【作者】 曾宪林；

【导师】 杨述华；

【作者基本信息】 华中科技大学 ， 外科学， 2010， 博士

【摘要】 [目的]1、制作出犬非骨水泥型人工股骨柄假体,建立犬人工关节置换的动物模型；2、探讨真空下在犬钛合金人工股骨柄上等离子喷涂纯钛后复合HA-Ti阶梯式涂层的结构特点,力学强度和固定人工关节假体的可行性,并寻找该复合阶梯式涂层的最佳工艺流程；3、观察骨-涂层-假体间界面的组织结构和功能变化。[方法]1、制作犬非骨水泥型人工股骨柄假体,进行犬人工假体置换,检测关节功能、X线片、骨-涂层界面的结合强度以及观察涂层界面的结构；2、制作采用不同等离子喷涂功率、距离制备的纯HA涂层并检测其剪切强度；基于真空和大气下制备假体的纯Ti基层,HA涂层和复合Ti-HA阶梯式梯度涂层,分别检测和比较各假体涂层的剪切强度、显微组织和结构；3、硬组织骨切片组织学检测和骨界面显微观察。[结果]1、人工股骨柄置换后位置和关节功能良好,无松动表现；HA+Ti+A组剪切强度为16.04±0.95MPa,HA+Ti+V组为20.08±1.95MPa,Ti+HAG+Ti+V组23.43±0.37MPa,显著统计学差异(P<0.05)；SEM示Ti+HAG+Ti+V组涂层-骨之间结合紧密,优于HA+Ti+V和HA+Ti+A组；Ti+HAG+Ti+V组骨结合率显著高于HA+Ti+V组和HA+Ti+A组(P<0.05)；2、选择喷涂功率为35kW、喷涂距离为80mm可以兼顾涂层的结构完整和结合强度的提高；真空下钛涂层的剪切强度为46.52±3.43MPa,大气下钛涂层的剪切强度为35.15±2.43MPa,两组比较有显著统计学差异(P<0.05)；Ti+HAG+Ti+V组涂层压剪强度平均为23.36±1.61MPa,高于HA+Ti+V组的18.52±1.63MPa,HA+Ti+A组的15.52±1.58MPa,具有显著性统计学差异(P<0.05)；涂层的显微组织与结构：(1)真空下钛涂层具有连续层状结构和低的气孔率,未见明显裂纹；Ti+HAG+Ti+V组涂层有连续层状结构,梯度涂层上的HA表面层中颗粒间结合致密,未见裂纹,气孔率低,从基体到涂层表面组织分布具有阶梯性；(2)钛涂层的XRD示真空下喷钛的晶体结晶完整,结构致密；Ti+HAG+Ti+V组的XRD显示HA与Ti基材的结合程度相对较高；(3)涂层的红外光谱示真空等离子喷涂的Ti基层适宜HA层的附着,Ti+HAG+Ti+V组涂层结晶度高；3、组织学观察：(1)股骨大结节下无骨质缺损现象,股骨柄固定牢固；(2)光镜下涂层与骨界面上的新生小梁骨已大部矿化与股骨通过板层骨连接；四环素标记荧光显示骨组织与涂层界面内均有新骨长入；Ti+HAG+Ti+V组每单位高倍视野下成骨细胞数和骨细胞数平均为28.9±3.5,高于HA+Ti+V组(19.4±2.4)和HA+Ti+A组(14.9±2.1),差异有显著性统计学意义(P<0.05)。(3)髓腔界面SEM显示：Ti+HAG+Ti+V组界面之间结合良好,拔出后断裂的层面位于骨组织内,Ti+HA+A和HA+Ti+V组拔出后界面断裂位于涂层内。[结论]1、基于真空下等离子喷涂纯Ti基层及HA-Ti阶梯式梯度涂层能提高骨-假体的结合能力、增强假体的稳定性；2、真空下采用Ti基层喷涂,HA-Ti粉末按比例梯度以及35kw喷涂功率、80mm喷涂距离的等离子喷涂的涂层具有致密度较大、孔隙率适中、与HA的结合强度和HA结晶度高的特征；3、基于真空下等离子喷涂纯Ti基层及HA-Ti阶梯式梯度涂层通过较好的骨长入来提高人工股骨柄的固定效果。更多还原

【Abstract】 [Objective] 1. To make artificial femoral stem of the no-cement prostheses and animal models of artificial joint replacement; 2. To plasma spray pure Ti on the artificial femoral stem prostheses under vacuum, then graded coat HA-Ti compound in order to understand the structural properties of these compound coating materials, their mechanical strengths and feasibility of artificial joint prostheses and to find the best technological process of graded coating this compound material; 3. To implant artificial femoral stem prostheses in dogs to observe the biological structures and property changes of bone, coating and prostheses.[Method] 1 Making artificial femoral stem prostheses made in no-cement, replacing artificial femoral stem prostheses in dogs, Joint function tests, X ray films, bone-coating interface bond strength were tested and interface structure of the coatings were observed; 2 Pure HA coatings were plasma sprayed under different power and distances. Shear strengths and structural properties were tested; 3. primary pure Ti, HA coating and graded Ti-HA coating were made under vacuum and air, their shear strength, microstructure and structure were tested and compared, histologic studies of bone biopsy and observe the structure between bone and coatings under microscopy.[Results] 1. Position and function of artificial prostheses in 3 groups were all good after replacement. No loose prostheses were found; Shear strength in pull-out testing was 16.04±0.95MPa in HA+Ti+A group,20.08±1.95MPa in HA+Ti+V group, and 23.43±0.37MPa in Ti+HAG+Ti+V group. Statistic differences were significant(p<0.05); SEM illustrated that bones bonded tightly with interfaces in Ti+HAG+Ti+V group, which was better than those in HA+Ti+V group and HA+Ti+A group. Bone bond rate in Ti+HAG+Ti+V group was much higher than that in HA+Ti+V group and HA+Ti+A group. 35kW spraying power and 80mm spraying distance can make both the structures of coating intact and bond strength strong.; The shear strengths between Ti coatings and substrates were 46.52±3.43MPa in Vacuum group, while they were 35.15±2.43 Mpa in air group. There were significant differences in these two groups; Average shear strength was 23.36±1.61 Mpa in Ti+HAG+Ti+V group,18.52±1.63MPa in HA+Ti+V group, and 15.52±1.58MPa in HA+Ti+A group; Statistic differences were significant(p<0.05); Regarding the analysis results of microstruction and structure:(1) In Vacuum group, there were continuous layer structure and low porosity on coatings, no big cracks were found under scanning electron microscope; In Ti+HAG+Ti+V group, there were continuous layer structure on the coatings, there were dense bond within the particles in HA surface layers of graded coatings, no big cracks were found. There were low porosity on coatings, even layer, no deep cracks, purely ladder like tissue distributors from the substrate to coating surface. (2) XRD results of Ti-coating showed that spraying Ti under vacuum had more intact crystallizations and denser structure; pure Ti substrate bond with HA was better in Ti+HAG+Ti+V group; (3) Analysis of the FTIR results showed that plasma spraying primary Ti was adapt to HA coating attachment. Crystallizations in Ti+HAG+Ti+V group were better; 3 In the respect of histological results:(1) there were no bone defects under the Large tuberosities, The femoral stems were fixed firmly.(2) under microscopy, the majorities of new bones on the coating-bone interfaces had been mineralized, and connected with femurs through Lamellar bones; From the Tetracycline marked bone tissues, we found that new bones had grown into coatings. There were averagely 28.9±3.5 osteoblasts and oesteocytes per view under microscopy in Ti+HAG+Ti+V group, which was more than those in HA+Ti+V group (19.4±2.4), and HA+Ti+A group (14.9±2.1).The statistical difference was significant.(p<0.05). (3) The SEM results of interface in the femoral medullary cavity illustrated good bond between interfaces in Ti+HAG+Ti+V group, broken layers were in the bone tissues after pulling out the prostheses, while broken interfaces were within the coatings in Ti+HA+A group and HA+Ti+V group.[Conclusion] 1. The technology of plasma spraying pure-Ti on the substrate of artificial femoral stems under vacuum and graded coating HA-Ti can improve bonding strengths between medullary and coatings, enhance stability of prostheses.2. Plasma spraying primary Ti under vacuum and graded coating HA-Ti,35kw spray power and 80mm spray distance in this trial can make density of the substrate high, the porosity appropriate, their bond strength and crystallizations with HA is high 3. The technology in this study can improve fixation ability of joints through better bone growing in.更多还原