人工关节金属磨损颗粒体外制备分离方法的实验研究

[目的]设计一种体外制备、分离人工关节金属磨损颗粒的方法，并验证这种颗粒用于医学实验的可行性。[方法]用钛铝钒合金、钴铬钼合金材料分别制成球磨罐（国家发明专利，申请号：03142073．7），球磨罐内装有用同种材料制成的磨块；向该球磨罐内注入模拟生物体液；震动球磨得到颗粒混悬液。梯度离心获得金属颗粒。对颗粒进行：（1）元素成分鉴定；（2）颗粒大小鉴定和粒度分析；（3）扫描电镜对颗粒的表面形态观察；（4）将颗粒与J774A．1巨噬细胞共同培养，观察细胞吞噬颗粒的情况。[结果]通过此方法成功产生并分离出大量直径1μm左右的钛合金和钴铬钼合金颗粒。（1）元素分析证实整个处理过程中无杂质成分污染；（2）钛合金颗粒的平均直径Dv90：1．009，钴铬钼颗粒的平均直径Dv90：1．008，粒度分布曲线基本成正态；（3）扫描电镜图象显示颗粒大小均匀，形状多为不规则，与体内颗粒极为相似；（4）J774A．1巨噬细胞能完整吞噬2种材料的颗粒。[结论]此方法能持续大量产生人工关节假体金属材料的磨损颗粒，产生的颗粒能在各方面很好地模拟体内磨损颗粒，为今后人工关节假体松动相关研究的体内、体外研究提供可靠的颗粒来源。     

不同浓度金属磨损颗粒对破骨细胞体外分化的影响

[目的]观察不同浓度金属磨损颗粒对RAW 264.7在体外分化成破骨细胞的影响,明确浓度与破骨细胞分化数量的关系.[方法]真空球磨法制备人工关节磨损颗粒:RANKL诱导RAW 264.7体外分化成破骨细胞,通过TRAP染色,电镜扫描检测骨片吸收陷窝来鉴定破骨细胞;不同浓度人工关节磨损颗粒混悬液作用RAW 264.7,并用RANKL诱导后第7 d,TRAP染色后,光镜下计数破骨细胞数量.[结果]不同浓度磨损颗粒作用于RAW 264.7 7 d后,显微镜下计数破骨细胞数量,结果显示随着磨损颗粒混悬液浓度增加,RANKL诱导生成的破骨细胞增多,低、中、高浓度3组破骨细胞数均显著高于空白对照组(P<0.05),中、高浓度组破骨细胞数均显著高于低浓组(P<0.05),高浓度组破骨细胞数亦显著高于中浓组(P<0.05).[结论](1)RAW 264.7是一种较好的破骨前体细胞模型,RAW 264.7诱导形成破骨细胞的方法简便易行,所获得破骨细胞均一性好;(2)人工关节金属磨损颗粒为RAW264.7细胞向具有骨质吸收功能的破骨细胞转化发挥正向作用,而且与混悬液的浓度有量效关系.     

磨损颗粒、微动、压力与人工关节松动

本文就磨损颗粒，微动及压力等在人工关节无菌性松动发病中的作用作一简要综述。     

超低磨损聚乙烯人工关节材料的生物相容性评价

[目的]对超低磨损聚乙烯人工关节材料的生物相容性进行初步评价,为进一步的人体试验提供依据。[方法]根据国家GB/T-16886/ISO-10993对医疗器械外科置入物的评价要求,进行体外细胞毒性试验(CCK-8比色法)、溶血试验、急性/慢性全身毒性试验、肌肉置入试验。[结果](1)细胞毒性试验的试验组L929细胞在培养24、48、72 h后相对增殖率依次为95.25%、104.96%、102.81%,显示无细胞毒性;(2)血液相容性试验溶血率为0.81%,提示该材料无溶血作用;(3)急性全身毒性试验试验组小鼠无特殊行为学表现,试验组与对照组小鼠体重增加差异无统计学意义(P0.05);(4)肌肉置入试验术后病理切片证实该材料置入大鼠体内后炎性细胞反应逐渐减轻;(5)慢性全身毒性试验术后12周试验动物肝肾均无明显病理表现。[结论]该材料具有良好的生物相容性及安全性。     

人工关节磨损颗粒生物学特征研究进展

人工关节置换术是治疗许多晚期关节疾患的有效方法,然而术后发生人工关节无菌性松动使人工关节面临翻修的难题.人工关节无菌性松动的发病机制目前尚未完全清楚,但由磨损颗粒诱导的假体旁骨溶解被认为是最主要的因素.大量研究表明,磨损颗粒的特性与其引起的生物学反应密切相关.该文就磨损颗粒的分类,大小、形状及其在人工关节无菌性松动中的作用等方面作一简要综述.     

人工关节置换术后磨损颗粒与假体周围骨溶解的研究进展

人工关节置换术后磨损颗粒的产生是导致假体周围骨溶解的重要影响因素。目前研究认为磨损颗粒导致假体周围骨溶解的主要原因与植入假体的材料以及其产生的磨损颗粒通过各种作用对相关细胞如巨噬细胞、成骨细胞、破骨细胞等的刺激有关,诱导产生多种炎性细胞因子,激活和开放细胞信号和通路,产生长期慢性的炎症,导致假体周围骨溶解。为此,本文主要研究不同类型的磨损颗粒对假体周围骨溶解的影响,以及磨损颗粒在假体周围骨溶解进展过程中的机制,并且由此探讨如何减少磨损颗粒的产生以及阻断其在骨溶解进程的作用,以此来达到预防和治疗假体周围骨溶解的目的。     

磨损颗粒对滑膜细胞系胞间通讯的影响及其在人工关节无菌性松动 …

目的 通过观察磨损颗粒作用下滑膜细胞系胞间通讯的改变,探讨无菌性松动人工关节假体－骨界面纤维组织异常增生的生物学原因。方法 体外培养获得正常髋关节滑膜细胞系,借助荧光光淬灭恢复技术（ＦＲＡＰ）及激光扫描共聚焦显微镜监测加入１．５ｍｇ／ｍｌ（Ｗ／Ｖ）Ｔｉ合金,ＣｏＣｒ合金或ＵＨＭＷＰＥ颗粒悬液后滑膜细胞间通讯的改变。     

成骨细胞对人工关节金属磨损微粒的体外生物学反应

磨损微粒引起的假体周围骨溶解、无菌性松动是严重影响人工关节置换术中、远期临床疗效的重要因素〔1~4〕。大量研究证实,关节置换术后产生的磨损微粒数量惊人,每年在体内产生约5×1013亚微粒释放入关节腔〔1、5〕。金属微粒是重要磨损微粒之一〔3、6〕,与其他无法降解消化的微粒(如聚乙烯或骨水泥等)一样,当其持续刺激假体周围细胞(包括成骨细胞、巨噬细胞、成纤维细胞和破骨细胞等)时,正常吞噬反应将引起病理改变〔1、4〕。鉴于成骨细胞在假体周围骨代谢中具有重要地位〔3、7〕,阐明金属微粒对成骨细胞的影响极其重要。为此,本文将就近年…     

人工关节磨损微粒对体外培养外周血单核细胞的影响

目的：研究人工关节磨损微粒诱发骨溶解的机理，探讨不同微粒物质倡导骨溶解能力的差异。方法：通过体外培养人外周血单核细胞对超高分子聚乙烯微粒入钛合金（Ｔｉ６Ａ１４Ｖ）微粒反应，检测培养上清液中肿瘤坏死因子（ＴＮＦ－α）含量。结果：超高分子聚乙烯微粒和钛合金微粒均可刺激单核细胞，使之产生更多的ＴＮＦ－α，与对照组相比样差异有统计学意义（Ｐ〈０．０１）。但超高分子聚乙烯组与钛合金组的ＴＮＦ－α含量比较差异     

磨损颗粒诱导假体周围骨溶解生物学机制的研究

人工关节置换术是治疗各种晚期关节疾病的有效方法,术后发生人工关节无菌性松动是目前面临人工关节翻修主要原因.人工关节远期松动最常见的原因是假体磨损产生的颗粒诱发假体周围组织细胞产生一系列生物学反应,并导致假体周围骨溶解.大量研究表明,磨损颗粒刺激假体周围的巨噬细胞、成骨细胞、成纤维细胞等产生多种细胞因子,形成破骨细胞性骨吸收,同时影响成骨细胞的分化及功能,抑制骨形成.     

骨基质明胶颗粒/骨水泥复合材料固定人工关节假体的实验研究

[目的]探讨骨基质明胶颗粒(BMG)复合骨水泥(PMMA)用于人工关节假体固定的可行性.[方法]制备成年新西兰白兔股骨中上段15 mm骨缺损,于髓腔内置入直径3 mm的钛棒并以骨水泥或BMG/PMMA复合材料固定,模拟人工股骨头置换术之动物模型,分别进行术后步态、X线检查、生物力学、组织学检查观察.[结果]术后第2d～12周两组动物均可正常行走;术后24h力学检测示两种固定方法无显著性差异;随着时间的延长,骨缺损无短缩;X线及组织学检查示复合材料组钛棒周围有成骨现象,扫描电镜见复合材料内有骨长入.[结论]BMG颗粒/PMMA复合材料固定假体时显示出可靠的力学性能及诱导成骨能力,将可能使其成为一种新的假体固定方法.     

Long-term effects of intraarticular cobalt-chrome alloy wear particles in rats

The long-term effects of cobalt-chrome alloy prosthesis wear particles were studied using intraarticular injection of particles into rat knees and killing the rats at regular periods from 1 week to 2 years following injection. The initial response was synovial ulceration, macrophage infiltration, and necrosis. A transient lymphocyte response was present at 1 week. Fibrosis of the subsynovium occurred subsequently at the sites of necrosis. A semiquantitative assessment of the number of particles and macrophages in the synovium demonstrated that the distribution of particles did not alter during the period from 1 week to 1 year. The macrophage response decreased between 1 and 2 weeks and then remained constant for 1 year. No tumors developed. This study emphasizes that cobalt-chrome wear particles and the associated macrophage response persist in the tissues for up to 2 years. The findings are relevant to the effects of wear of all designs of cobalt-chrome alloy prostheses.     

磨损颗粒体内诱导血管内皮生长因子的表达

[目的]研究植骨气囊模型体内血管内皮生长因子(VEGF)的表达及变化规律,探讨其在人工关节无菌性松动发生过程中的作用。[方法]建立人工关节无菌性松动小鼠植骨气囊模型,在实验组小鼠气囊内注入磨损颗粒悬浮液,对照组气囊内注入生理盐水,分别于植骨后1、2、3周分批处死小鼠,取囊壁连同颅骨片组织行HE染色观察囊壁炎症反应、骨片边缘溶解情况,半定量RT-PCR及免疫组织化学染色法观察VEGF基因及蛋白表达量的变化。[结果]接受磨损颗粒的实验组在各时间点VEGF基因表达量及阳性细胞率均明显高于对照组(P<0.05),其中以2周时表达量最高(P<0.05);且实验组炎症反应、骨片边缘溶解情况及微血管数量也相应地明显于对照组。[结论]磨损颗粒在体内可以诱导VEGF的表达,VEGF在假体周围微血管的生成、炎性细胞浸润及骨溶解中起重要作用。     

Cobalt and chromium exposure affects osteoblast function and impairs the mineralization of prosthesis surfaces in vitro

Cobalt (Co) and chromium (Cr) ions and nanoparticles equivalent to those released through tribo‐corrosion of prosthetic metal‐on‐metal (MOM) bearings and taper junctions are detrimental to osteoblast activity and function in vitro when examined as individual species. Here we examined the effects of Co²⁺:Cr³⁺ and Co²⁺:Cr⁶⁺ combinations on osteoblast‐like SaOS‐2 cellular activity, alkaline phosphatase (ALP) activity and mineralization to better reflect clinical exposure conditions in vivo. We also assessed the effect of Co²⁺:Cr³⁺ combinations and Co:Cr nanoparticles on SaOS‐2 cell osteogenic responses on grit‐blasted, plasma‐sprayed titanium‐coated, and hydroxyapatite‐coated prosthesis surfaces. Cellular activity and ALP activity were reduced to a greater extent with combination treatments compared to individual ions. Co²⁺ and Cr³⁺ interacted additively and synergistically to reduce cellular activity and ALP activity, respectively, while the Co²⁺ with Cr⁶⁺ combination was dominated by the effect of Cr⁶⁺ alone. Mineralization by osteoblasts was greater on hydroxyapatite‐coated surfaces compared to grit‐blasted and plasma‐sprayed titanium‐coated surfaces. Treatments with Co²⁺:Cr³⁺ ions and Co:Cr nanoparticles reduced the percentage mineralization on all surfaces, with hydroxyapatite‐coated surfaces having the least reduction. In conclusion, our data suggests that previous studies investigating individual metal ions underestimate their potential clinical effects on osteoblast activity. Furthermore, the data suggests that hydroxyapatite‐coated surfaces may modulate osteoblast responses to metal debris. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1663–1670, 2015.     

Tissue response in relation to type of wear particles around failed hip arthroplasties

To establish the types of wear particles and associated tissue response around human prostheses the periprosthetic tissues around 50 hip arthroplasties revised for aseptic loosening of one or more components were examined by light microscopy, transmission electron microscopy, and energy-dispersing x-ray microanalysis. The tissues around cementless metal-on-bone and ceramic-on-ceramic prostheses contained few or no prosthesis wear particles. The tissues around metal-on-metal prostheses contained large numbers of metal particles and large numbers of macrophages, and occasional multinucleate giant cells. The tissues around cemented metal-on-polyethylene prostheses often contained large numbers of small and large polyethylene particles, variable numbers of cement particles, and occasional metal particles. Large numbers of macrophages and multinucleate giant cells were frequently seen in these tissues. Lymphocytes were occasionally seen in association with metal particles. Ultrastructural studies of the periprosthetic tissues confirmed the phagocytosis of submicroscopic wear particles by macrophages. Varying degrees of degenerative change in macrophages were seen in association with phagocytosis of metal particles. Large numbers of cytolysosomes were seen in cells in association with the accumulation of wear particles.     

Tibiofemoral force following total knee arthroplasty: comparison of four prosthesis designs in vitro.

Despite ongoing evolution in total knee arthroplasty (TKA) prosthesis design, restricted flexion continues to be common postoperatively. Compressive tibiofemoral force during flexion is generated through the interaction between soft tissues and prosthesis geometry. In this study, we compared the compressive tibiofemoral force in vitro of four commonly used prostheses: fixed-bearing PCL (posterior cruciate ligament)-retaining (PFC), mobile-bearing posterior-stabilized (PS), posterior-stabilized with a High Flex femoral component (HF), and mobile-bearing PCL-sacrificing (LCS). Fourteen fresh-frozen cadaver knee joints were tested in a passive motion rig, and tibiofemoral force measured using a modified tibial baseplate instrumented with six load cells. The implants without posterior stabilization displayed an exponential increase in force after 90 degrees of flexion, while PS implants maintained low force throughout the range of motion. The fixed-bearing PFC prosthesis displayed the highest peak force (214 +/- 68 N at 150 degrees flexion). Sacrifice of the PCL decreased the peak force to a level comparable with the LCS implant. The use of a PCL-substituting post and cam system reduced the peak force up to 78%, irrespective of whether it was a high-flex or a standard PS knee. However, other factors such as preoperative range of motion, knee joint kinematics, soft tissue impingement, and implantation technique play a role in postoperative knee function. The present study suggests that a posterior-stabilized TKA design might be advantageous in reducing soft tissue tension in deep flexion. Further research is necessary to fully understand all factors affecting knee flexion after TKA.     

Fixation of trapezial implants in a trapeziometacarpal total joint prosthesis tested in a model of porcine bone

Abstract

High aseptic loosening rates have been reported in total joint prostheses of the carpometacarpal joint of the thumb, particularly in the trapezial component. The primary fixation of new implants may be tested in cadaver bones, but the anatomy of the pig is in many ways similar to that of the human, so we compared the central carpal bone from the forefoot of 6-month-old pigs, which has a saddle joint surface similar to the trapezium, to the trapezium in patients with carpometacarpal osteoarthritis. The mean (SD) bone mineral density of the 13 pig forefoot bones was 0.88 (0.12) g/cm² compared with 0.63 (0.16) g/cm² in the 31 human trapeziums. The measured size of the porcine bones was slightly larger than that of the human trapeziums. The similarity in form, size, and bone mineral density means that the central bone of the forefoot of 6-month-old pigs may be used for fixation tests in trapezial implants.