWPE) wear particles. Two-dimentionl morphology, three-dimentional geometry, surface topography and mechanical properties of UHMWPE wear particles were investigated at a nanometre-scale. Findings in this study are beneficial in understanding the wear mechanisms taking place in joints and can be used in early detection of osteoarthritis. Furthermore, the information may be useful to extend the service life of the implants by developing new biomaterial and strategies for controlling and minimizing the production of biologically-active wear particles.Atomic force microscopy (AFM) was used to quantify wear particle topographic features and nano-mechanical properties. It was found that nano-and submicron-sized particles had a granular shape, a much greater modulus and smoother surface than that of the micron-sized particles and bulk polymer sample. These differences revealed that the micron particles were most likely to be produced under macroscopic polymer asperity wear, while the nano-and submicron-sized particles were generated under microscopic polymer asperity wear. Furthermore, the results of this study have clearly shown that granule and platelet particles had a stronger wear resistance and better lubricant retention than that of fibrous and flake-like particles.Experiment carried on hip joint wear simulation not only can be used for material screening and ranking purposes, but also generation of wear particles. Lubricant and initial suface texture of joint components are critical determinants in wear behavior and particle morphology. Therefore, the influence of lubricant and surface texture of hip joint components on wear behavior and the morphology of UHMWPE wear particles was investigated in this sudy. White light interferometer and SEM were used to charactersie the surface topography of wear components and the morphology of wear particles. Findings in this study can provide a better understanding of wear mechanism of hip joint and an optimal method for particle generation.Size and morphology of wear particles from pin-on-plate wear rig, hip simulator and in vivo were compared in this study. Pin-on-plate wear rig produced much more nano particles and less micron particles than that of hip simulator and in vivo. The motion path and load can be the main determinants. However, the mean length of nano particles from in vivo was much larger than that of pin-on-plate wear rig and hip simulator. The reasons for this difference should be particle migration and poor working condition in vivo environment. |
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