Surface fissures in articular cartilage: effect of pathological changes in synovial fluid

Objective. A unified mathematical model of two different modes of inception of fissures at the surface of articular cartilage in healthy and pathological joints.

Design. The superficial tangential zone of articular cartilage is modeled as a three-phase medium consisting of collagen fibers, matrix, and of infiltrated thin constituent of synovial fluid.

Background. The author’s general mesomechanical concept is applied to the analysis of deterioration of articular cartilage.

Methods. Theoretical analysis based on the results of the author’s preceding paper.

Results. The presented analysis shows that superficial fissures in articular cartilage can also be caused by pathological thinning of synovial fluid.

Conclusions. Whereas in healthy joints the probable cause of creation of fissures at the surface of cartilage was shown to be fast impact loading, in joints with inflammatory synovial fluid the fissures can be caused by plain walking.

Relevance  Appearance of surface fissures in articular cartilage is a serious, still not fully clarified problem that deserves attention.     

软骨损伤后Ⅰ、Ⅱ型胶原蛋白的表达

背景：目前Ⅰ型胶原蛋白与骨关节炎间的关系尚未被完全揭示,Ⅰ型胶原蛋白的表达模式亦未知,缺乏相关的研究来探讨上述问题。目的：观察软骨退变过程中Ⅰ型胶原蛋白表达的模式,为进一步研究Ⅰ型胶原蛋白与骨关节炎间的关系提供参考。方法：10只新西兰大白兔,用手术刀片在兔左下肢股骨滑车凹造一约5 mm长的纵向软骨损伤制备软骨损伤模型。造模后2,6周分别处死5只动物,取软骨损伤部位后制作石蜡切片,免疫组织化学检测损伤周围Ⅰ、Ⅱ型胶原蛋白的表达情况,番红O-快绿染色检测损伤周围软骨的退变情况。结果与结论：免疫组织化学示：造模后2周后即可在软骨损伤周围检测到少量Ⅰ型胶原蛋白,6周后软骨损伤周围的Ⅰ型胶原蛋白有所增加,Ⅱ型胶原蛋白则未见明显改变。番红O-快绿染色示：2,6周软骨损伤周围均未见明显退变。结果表明,Ⅰ型胶原蛋白在骨关节炎早期即有表达,在软骨退变过程中表达逐渐增加,提示与骨关节炎的发生密切相关。     

Propagation of surface fissures in articular cartilage in response to cyclic loading in vitro

Background. Mechanical overloading of synovial joints can damage the articular cartilage surface and may lead to osteoarthritis. However, causal links between mechanical and biological events in cartilage are poorly understood.

Objectives. To test the hypothesis that surface fissures in cartilage can propagate mechanically if the joint surface is subjected to vigorous cyclic loading.

Methods. Thirty-five cartilage-on-bone specimens, 15-mm square, were removed from mature bovine knee and shoulder joints. Specimens were loaded by means of a 9-mm-diameter flat indenter with a beveled edge, and their compressive strength determined. Failure occurred in the cartilage surface at an average stress of 36 MPa. Cartilage fissures were marked with Indian ink, photographed, and their length and width measured using image analysis software. Each damaged specimen was subjected to cyclic loading at 40% of its compressive strength, at 0.5 Hz, for up to 5 h. Fissure length and width were measured at regular intervals. After testing, fissure depth was measured from histological sections, and compared with measurements from damaged cartilage which was not cyclically loaded.

Results. Cyclic loading caused cartilage fissures to increase in length (mean 353%, P<0.01) and width (360%, P<0.01) but not depth. Propagation was rapid at first, but approached equilibrium after several hundred cycles. Rehydration in saline had no effect on fissure length, but width returned to pre-cyclic loading values.

Conclusion. Cartilage fissures can propagate mechanically when a joint surface is subjected to cyclic compressive loading in vitro. The transient opening-up of fissures to form wide surface “wounds” during cyclic loading could be of biological significance if it occurred in living people.Relevance

In living joints, wide open fissures in the cartilage surface could promote degenerative changes in the tissue.     

The critical size of focal articular cartilage defects is associated with strains in the collagen fibers

The size of full-thickness focal cartilage defect is accepted to be predictive of its fate, but at which size threshold treatment is required is unclear. Clarification of the mechanism behind this threshold effect will help determining when treatment is required. The objective was to investigate the effect of defect size on strains in the collagen fibers and the non-fibrillar matrix of surrounding cartilage. These strains may indicate matrix disruption. Tissue deformation into the defect was expected, stretching adjacent superficial collagen fibers, while an osteochondral implant was expected to prevent these deformations.Finite element simulations of cartilage/cartilage contact for intact, 0.5 to 8 mm wide defects and 8 mm implant cases were performed. Impact, a load increase to 2 MPa in 1 ms, and creep loading, a constant load of 0.5 MPa for 900 s, scenarios were simulated. A composition-based material model for articular cartilage was employed.Impact loading caused low strain levels for all models. Creep loading increased deviatoric strains and collagen strains in the surrounding cartilage. Deviatoric strains increased gradually with defect size, but the surface area at which collagen fiber strains exceeded failure thresholds, abruptly increased for small increases of defect size. This was caused by a narrow distribution of collagen fiber strains resulting from the non-linear stiffness of the fibers. We postulate this might be the mechanism behind the existence of a critical defect size. Filling of the defect with an implant reduced deviatoric and collagen fiber strains towards values for intact cartilage.     

Evaluation of the effect of collagen network degradation on the frictional characteristics of articular cartilage using a simultaneous analysis of the contact condition

Background. Superficial conditions and integrity of collagen network play an important role on the lubrication performance of articular cartilage. In this work, a technique based on the evanescent waves is used for the evaluation of contact condition during friction tests.

Methods. The frictional and superficial characteristics of the normal and degraded articular cartilages with high and low concentration of collagenase were evaluated. The optical apparatus was set in order to decrease the intensity of a light reflected at the interface between a prism and specimens when collagen fibers are found near the interface.

Findings. For all conditions, an increase in the attenuation of reflectance as the friction coefficient increases was observed with reasonable correlation. For the specimens degraded with collagenase, low friction and reduced attenuation of reflectance were observed at the beginning of sliding followed by a gradual increase in both friction and attenuation of reflectance. In comparison to the degraded specimens, normal specimens presented high friction at beginning and low friction at the end of test.

Interpretation. The superficial conditions and the presence of water at the articular surface play an important role in the lubrication of synovial joints. The ability to retain water for degraded specimens is impaired due to the loss of proteoglycan observed in the histological sections and hence, their low friction observed at the beginning of the test is not sustained for a long time. The use of evanescent waves demonstrated to be very useful in the analysis of the contact condition of articular cartilage.     

Conceptual fracture parameters for articular cartilage

BACKGROUND: Superficial cracks can occur in articular cartilage due to trauma or wear and tear. Our understanding of the behaviour of such cracks in a loaded matrix is limited. A notable study investigated the growth of cracks induced in the bottom layer of the matrix. This paper extends existing studies, characterizing the propagation of superficial cracks and matrix resistance under tension at varying rates of loading. METHODS: Cartilage strips with artificially induced superficial cracks were subjected to tensile loading at different loading velocities using a miniature tensile testing device. Load-displacement data, video and still images were recorded for analysis. FINDINGS: The propagation of superficial cracks in articular cartilage does not follow the classical crack tip advance that is characteristic of most engineering materials. Instead, the crack tip exhibited a negligible movement while the side edges of the crack rotated about it, accompanied by matrix stretching and an upward pull (necking) of the bottom layer of the sample. As loading progresses, the crack edges stretch and rotate to assume a position parallel to the articular surface, followed by the final fracture of the matrix at a point just below the crack tip. Using the recorded mechanical data and images, an analogous poroelastic fracture toughness, Kp(Ic)=1.83 MPa.square root mm (SD 0.8) is introduced. INTERPRETATION: It is extremely difficult for a superficial crack to propagate through articular cartilage. This may be because of the energy dissipation from the crack due to the movement and exudation of water, and large stretching of the matrix.     

The influence of lipid-extraction method on the stiffness of articular cartilage

BACKGROUND: One of the known characteristics of osteoarthritis is the loss of articular cartilage lipids. Therefore, it is important to study how lipids influence the functions of the tissue. This can only be done successfully by indirect analysis involving the extraction of lipids and subsequent assessment of the delipidized matrix. Therefore, for accuracy, the procedure for lipid extraction must not induce any other modification in the samples to be assessed. Hence, we compare three rinsing agents and methods in this study. METHODS: Normal and delipidized articular cartilage samples were tested under compressive loading at 4 loading velocities to obtain and compare their stiffness values. FINDINGS: Chloroform rinsing resulted in a 45% decrease in the stiffness of cartilage at low strain-rates (10(-2)/s and 10(-1)/s) on average with a corresponding increase of 55% at higher strain-rate of 10/s relative to the normal. Ethanol rinsed cartilage exhibited a corresponding decrease of 40% at the low strain-rates while exhibiting an increase of about 20% at the highest loading rates. Propylene glycol rinsing resulted in a decrease of approximately 20% in stiffness, while an increase of up to 5% at high rates of loading. INTERPRETATION: The loss of lipids modifies the stiffness of articular cartilage at all loading rates. The relatively larger deviation of the stiffness of chloroform-rinsed samples relative to the normal is probably a consequence of the drying process involved in rinsing protocol. It is probable that the results of milder rinsing agents, used without vacuum drying, are more reflective of physiological delipidization effects on the tissue. Consequently, we recommend propylene glycol and its associated protocol for extracting lipids from articular cartilage.     

High frequency acoustic parameters of human and bovine articular cartilage following experimentally-induced matrix degradation.

Matrix degradation and proteoglycan loss in articular cartilag eare features of early osteoarthritis. To determine the effect of matrix degradation and proteoglycan loss on ultrasound propagation in cartilage, we used papain and interleukin-1alpha to degrade the matrix proteoglycans of human and bovine cartilage samples, respectively. There is also minor collagen alteration associated with these chemical degradation methods. We compared the speed of sound and frequency dependent attenuation (20-40 MHz) of control and experimental paired samples. We found that a loss of matrix proteoglycans and collagen disruption resulted in a 20-30% increase in the frequency dependent attenuation and a 2% decrease in the speed of sound in both human and bovine cartilage. We conclude that the frequency dependent attenuation and speed of sound in articular cartilage are sensitive to experimental modification of the matrix proteoglycans and collagen. These findings suggest that ultrasound can potentially be used to detect morphologic changes in articular cartilage associated with the progression of osteoarthritis.     

低频脉冲超声干预膝骨关节炎模型兔关节软骨及滑膜水通道蛋白3的表达

背景:研究表明,低频脉冲超声能促进全层关节软骨缺损修复,延缓实验性早期骨关节炎的病变进展。水通道蛋白3存在于关节软骨及滑膜上,并在骨关节炎的发病机制中发挥重要作用。目的:探讨低频脉冲超声对实验性膝骨关节炎兔关节软骨及滑膜水通道蛋白3表达的影响。方法:成年新西兰兔左后膝关节用管型石膏固定于伸直位制动6周制备实验性兔膝关节骨关节炎模型,造模成功后随机分为两组:实验组予以低频脉冲超声治疗(频率为1MHz,功率为2.0W),1次/d,15min/次;对照组不接受超声治疗。分别于治疗后2,4,8周,采用免疫组织化学方法观察兔关节软骨及滑膜水通道蛋白3的表达。结果与结论:随着造模后时间的延长,各组兔关节软骨及滑膜水通道蛋白3的表达均有所增加;与对照组比较,实验组兔关节软骨及滑膜水通道蛋白3表达明显降低(P<0.01)。说明低频脉冲超声能降低实验性兔膝骨关节炎关节软骨及滑膜水通道蛋白3的表达,从而缓解关节肿胀,延缓软骨及滑膜的退变,具有软骨及滑膜保护作用。     

The morphology and selected biological properties of articular cartilage

The purpose of this article is to present the current state of knowledge regarding the structure and functions of articular cartilage. Articular cartilage is constructed with hyaline cartilage tissue. It is composed of chondrocytes located in lacunae and the extracellular matrix. The chondrial matrix contains water, collagen, proteglycans, non-collagenous matrix proteins, and lipids. Articular cartilage is devided into four zones - superficial, intermediate, deep, and calcified - on the basic of morphology, the orientation of collagen fiber, and the proteoglycan content. The dominant collagen of this tissue is Type II collagen, which, together with smaller quantities of other collagens (i.e. Types IX and XII), forms a network of fibers, with large, aggregating proteoglycans and smaller, non-aggregating proteoglycans. Proteoglycans are proteins that contain covalently attached glycosaminoglycans (GAGs), with water between them. The large aggregating proteoglycans, called "aggrecans", form aggregates that bind hyaluronic acid, and together with collagen they are responsible for the mechanical properties of cartilage. The smallnonaggregating proteoglycans, decorin and fibromodulin, limit the formation of collagen fibres. Other proteins in the cartilage matrix - chondrocalcin and the N-propetide of Type II collagen - participate in fiber formation. Yet other proteins - chondronectin, fibronectin, vitronectin and thrombospondin - take part in the interaction between the chondrocytes and the matrix. Cartilage oligomeric matrix protein (COMP) prevents the vascularization of the cartilage and, perhaps, is responsible for the repair process. The proteins known as Cart-1 and CEP-68 participate in chondrogenesis, while tenascin and Mgp are considered to be cartilage calcification inhibitors. Apart from the structural elements, chondrocytes produce substances that fulfill purely physiological functions: enzymes and cytokines. The enzymes - which include metalloproteinases, adamalysins, serine and cysteine proteases and their inhibitors - participate in cartilage matrix reconstruction. The cytokines - IL-1, TNF-alfa, IL-6, IL-8, and LIF - stimulate the chondrocytes to produce an increased amount of enzymes, while IL-4 inhibits this process. Human articular chondrocytes exibit the constitutive expression of class I molecules of the major histocompatibility complex (MHC), molecules regulating the activation of the complement, and after activation (e.g. under the influence of IFN-alfa, IL-1, TNF-a or in the course of arthritis), also MHC class II and ICAM-1 intracellular adhesion molecules. Numerous studies have shown that chondrocytes also have tissue-specific antigens, which induce the production of antibodies in patients with cartilage grafts, as well as those with rheumatoid arthritis and osteoarthritis. Some of these antibodies react with type II collagen, others are directed against other proteins i.e. anchorin CII and CH65. the role of these diverse molecules, which are present in cartilage cells and separated from the immune system by the matrix, remains unclear.     

正常关节软骨和骨关节炎关节软骨细胞中血管活性肠肽表达的比较

背景:神经肽的发现给骨关节炎的治疗带来了新的希望,但神经肽的表达与骨关节炎发病以及软骨退变程度的关系尚不清楚。目的:观察血管活性肠肽在正常关节软骨和不同退变程度骨关节炎软骨中的表达,以及血管活性肠肽表达与骨关节炎发病及软骨退变程度的关系。方法:选取2007-03/11中南大学湘雅医院骨科进行关节置换的骨关节炎患者的关节软骨标本26个,选取因外伤行截肢的膝关节软骨或股骨颈暴力骨折的股骨头正常关节软骨标本10个为对照,根据大体观察凿取正常和骨关节炎不同退变程度软骨块50个,再根据关节软骨改良Mankin病理评分法进行分组,采用免疫组织化学染色检测软骨组织中血管活性肠肽的表达和分布。结果与结论:各关节软骨中均可见到血管活性肠肽阳性神经纤维,正常关节软骨中血管活性肠肽的表达明显高于骨关节炎关节软骨(P<0.05)。且血管活性肠肽表达与软骨改良Mankin病理评分呈负相关(r=-0.896,P<0.05)。说明血管活性肠肽低表达与关节软骨退变程度、骨关节炎病程进展有关,可能是关节软骨退变、骨关节炎发病的机制之一。     

X型胶原在膝骨关节炎软骨中的表达

目的观察膝骨关节炎患者关节软骨中X型胶原的表达特征,探讨X型胶原在骨关节炎疾病进展中的作用。方法取18例膝骨关节炎患者和13例正常对照者的关节软骨。以Northern杂交、RT-PCR和Western杂交,分别检测各组样品X型胶原mRNA和蛋白水平的表达情况。结果 Northern杂交与RT-PCR的结果均显示膝骨关节炎的X型胶原表达有显著升高。Western杂交发现膝骨关节炎患者软骨基质中X型胶原的含量上升(P<0.01)。但分析mRNA和蛋白水平的变化趋势,未能发现它们之间存在明确的相关性(P>0.05)。结论膝骨关节炎患者的X型胶原表达明显增加,这可能促使基质组分发生改变,从而加速了骨关节炎的进展。     

Ⅱ型胶原海绵填充材料修复兔关节软骨缺损

背景修复关节软骨缺损一直是骨科医师致力解决的难题,以前采用自体软骨膜、骨膜或异体骨软骨片移植,但存在供体来源有限、固定困难,以及出现软骨内骨化、软骨下骨与修复性软骨的分层现象等.Ⅱ型胶原是软骨基质的主要成分,对关节软骨缺损的修复应有一定的作用.目的探讨Ⅱ型胶原海绵对修复关节软骨缺损的效果.设计随机对照的实验研究.地点和材料实验地点为广州市创伤外科研究所.材料普通级成年雄性纯种新西兰兔24只48膝,体质量(2.29±0.25)kg,标准饲料分笼喂养.干预在股骨滑车面钻孔为直径5 mm、深3 mm的全层关节软骨缺损,按随机数分为填充组(左膝关节缺损部位植入Ⅱ型胶原海绵)和对照组(右膝关节缺损部位作为空白对照).主要观察指标术后12周内,每双数周对缺损修复情况行大体形态和组织学观察.结果10～12周,对照组缺损区由白色、质软、按压无阻抗的组织修复,修复组织仍低于周围关节面,边界仍清晰可辨,组织学以类似炎症反应的机制修复缺损,最终以透明变性的纤维组织的增生来填补缺损部位;填充组缺损区由半透明状、质韧光滑有光泽,按压有阻抗并有弹性的组织修复,修复组织与周围软骨外形上已基本相似,不易区分,组织学未见有炎症反应的过程,内骨组织和软骨组织增生活跃,并可见大量类骨组织和骨小梁形成,新生软骨和周围软骨组织融合,并与周围组织连接.Ⅱ型胶原对关节软骨缺损的修复有明显的促进作用,修复结果接近正常软骨.结论自行研制的高纯度Ⅱ型胶原海绵,对关节软骨缺损具有良好的促进修复作用,且组织相容性好,无明显的毒副作用.     

Immunohistochemical detection and immunochemical analysis of type II collagen degradation in human normal, rheumatoid, and osteoarthritic articular cartilages and in explants of bovine articular cartilage cultured with interleukin 1.

Articular cartilage destruction and loss of function in arthritic diseases involves proteolytic degradation of the connective tissue matrix. We have investigated the degradation of cartilage collagen by developing immunochemical methods that permit the identification and analysis of type II collagen degradation in situ. Previously, a technique to specifically identify type II collagen degradation in situ in articular cartilage did not exist. These methods utilize a polyclonal antiserum (R181) that specifically reacts with unwound alpha-chains and CNBr-derived peptides, alpha 1(II)CB11 and alpha 1(II)CB8, of human and bovine type II collagens. The experimental approach is based on the fact that when fibrillar collagens are cleaved the helical collagen molecule unwinds, exposing hidden epitopes. Here we demonstrate the use of R181 in studying type II collagen degradation in bovine articular cartilage that has been cultured with or without IL-1 and in human normal, rheumatoid, and osteoarthritic articular cartilages. Compared to cartilages either freshly isolated or cultured without IL-1, bovine cartilage cultured with IL-1 for 3-5 d showed an increase in both pericellular and intercellular immunohistochemical staining. Extracts of these cartilages contained type II collagen alpha chains that were increased in amount after culture with IL-1 for 11 d. In addition, culture with IL-1 resulted in the appearance of alpha chain fragments of lower molecular weight. All human arthritic tissues examined showed areas of pronounced pericellular and territorial staining for collagen degradation as compared with non-diseased tissues, indicating that chondrocytes are responsible in part for this degradation as compared with non-diseased tissues. In most cases rheumatoid cartilage was stained most intensely at the articular surface and in the deep and mid-zones, whereas osteoarthritic cartilage usually stained more in the superficial and mid-zones, but less intensely. Distinct patterns of sites of collagen degradation reflect differences in collagen destruction in these diseases, suggesting possible different sources of chondrocyte activation. These experiments demonstrate the application of immunological methods to detect collagen degradation and demonstrate an increase of collagen degradation in human arthritides and in IL-1-treated viable bovine cartilage.     

低频脉冲超声干预膝骨关节炎模型免关节软骨及滑膜水通道蛋白3的表达

背景：研究表明,低频脉冲超声能促进全层关节软骨缺损修复,延缓实验性早期骨关节炎的病变进展。水通道蛋白3存在于关节软骨及滑膜上．并在骨天节炎的发病机制中发挥重要作用。目的：探讨低频脉冲超声对实验性膝骨关节炎兔关节软骨及滑膜水通道蛋白3表达的影响。方法：成年新西兰兔左后膝关节用管型石膏固定于伸直位制动6周制备实验性兔膝关节骨关节炎模型,造模成功后随机分为两组：实验组予以低频脉冲超声治疗（频率为1MHz,功率为2.0w）,1次/d．15min/次：对照组不接受超声治疗。分别于治疗后2,4,8周,采用免疫组纵化学方法观察兔关节软骨及滑膜水通道蛋白3的表达。结果与结论：随着造模后时间的延长,各组兔芙节软骨及滑膜水通道蛋白3的表达均有所增加;与对照组比较,实验组兔哭节软骨及滑膜水通道蛋白3表达明显降低（P〈0.01）。说明低频脉冲超声能降低实验性兔膝骨关节炎关节软骨及滑膜水通道蛋白3的表达,从而缓解关节肿胀,延缓软骨及滑膜的退变,具有软骨及滑膜保护作用。     

关节软骨损伤后体外培养软骨细胞的功能变化

背景：关节软骨损伤可以影响软骨细胞功能,诱发创伤性骨关节炎。目的：观察关节软骨损伤后体外培养的软骨细胞功能的变化。方法：通过酶消化法分离培养高能量、低能量撞击后和正常兔膝关节透明软骨细胞,观察创伤能量对软骨细胞生存能力的影响;检测软骨细胞合成蛋白多糖和Ⅱ型胶原能力,检测细胞中白细胞介素1β和核转录因子κB mRNA表达水平,检测细胞合成白细胞介素1β和基质金属蛋白酶1的表达。结果与结论：高能量和低能量关节软骨损伤后,软骨细胞的存活率下降,原代细胞的贴壁细胞数量减少,贴壁时间延长,生长曲线下移,细胞甲苯胺蓝染色异染反应减弱,Ⅱ型胶原免疫组化染色强度减弱,软骨细胞中白细胞介素1β和核转录因子κB mRNA表达水平上升,细胞培养液中白细胞介素1β和基质金属蛋白酶1的质量浓度升高,其中高能量组效果更为显著（P〈0.05）。说明关节软骨损伤后软骨细胞的功能受到影响,受损程度与创伤强度及炎性细胞因子的表达相关。     

Independent expression of fibril-forming collagens I, II, and III in chondrocytes of human osteoarthritic cartilage.

Normal and osteoarthritic human articular cartilage was investigated by in situ hybridization for expression patterns of the fibrillar collagens type I, II, and III to evaluate phenotypic changes of articular chondrocytes related to the disease. In 11 out of 20 samples, a defined subset of chondrocytes in the superficial and upper middle zone of osteoarthritic cartilage showed significant levels of cytoplasmic alpha 1 (III) mRNA, whereas strong signals of alpha 1 (II) mRNA were found in the upper and lower middle zone, partially overlapping with the zone of alpha 1 (III) mRNA-expressing cells. The extent of type II and III collagen expression depended on the integrity of the extracellular matrix surrounding the chondrocytes, and the location within the articular cartilage. No alpha 1 (I) mRNA was detectable in osteoarthritic original articular cartilage. The alpha 1 (I) probe did, however, reveal signals in pannus-like tissue, osteophytes, and bone cells. In normal articular cartilage, no detectable levels of cytoplasmic mRNA for alpha 1(I), alpha 2 (I), or alpha 1 (III) were seen. Using specific mono- and polyclonal antibodies, we found deposition of type III collagen but hardly any of type I collagen in the superficial zone of osteoarthritic cartilage that is consistent with the in situ hybridization results. These results indicate a phenotypic alteration in a defined subset of chondrocytes in conditions of diseased cartilage, expressing and synthesizing collagen type III independently from type I collagen, but in part simultaneously with type II collagen.     

透明质酸钠对兔创伤性骨关节炎软骨诱导一氧化氮合酶mRNA表达的干预

背景各种关节损伤、关节手术后导致的创伤性骨关节炎较为常见,关节腔注射透明质酸钠已被视为一种治疗骨关节炎的有效手段.目的以前交叉韧带切断的方法建立兔创伤性骨关节炎模型,观察关节腔注射透明质酸钠对其关节软骨中诱导型一氧化氮合酶mRNA表达水平的影响.设计随机对照动物实验.单位武汉大学人民医院骨科.材料实验于2003-04/12在武汉大学人民医院骨科实验室完成.选取清洁级5～6月龄大耳白兔16只,随机数字表法分为透明质酸钠注射组、生理盐水对照组,8只/组.透明质酸钠(上海建华精细生物制品有限公司提供,国药准字2000第366095号).方法①两组均建立创伤性骨关节炎模型.每只兔以氯胺酮1.0 mg/kg体质量麻醉,单侧膝关节行前交叉韧带切断造模.②术后第5周,透明质酸钠注射组患膝关节腔注射质量浓度为10 g/L的透明质酸钠0.3 mL,1次/周,连续5周.生理盐水对照组注射等量生理盐水.③术后10周处死,观察两组股骨内髁关节软骨的大体形态学(0分关节面光滑,色泽正常;1分关节面粗糙,有小的裂隙,色泽灰暗;2分关节面糜烂,软骨缺损达软骨表层或中层;3分关节面溃疡形成,缺损达软骨深层;4分软骨剥脱,软骨下骨质暴露)和组织学病理变化,采用反转录聚合酶链反应方法检测软骨诱导型一氧化氮合酶mRNA的表达情况.主要观察指标①两组股骨髁关节面标本大体观察结果.②两组股骨内髁软骨光镜组织学观察结果.③两组软骨诱导型一氧化氮合酶mRNA的表达.结果实验选取清洁级大耳白兔16只,全部进入结果分析.①两组股骨髁关节面标本大体观察结果解剖显微镜下观察股骨髁关节面病理变化,透明质酸钠注射组软骨退变程度较生理盐水对照组明显减轻.②两组股骨内髁软骨光镜组织学观察结果透明质酸钠注射组见软骨膜变性脱落,表层软骨细胞变性、坏死、排列紊乱,形成糜烂;生理盐水对照组见软骨细胞变性、坏死,排列紊乱,溃疡病变达软骨深层,并见新生的毛细血管和成纤维细胞增生,溃疡底部见纤维组织增生.③两组软骨诱导型一氧化氮合酶mRNA的表达透明质酸钠注射组软骨诱导型一氧化氮合酶mRNA表达量均值为1.09±0.18,生理盐水对照组的表达量均值为1.26±0.23,两组基本相似(P＞0.05).结论关节腔注射透明质酸钠对早期骨关节炎软骨具有修复和保护作用,能有效减轻早期创伤性骨关节炎关节软骨的退变,对诱导型一氧化氮合酶的表达没有下调作用.     

兔骨内高压型膝关节骨性关节炎模型的建立

背景：虽然实验中使用的膝关节骨性关节炎动物模型众多,但研究中医手法作用机制所采用的动物模型应能承受＂动＂的作用并发挥出正常＂动＂产生的效应。目的：确定建立骨内高压型膝关节骨性关节炎动物模型的效果。方法：无菌条件下显露新西兰兔右侧臀部的臀下静脉,右下腹部的股静脉和大隐静脉,结扎并切断;以同样手术显露相应血管但不结扎切断血管的动物及正常组动物作为对照。术后8周末处死所有动物,取动物右膝内侧胫骨平台软骨组织通过大体观察及苏木精-伊红染色、光镜观察软骨组织的结构变化,评估动物模型的造模效果。结果与结论：模型组关节面粗糙、灰黄色,可见明显缺损及骨赘形成,达到初中期变化。假模组关节面粗糙,灰白色无光泽,处于早期变化。正常组关节面光滑,边缘规整,软骨半透明有光泽,无变化。结果提示,通过结扎动物臀下静脉、股静脉及大隐静脉8周后,可形成早中期膝关节骨性关节炎动物模型。     

木瓜蛋白酶诱导大鼠膝早期骨关节炎软骨表面的电镜扫描

背景：木瓜蛋白酶注射建立骨性关节炎动物模型是用于骨关节炎防治研究的常用方法之一。 目的：观察木瓜蛋白酶和L-半胱氨酸混合注射诱导大鼠膝早期骨关节炎进程中扫描电镜下软骨表面形态学变化。 方法：2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸按2∶1比例混匀,取0.15 mL注射至SD大鼠右膝关节腔诱导骨关节炎模型,左膝注射等量生理盐水为对照组,另取2只4膝不做处理为正常对照组,于注射后第2,4,6周后分别使用扫描电镜观察股骨内侧髁关节软骨表面形态学变化。 结果与结论：正常和对照组可见表面分布较均匀的浅坑。木瓜蛋白酶和L-半胱氨酸混合注射2周后大鼠软骨表面出现凹凸不平,皱缩扭曲变形;4周表面变薄,局部出现小裂纹;6周出现深大裂纹,软骨缺损。提示2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸混合注射诱导的早期骨关节炎模型的时间节点可以定在4-6周。