在活体上进行关节内压力测量的实验技术

引言有关关节润滑问题的文章论述仅介绍了关于关节外的变化,如:载荷,和总括的运动的测量,但对于润滑的机理讲的并不清楚。在关节润滑中的两个最重要的参数,即液膜的厚度和压力分布状态,并不能由载荷和运动的测量推导得出。McCutchen对猪的弦骨软骨与玻璃之间的摩擦力进行了测量,并推导出液体流出软骨的情况。Walker等〔8〕对人的软骨小型试样与玻璃之间的受压膜性质进行了研究,并得出了液体流入软     

润滑素在肌骨系统损伤修复中的作用

润滑素在肌骨系统各组织如关节软骨、肌腱、滑膜等中广泛表达,其表达与肌骨系统组织结构以及病理状态紧密相关。润滑素在肌骨系统中表现出生物润滑、防止黏连、抑制滑膜细胞增殖和调节炎症等重要功能,对组织损伤修复有重要作用。总结润滑素的表达、调控、结构及其在肌骨系统损伤修复中的作用,为进一步探究润滑素在肌骨系统中的功能和机理以及为肌骨系统损伤的临床治疗提供理论依据。     

基于正交试验的复合型人工滑液摩擦学研究

目的 研究复合滑液三种主要成份透明质酸钠、白蛋白和阿伦磷酸钠对于金属对金属材料界面的润滑性能,为其在关节润滑中的应用提供依据。方法 采用正交试验设计对复合滑液进行配比,借助四球摩擦磨损试验机、粘度测试仪以及光学显微镜,研究了其相应的摩擦学表现。结果 (1)透明质酸钠对滑液的减摩、抗磨以及粘度性能影响最大;(2)由于潜在电化学反应的影响,滑液的抗磨能力并非随白蛋白含量的增加而增加;(3)高含量的治疗性成份阿伦磷酸钠表现出更好的润滑性能。结论 复合滑液部分还原了天然关节液的作用,并具有较好的润滑性能。     

模拟人体环境的人工髋关节疲劳试验机

背景:人工髋关节模拟试验机主要用于评价关节副生物材料的摩擦磨损特性以及验证理论计算结果与实际的吻合程度,而摩擦学试验的结果受试验设备的影响很大。目的:设计新型人工髋关节模拟试验机温度控制和润滑部分,以使试件在试验过程中产生的摩擦机制、磨损形式与实际使用条件下相一致,从而可以准确、可靠地测试人工关节材料的生物摩擦学特性参数。方法:通过铜丝加热并通过PID(比例-积分-微分)控制对温度进行了调节控制,采用滴注式润滑对磨损关节进行了润滑。结果与结论:经实验观察,对试验机温度控制和润滑部分的设计,能够使人工髋关节模拟试验机更真实地模拟人体环境,从而为临床应用提供较为准确可靠的体外试验数据。     

介入治疗导管表面润滑处理研究

介绍了一种用于介入治疗导管表面润滑处理的方法。对润滑涂层的作用原理、涂覆工艺等进行了论述，并讨论了用于润滑处理的聚合物、溶剂的选择及润滑处理后介入治疗导管表面摩擦系数的变化情况。通过生物安全性试验和临床试用，证明了本方法是安全可靠的。     

介入治疗导管表面润滑处理研究

介绍了一种用于介入治疗导管表面润滑处理的方法。对润滑涂层的作用原理、涂覆工艺等进行了论述，并讨论了用于润滑处理的聚合物、溶剂的选择及润滑处理后介入治疗导管表面摩擦系数的变化情况。通过生物安全性试验和临床试用，证明了本方法是安全可靠的。     

颞下颌关节的观测

本文在２０９具成年标本上对颞下颌关节的下颌窝、下颌头、关节盘及关节囊进行了观测;对颞下颌关节的运动及弹响机制进行了讨论。     

新型关节炎注射液-羧甲基壳聚糖的研究

利用壳聚糖分子 C6 位上羟基与氯乙酸反应制得了水溶性羧甲基壳聚糖 (O- CMC) ,电导法测定羧甲基的取代度为 0 .76。对其进行了溶解性表征及动物造模试验。试验结果表明 O- CMC具有润滑关节 ,有效抑制兔膝关节内成纤维细胞增殖的作用 ,有利于病理性关节软骨的修复 ,对兔类风湿性关节炎有较好的疗效     

天然与人工关节中的摩擦学问题

对当前国内外有关天然和人工关节摩擦学的研究工作进行简要的综述,包括：摩擦学的起源于定义,以及人体生物摩擦学研究的内容;关节润滑分析;MOP、MOM、COC人工关节磨损寿命研究;天然软骨的摩擦学研究;人工关节与宿主骨结合界面的微动摩擦学研究;人工滑液的研究等。文中重点列举了中国关节摩擦学研究者的成果。     

关节的润滑机制(文献综述)

关节经常在很大负荷下运动。但是关节运动时并不费力,几乎没有摩擦。关节的摩擦系数约0.002,而设计最好的金属制件的摩擦系数在0.02以上。金属制件都有磨损,而关节只在病理情况下才出现磨损。可见,研究关节的润滑机制具有     

陶瓷对陶瓷人工髋关节的磨擦界面特征

背景：陶瓷对陶瓷人工髋关节假体在临床上已有一定的应用,在表面磨擦、磨损和润滑方面占有优势,具有很大的研发潜力。 目的：评价陶瓷对陶瓷人工髋关节表面磨擦、磨损和润滑特性。 方法：将金属对超高分子量聚乙烯、金属对金属以及陶瓷对陶瓷人工髋关节假体的磨损界面研究进行分析,了解氧化铝陶瓷材料的结构特点、制备工艺以及磨损参数,并分析陶瓷对陶瓷人工髋关节置换治疗的效果,与其它假体材料进行对比。 结果与结论：①金属对超高分子量聚乙烯人工髋关节抗磨损性能差,使磨损颗粒进入关节和周围组织,造成骨溶解和松动。②金属对金属人工髋关节的磨损性能较金属对超高分子量聚乙烯假体有很大改善,骨溶解的发生率非常少,但由于磨损颗粒可散布于体内各脏器和体液中,使用时要注意避免发生过敏反应和毒性。③体外试验和体内试验证明陶瓷对陶瓷人工髋关节具有良好的摩擦、磨损、润滑性能,临床治疗长期随访结果显示陶瓷对陶瓷人工髋关节假体置换后无磨损颗粒,不会发生骨溶解。对于年龄较小,并且对髋关节活动度有较高要求的患者,陶瓷对陶瓷人工髋关节是治疗的首选。随着陶瓷对陶瓷人工髋关节假体设计和材料学的发展,通过改进假体的机械学特性,提高摩擦界面的耐磨性能和润滑机制,陶瓷对陶瓷人工髋关节假体的远期临床疗效将更加满意。     

Lubrication of the Temporomandibular Joint

Although tissue engineering of the temporomandibular joint (TMJ) structures is in its infancy, tissue engineering provides the revolutionary possibility for treatment of temporomandibular disorders (TMDs). Recently, several reviews have provided a summary of knowledge of TMJ structure and function at the biochemical, cellular, or mechanical level for tissue engineering of mandibular cartilage, bone and the TMJ disc. As the TMJ enables large relative movements, joint lubrication can be considered of great importance for an understanding of the dynamics of the TMJ. The tribological characteristics of the TMJ are essential for reconstruction and tissue engineering of the joint. The purpose of this review is to provide a summary of advances relevant to the tribological characteristics of the TMJ and to serve as a reference for future research in this field. This review consists of four parts. Part 1 is a brief review of the anatomy and function of the TMJ articular components. In Part 2, the biomechanical and biochemical factors associated with joint lubrication are described: the articular surface topology with microscopic surface roughness and the biomechanical loading during jaw movements. Part 3 includes lubrication theories and possible mechanisms for breakdown of joint lubrication. Finally, in Part 4, the requirement and possibility of tissue engineering for treatment of TMDs with degenerative changes as a future treatment regimen will be discussed in a tribological context.     

Calculation of theoretical lubrication regimes in two-piece first metatarsophalangeal prostheses

The key joint of the forefoot during gait is the first metatarsophalangeal joint. It plays an important role in propelling the human form but can be subject to a number of diseases which can lead to its replacement with an artificial joint. Some of these designs of prosthesis employ a two-piece ball and socket arrangement and are available with a range of biomaterial couples including ceramic-on-ceramic, metal-on-metal and metal-on-polymer. Calculation of predicted lubrication regimes applicable to these implant designs was undertaken. Modelling the ball and socket implant as an equivalent ball-on-plane model and employing elastohydrodynamic theory allowed the minimum film thickness to be calculated and in turn the lambda ratio to indicate the lubrication regime. The calculations were undertaken for a 50 to 1500 N range of loading values, a 0 to 30 mm/s range of entraining velocities, and a 3 to 15 mm radius range of sizes. Calculations showed that the ceramic-on-ceramic and metal-on-metal implants could operate under fluid film lubrication, whereas the metal-on-polymer combination operated in the boundary lubrication regime. It was also recognized that manufacturing capabilities are critical to the radial clearances and values of surface roughness that can be achieved, and thus the predicted lubrication regime.     

Protein-mediated boundary lubrication in arthroplasty

Wear of articulated surfaces can be a major lifetime-limiting factor in arthroplasty. In the natural joint, lubrication is effected by the body's natural synovial fluid. Following arthroplasty, and the subsequent reformation of the synovial membrane, a fluid of similar composition surrounds the artificial joint. Synovial fluid contains, among many other constituents, a substantial concentration of the readily adsorbing protein albumin. The ability of human serum albumin to act as a boundary lubricant in joint prostheses has been investigated using a pin-on-disc tribometer. Circular dichroism spectroscopy was employed to follow the temperature- and time-dependent conformational changes of human serum albumin in the model lubricant solution. Effects of protein conformation and polymer surface hydrophilicity on protein adsorption and the resulting friction in the boundary lubrication regime have been investigated. Unfolded proteins preferentially adsorb onto hydrophobic polymer surfaces, where they form a compact, passivating layer and increase sliding friction-an effect that can be largely suppressed by rendering the substrate more hydrophilic. A molecular model for protein-mediated boundary friction is proposed to consolidate the observations. The relevance of the results for in vivo performance and ex vivo hip-joint testing are discussed.     

Biomimetic hydration lubrication with various polyelectrolyte layers on cross-linked polyethylene orthopedic bearing materials

Natural joints rely on fluid thin-film lubrication by the hydrated polyelectrolyte layer of cartilage. However, current artificial joints with polyethylene (PE) surfaces have considerably less efficient lubrication and thus much greater wear, leading to osteolysis and aseptic loosening. This is considered a common factor limiting prosthetic longevity in total hip arthroplasty (THA). However, such wear could be mitigated by surface modification to mimic the role of cartilage. Here we report the development of nanometer-scale hydrophilic layers with varying charge (nonionic, cationic, anionic, or zwitterionic) on cross-linked PE (CLPE) surfaces, which could fully mimic the hydrophilicity and lubricity of the natural joint surface. We present evidence to support two lubrication mechanisms: the primary mechanism is due to the high level of hydration in the grafted layer, where water molecules act as very efficient lubricants; and the secondary mechanism is repulsion of protein molecules and positively charged inorganic ions by the grafted polyelectrolyte layer. Thus, such nanometer-scaled hydrophilic polymers or polyelectrolyte layers on the CLPE surface of acetabular cup bearings could confer high durability to THA prosthetics.     

Soft layered concept in the design of metacarpophalangeal joint replacement implants

The metacarpophalangeal (MCP) joint is crucial for hand function, but the joints are frequently affected by arthritis, leading to pain and disability. Joint replacement implants are used to replace the diseased MCP joint. This paper presents an investigation of applying the soft layered concept in the design of a new MCP joint replacement implant. Analytical methods were used to investigate the minimum film thickness for a novel MCP joint with a soft layer. The effect of load, entraining velocity, radial clearance, radius of the metacarpal head, elastic modulus and thickness of the soft layer were investigated. The soft layered joints show an enhanced predicted film thickness and some evidence of fluid film lubrication that should help to reduce wear rates. It may be beneficial for future MCP joint implant designs to utilise the soft layered joint concept.     

A hypothetical biological synovial fluid for treatment of temporomandibular joint disease

Temporomandibular Joint disorder (TMD) is a common disorder of mandibular motion system with distinct clinicopathological characteristics. TMD may cause to change in the components of synovial fluid, that affects the functions on lubrication and nutrition of cartilage. Boundary lubrication system contributing to the low friction of joint consists of three parts: lubricin, surface-active phospholipids and hyaluronan (HA). Diminishment of lubrication function is thereby implicated as an adverse contributing factor in degenerative joint diseases such as internal derangement, osteoarthrosis. Moreover, mesenchymal stem cells (MSCs) of synovial membrane can be obtained without irreversible damage, are easily expandable with limited senescence. We postulate that biological active components secreted from MSCs are separated and accumulated by gel permeation chromatography, and then we use the ultra-flirtation of serum and biologically active components to reconstruct the biological synovial fluid in order to rehabilitate the boundary lubrication system and the nutrition of cartilage. Further study investigating the components of biological synovial fluid provides with new treatment strategy for TMD.     

Polyurethane unicondylar knee prostheses: simulator wear tests and lubrication studies

Many materials are used as artificial joint bearing surfaces; these include conventional stainless steel or CoCrMo-on-ultra-high molecular weight polyethylene (UHMWPE), CoCrMo on itself and alumina-on-alumina. However, these joints have a limited lifespan resulting in failure of the prosthesis and the need for revision surgery. A number of materials have been introduced recently in an attempt to overcome these problems. Polycarbonate urethane (PU) is a compliant material that can be used as an artificial joint bearing surface which has been developed to mimic the natural synovial joint more accurately by promoting fluid film lubrication. Tribological tests were performed on CoCrMo-on-PU unicondylar knee prostheses to assess their performance in vitro. The wear produced by these components was considerably lower than that found for conventional joints. They also exhibited low friction and operated close to full-fluid film lubrication with viscosities of lubricant similar to those found in patients with arthritis. These tests gave encouraging results for the tribological performance of this material couple for use as an alternative bearing combination.     

Poly(ethylene glycol)/chitosan/sodium glycerophosphate gel replaced the joint capsule with slow-release lubricant after joint surgery

Body fluid is normally the only lubricant after joint replacement surgery, but wear problems have occurred because body fluid has poor lubrication ability. However, traditional lubricant would be diluted by body fluids and then absorbed by the human body. Therefore, an injectable gel with the ability to slow-release lubricant was designed to replace the joint capsule. The proposed gel, poly(ethylene glycol)/chitosan/sodium glycerophosphate (PEG/CS/GP) composite gel was then tested. The tribology results showed that the PEG/CS/GP gel had excellent slow-release properties, especially under pressure, and the PEG played an important role in improving the gel’s rheological and mechanical properties. Moreover, this study revealed that the release solution had a good lubrication effect because the PEG and GP could crosslink via the hydrogen bond effect.