Post-synovectomy changes in the articular cartilage

Summary Synovectomy of the left knee was performed in 37 immature rabbits, using the right knee for control. In the first set of experiments the articular cartilage was examined at weekly intervals for 8 weeks following the operation, paying particular attention to the metachromatic changes in the ground substance of the cartilage. In the second set of experiments, restoration of synovium was examined. In the third and fourth set of experiments, the uptake of S³⁵ by the cartilage was assessed using autoradiography and densitometry. In the fifth set of experiments, alterations in S³⁵ uptake by the chondrocitic cells of the cartilage were studied by electron microscopy.We found that lesions in the cartilage were reversible and were dependent on restoration of the synovium. We believe these experiments demonstrate the importance of the synovial fluid in the nourishment of the superficial layers of the articular cartilage of joints.

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Résumé Une synovectomie du genou gauche a été réalisée chez 37 lapins immatures, le genou droit servant de témoin. Dans une première série d'expériences, des changements métachromatiques de la substance fondamentale du cartilage articulaire ont été recherchés chaque semaine pendant les deux mois suivant l'intervention. L'évolution de la synoviale a été suivie dans une deuxième série d'expériences.Dans les 3e et 4e séries, on a étudié la fixation du S³⁵ sur le cartilage par autoradiographie et densitométrie. Enfin, par microscopie électronique, dans la 5e série, on a cherché à mettre en évidence des modifications de la fixation du S³⁵ par les chondrocytes.Il semble que les lésions du cartilage sont réversibles, en fonction de l'évolution de la synoviale. De l'avis des auteurs, ces expériences démontrent l'importance du rôle du liquide synovial dans l'alimentation des couches superficielles du cartilage articulaire.

     

膝关节软骨损伤的外科治疗进展

关节软骨损伤后,软骨缺损通常缺乏自行修复能力,要求外科修复。传统外科治疗软骨损伤包括关节镜下冲洗清理术、微骨折术、自体骨软骨移植术、异体骨软骨移植术和自体软骨细胞移植等方法。关节冲洗清理术去除了关节内致痛因素,操作简单,应用广泛,早期疗效确切。微骨折术及自体骨软骨移植对小面积的软骨缺损修复较为理想,然而远期临床观察发现钻孔渗透修复的纤维软骨会降低微骨折术后疗效,相对于重建负重区关节面完整性自体骨软骨移植更具有优势。自体软骨细胞移植及异体骨软骨移植适用于更大面积的软骨缺损,异体骨软骨移植术后存活率受到局部排斥反应影响,从而降低了远期疗效。软骨组织工程技术可最大限度地提高自体软骨细胞移植的修复质量,实现修复组织接近透明软骨,但对于累及软骨下骨板、反应性骨水肿、严重骨量丢失或下肢轴线不良具有局限性。近年来许多新技术陆续应用于软骨损伤治疗领域,创伤小、操作简便、恢复快、疗效好、花费低、多技术联合应用的外科修复技术将会成为未来的治疗软骨损伤的重要手段。目前如何提高软骨修复质量,更具抗压、耐磨性,仍亟待解决。     

冷冻保存对软骨细胞存活率及代谢活性的影响

目的了解各种冷冻保存方法对软骨细胞的存活率和代谢活性的影响，寻找满意的软骨组织冻存方法。方法采用梯度慢速降温法和连续慢速降温法对兔关节软骨进行低温冷冻保存处理，通过荧光染色及^35SO4摄入率了解冻存后软骨细胞的存活率和代谢活性。结果采用梯度降温法的软骨细胞存活率为61％，显著高于连续降温法；冷冻保存对软骨细胞的代谢活性有一定的影响．但与对照组的差异并无统计学意义。结论梯度降温法较传统保存方法能显著提高冷冻保存后软骨细胞的存活率，并能维持软骨细胞的代谢活性，是理想的关节软骨冷冻保存方法。     

肢体缺血再灌注后MMP-3在关节软骨中的表达

目的:了解肢体缺血再灌注后关节软骨内基质金属蛋白酶3(matrixmetalloproteinase- 3,MMP- 3)的表达情况。方法:35只成年健康新西兰大白兔,体重为(3. 0±0 . 5 )kg ,随机分为7组,行左侧后肢缺血8h(右侧为对照) ,于再灌注后1、3d及1、2、4、8和12周取膝关节胫骨平台软骨组织,石蜡切片,免疫组化SP法检测关节软骨内MMP -3的表达。结果:肢体缺血再灌注早期,MMP -3在关节软骨出现强阳性表达,肢体缺血再灌注后3d组阳性细胞较对照侧明显增多,至2周组达峰值(P <0 . 0 1) ,之后逐渐回落,12周组仍高于对照侧(P <0 . 0 5 )。结论:肢体缺血再灌注后,关节软骨内合成并分泌了MMP 3,在软骨基质的降解中发挥重要作用。     

修复关节软骨大面积缺损的实验研究

目的 比较和评价筋膜软骨细胞和骨膜、关节软骨移植修复关节软骨大面积缺损的能力和生物特性。方法 用冻存和新鲜的异体筋膜上培养的软骨细胞、骨膜和关节软骨移植修复大面积关节软骨缺损,通过大体标本、光学显微镜、扫描和透射电镜、放射身显影、微量元素和柱层析氨基酸定量测定、一氧化氮含量测定等多种观察方法进行评价。结果 新鲜和冻存的筋膜软骨细胞移植在结构、形成新的软骨细胞能力、代谢活性方面均优于游离软骨细胞移植     

An experimental study on transplantation of articular cartilage

Summary Behaviour and fate of the transplanted articular cartilage were studied in 180 adult rabbits, using the scanning electron microscope, histological staining and autoradiographic examination.The junction between the host cartilage and the transplanted cartilage was covered with thin connective tissue layers which extended from the edges 4 weeks after transplantation.After the 24th week of transplantation the cartilage tissue appeared to be degenerating at the periphery of the graft.However, in the middle portion of the graft surviving cartilage cells were observed using ³⁵S autoradiography.

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Résumé Comportement et évolution du cartilage articulaire transplanté ont été étudiés chez 180 lapins adultes par microscopie électronique, colorations histologiques et autoradiographies.Quatre semaines après la transplantation, une fine couche de tissue conjonctif qui s'étend depuis les bords recouvre la jonction entre le cartilage du receveur et le cartilage transplanté.Vingt-quatre semaines après la transplantation, le tissu cartilagineux commence à dégénérer à la périphérie du greffon. Cependant, à la partie centrale de celuici, des cellules cartilagineuses survivantes peuvent être mises en évidence grâce à l'autoradiographie au S³⁵.

     

关节软骨修复与细胞因子

关节软骨损伤后的修复非常有限，其对创伤、炎症的反应是由软骨细胞、滑膜组织分泌或关节液中含有的细胞因子所介导的。随着现代分子生物学的发展，人们已发现多种细胞因子参与并调节软骨的生长过程，对软骨损伤的修复起积极的促进作用。下面就近年来较受国内外学者关注的几种细胞因子与软骨损伤修复的关系作一综述。     

研究在体关节软骨营养来源的动物模型

目的 建立局部阻断关节软骨营养的动物模型.方法 将40只5月龄雄性新西兰大白兔随机分5组:保持软骨的关节液营养和软骨下骨营养组(Control组,n=8);假手术对照组(Sham组,n=8);阻断软骨的关节液营养组(DNSF组,n=8);阻断软骨的软骨下骨营养组(DNBM 组,n=8);阻断软骨的关节液和软骨下骨营养组(DNSY+ DNBM组,n=8).术后2周每组随机取3只(6膝),关节腔内注射入墨水,自由活动1d,处死动物,观察内植物的阻断效果;术后4周每组5只(10膝),过量麻醉处死动物,取出膝关节,进行大体评分,并对软骨组织进行组织学评分,免疫组织化学染色.结果 术后2周关节腔内墨水未渗入内植物与骨软骨间隙,提示阻断效果确切;术后4周,大体研究和组织学研究提示,与Control组比较,DNSF组软骨退变明显(P＜0.01),DNBM组软骨未见明显退变(P＞0.01);与DNBM组比较,DNSF组软骨退变明显.结论成功建立局部阻断兔关节软骨各种营养途径的动物模型;失去关节液的营养后,关节软骨表现出早期退变迹象.     

Repairing articular cartilage defects with tissueengineering cartilage in rabbits

Objective: To investigate the effect of cancellous bone matrix gelatin ( BMG ) engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods: Chondrocytes were seeded onto three-dimensional cancellous BMG and cultured in vitro for 12 days to prepare BMG-chondrocyte complexes. Under anesthesia with 2.5% pentobarbital sodium (1ml/kg body weight), articular cartilage defects were made on the right knee joints of 38 healthy New Zealand white rabbits (regardless of sex, aged 4-5 months and weighing 2. 5-3 kg) and the defects were then treated with 2. 5% trypsin. Then BMG-chondrocyte complex ( Group A, n = 18 ), BMG (Group B, n = 10), and nothing (Group C, n = 10) were implanted into the cartilage defects, respectively. The repairing effects were assessed by macroscopic, histologic, transmission electron microscopic ( TEM ) observation, immunohistochemical examination and in situ hybridization detection, respectively, at 2, 4, 8, 12 and 24 weeks after operation. Results: Cancellous BMG was degraded within 8 weeks after operation. In Group A, lymphocyte infiltration was observed around the graft. At 24 weeks after operation, the cartilage defects were repaired by cartilage tissues and the articular cartilage and subchondral bone were soundly healed. Proteoglycan and type II collagen were detected in the matrix of the repaired tissues by Safranin-O staining and immunohistochemical staining, respectively. In situ hybridization proved gene expression of type II collagen in the cytoplasm of chondrocytes in the repaired tissues. TEM observation showed that chondrocytes and cartilage matrix in repaired tissues were almost same as those in the normal articular cartilage. In Group B, the defects were repaired by cartilage-fibrous tissues. In Group C, the defects were repaired only by fibrous tissues. Conclusions: Cancellous BMG can be regarded as the natural cell scaffolds for cartilage tissue engineering. Articular cartilage defects can be repaired by cancellous BMG engineered with allogeneic chondrocytes. The nature of repaired tissues is closest to the normal cartilage. Local administration of trypsin can promote the adherence of repaired tissues to host tissues. Transplantation of allogeneic chondrocytes has immunogenicity, but the immune reaction is weak.     

Computed tomography detects changes in contrast agent diffusion after collagen cross-linking typical to natural aging of articular cartilage

Objective

The effect of threose-induced collagen cross-linking on the mechanical and diffusive properties of cartilage was investigated in vitro. In particular, we investigated the potential of Contrast Enhanced Computed Tomography (CECT) to detect changes in articular cartilage after increased collagen cross-linking, which is an age-related phenomenon.

Methods

Osteochondral plugs (Ø = 6.0 mm, n = 28) were prepared from intact bovine patellae (n = 7). Two of the four adjacent samples, prepared from each patella, were treated with threose to increase the collagen cross-linking, while the other two specimen served as paired controls. One sample pair was mechanically tested and then mechanically injured using a material testing device. Contrast agent [ioxaglate (Hexabrix™)] diffusion was imaged in the other specimen pair for 25 h using CECT. Water fraction, collagen and proteoglycan content, collagen network architecture and the amount of cross-links [hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP) and pentosidine (Pent)] of the samples were also determined.

Results

Cartilage collagen cross-linking, both Pent and LP, were significantly (P < 0.001) increased due to threose treatment. CECT could detect the increased cross-links as the contrast agent penetration and the diffusion flux were significantly (P < 0.05) lower in the threose treated than in untreated samples. The equilibrium modulus (+164%, P < 0.05) and strain dependent dynamic modulus (+47%, P < 0.05) were both significantly greater in the threose treated samples than in reference samples, but there was no association between the initial dynamic modulus and the threose treatment. The water fraction, proteoglycan and collagen contents, as well as collagen architecture, were not significantly altered by the threose treatment.

Conclusions

To conclude, the CECT technique was found to be sensitive at detecting changes in cartilage tissue due to increased collagen cross-linking. This is important since increased cross-linking has been proposed to be related to the increased injury susceptibility of tissue.     

Nonlinear viscoelastic properties of articular cartilage in shear

The strain dependence of the intrinsic viscoelastic properties of the cartilage matrix in shear was investigated. Stress relaxation experiments were performed on bovine articular cartilage at shear strains ranging from approximately 3% to 16%. The tissue was found to exhibit nonlinear strain-dependent viscoelastic behavior, with the nonlinearity occurring primarily in the short-time transient during stress relaxation. In addition, the equilibrium stress was found to fit a quadratic relation with strain. This relationship was noted to be nearly linear with strain from 3% to 16%. The instantaneous stress was seen to be highly nonlinear, and followed a cubic relationship with applied shear strain. Fung's quasilinear theory can be used to describe the stress relaxation response over the range of strains examined when a nonlinear regression is performed to determine an "average" normalized relaxation function. Alternately, strain dependence can be incorporated into the model to describe and predict more accurately the strain-dependent stress relaxation response.     

Ultrastructural changes of TMJ articular cartilage and synovial membrane following occlusal trauma in rabbit

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滑膜关节与关节软骨的形成

膜关节是人体的重要组成部分,虽然数量很少,但是它们都有独特的生物力学结构和功能。近几十年来滑膜关节一直是骨科领域研究的热点,这充分体现了关节对维持人类机体功能和生活质量的重要性,但是目前对胚胎发育过程中滑膜关节的形成机制依然知之甚少。本文对滑膜关节与关节软骨形成机制的研究进展作一综述。     

人关节软骨源性微载体的制备

目的制备一种既能大量扩增人软骨细胞,又能作为细胞支架的人关节软骨源性微载体.方法切取人关节软骨,冷冻干燥后粉碎,筛取150～200μm的软骨颗粒,以质量分数为0.25%的胰蛋白酶37℃消化24 h,加入体积分数为1%的Triton X-100振荡72 h,在倒置相差显微镜下进行观察,并行HE、番红花O染色及软骨蛋白聚糖、Ⅱ型胶原免疫组化染色.将微载体经60Co照射灭菌后与人关节软骨细胞共同培养.结果倒置相差显微镜下可见关节软骨颗粒冻干后呈黄色,形状不一,可呈方形、多角形或不规则形,表面凹凸不平,可见多个陷窝.经胰蛋白酶和Triton X-100处理后,微载体呈淡黄色,关节软骨的基本形态消失,微载体绒毛化,呈绒球状或毛刷状,表面接触面积大幅度增加.微载体与软骨细胞在37℃培养箱中共同培养2 h时即见大量软骨细胞黏附于关节软骨源性微载体上.HE染色显示已无软骨细胞成分;番红花O染色弱阳性,提示仍残留少许糖胺多糖;软骨蛋白聚糖免疫组化染色阴性,提示微载体内软骨蛋白聚糖已被敲除;Ⅱ型胶原免疫组化染色阳性,提示微载体内Ⅱ型胶原仍然存留.结论经胰蛋白酶和Triton X-100处理的关节软骨颗粒,不但脱去了软骨的细胞成分、敲除了软骨蛋白聚糖、使之呈绒球状或毛刷状、增大了表面接触面积,而且保留了对软骨细胞黏附、增殖和再分化起重要作用的Ⅱ型胶原和GAG,经与人关节软骨细胞共培养,证实关节软骨源性微载体与软骨细胞的体外相容性良好.     

关节软骨损伤的修复和重建

关节软骨为透明软骨,其内无神经、血管和淋巴管分布,为单一的结缔组织,软骨细胞存在于软骨陷窝内,主要依靠关节液而获得营养。成年后的关节软骨由于缺乏血供及未分化细胞,损伤后依靠自身修复的能力很低。如何对成人关节软骨的损伤进行修复重建,恢复关节面的完整性,重建关节功能     

The effects of hydrostatic pressure on matrix synthesis in articular cartilage

The direct effects of hydrostatic pressure on matrix synthesis in articular cartilage can be studied independently of the other factors that change during loading. We have found that the influence of hydrostatic pressure on incorporation rates of 35SO4 and [3H]proline into adult bovine articular cartilage slices in vitro depends on the pressure level and on the time at pressure. Pressures in the "physiological" range (5-15 MPa) applied for 20 s or for 5 min could stimulate tracer incorporation (30-130%) during the following 2 h, but higher pressures (20-50 MPa) had no effect on incorporation rates. The degree of stimulation in cartilage obtained from different animals was found to vary; in some animals none was seen. Stimulation also varied with position along the joint. Physiological pressures (5-10 MPa) applied continuously for the 2-h incubation period also stimulated incorporation rates, but pressures greater than 20 MPa always produced a decrease that was related to the applied pressure and that was reversible. These results suggests that the hydrostatic pressure that occurs during loading is a signal that can stimulate matrix synthesis rates in articular cartilage.