| When doctors discovered the toxicity of bone cement and metal wear particles,cementless hip prostheses were developed,which is mainly made of metal acetabular cup and femur hilt covered with bioactive coating.As a joint surface this cementless hip prostheses will match up the ball head and liner with low friction coefficient.However,when the prosthesis is implanted in the body,there are the unavoidable flaws,such as the wearing on the joint surface,fretting and corroding at the interface of different materials.As time goes on,the prosthesis wear accompanied by particles release and the coating peeling accompanied by the metal material exposed to induce osteolysis around the prosthesis.Eventually,the prosthesis loosens and the prosthesis fails.In order to effectively avoid the occurrence of the above situation,taking a kind of new material with good biological safety and high strength as new artificial hip joint prosthesis will be the key to technological progress of modern hip prostheses.In this study,firstly,it was retrospectively analysed and summarized to the prostheses of hip joint made from Jiangxi microcrystalline ceramics(J.M.C)in the1970s and 1980s,including the material characteristics and design of the prosthesis,and biological characteristics and osteointegration effect of prosthesis.Secondly,based on the review and analysis of the modern microcrystalline ceramics,new lithium silicate microcrystalline ceramic materials(Li2O-Al2O3-Si O2,LAS)and Zirconia toughened Alumina(ZTA)were optimized for manufacturing.Finally,using the digital model and stress analysis of the prosthesis,the geometry design and material application of the new all-ceramic hip joint prosthesis were proposed.Based on the microcrystalline ceramic materials and placed emphasis on biological performance of them,the research provides a new frame for the material types,manufacturing methods and conformation design of the new domestic all-ceramic hip joint prosthesis.The first chapter describes the current situation and significance of total hip prosthesis and the development of total hip prosthesis in the last 100 years is reviewed,and the advances in artificial hip materials are highlighted.According to the functional characteristics of medical bioactive ceramics and bioinert ceramics and their correlation with total hip arthroplasty,the importance and development prospect of advanced manufacturing and clinical application of biological microcrystalline ceramics were put forward.The second chapter introduces the general follow-up of the patients with J.M.C-I,II hip prosthesis.In 1980-1981,a total of 23 patients(24 hips)were recently followed up(within 0.2?1.5 years after surgery).Long-term follow-up(31 to 37 years after surgery)between 2013 and 2016 included 8 patients(9 hips).X-ray of the patient's hip,Harris score,VAS score and other data showed that this kind of prosthesis has good biosecurity and strong osseointegration effect.The prostheses can be in vivo for a long time and well be tolerated by patients.However,due to poor pseudomechanical properties,some prosthesis structures were damaged and complications occurredThe third chapter describes the J.M.C raw material and the manufacture of its products.On the one hand,a number of parameters of the J.M.C joint materials removed from the bodies were analyzed,including surface morphology,crystal structure,principal composition,bending strength,elastic modulus,toughness,hardness,coefficient of thermal expansion,etc.The results showed that the composition of the J.M.C was simple and the purity of the product was obviously insufficient.On the other hand,this material has been analyzed in biological experiments,including osteoblastic metabolism and adhesion,mineralization of the skeleton,animal sensitization,osteointegration effect,which has good biological characteristics to be confirmed.In the fourth chapter,based on the research results of modern microcrystalline ceramics and J.M.C the purity of ceramic raw materials is improved and the ratios of ceramic components were changed,which includs the increase of Si O2ratio,the addition of Ti O2,P2O5,Zr O2components,and a new type of LAS microcrystalline ceramic subassembly was fabricated.The physical properties of LAS were characterized,including surface morphology,crystal structure,principal composition,bending strength,elastic modulus,toughness,hardness,coefficient of thermal expansion,etc;the biochemical properties of LAS were characterized,including metabolism,adhesion,morphology,mineralization and gene expression of osteoblasts,and animal sensitization,visceral toxicity,and osteointegration effects of LAS.The results show that the mechanical properties of the new LAS are significantly improved and the biological properties are better than that of J.M.C.Some key parameters in the manufacture of ZTA ceramics are also set in this paper.Finally,a high strength artificial total hip joint material was constructed to meet the requirements of all-ceramic design.Finally,the high strength ZTA microcrystalline ceramics that meet the requirements of all-ceramic design were obtained,and the construction of artificial total hip joint material was completed.In the fifth part,the digital model of the new type of hip joint prosthesis and pelvis was established and the two-part assembly were matched,with which the properties of loading materials and the analysis of the pressure on materials were carried out.The advantages of mathematical model design in prosthesis design were expressed,with which the shape design and manufacture of the new artificial hip joint can be provided. |
PDF Full Text Request