Intra-articular injection of hyaluronan diminishes loss of chondrocytes in a rat immobilized-knee model

Joint immobilization is a useful and common treatment modality in orthopedics. However, it also causes unfavorable outcome such as articular cartilage degeneration. Intra-articular injection of hyaluronan has been accepted as a treatment of osteoarthritis, but its effects on immobilized joint remain to be clarified. Hyaluronan is a polysaccharide, distributed ubiquitously in various tissues. In this study, we examined the effect of hyaluronan on the articular cartilage in immobilized joints. The unilateral knee joints of adult male rats were immobilized at 150 degrees in flexion with an internal plate and screws for 1, 2, 4, 6, 8, 12, or 16 weeks (n = 84). Hyaluronan or saline (50 microl/each injection) was administered intra-articularly on the day of surgery and once a week. The articular cartilage from the medial midcondylar region of the knee was obtained, and divided into non-contact, contact and transitional areas (between the non-contact and the contact areas). In each area, a degree of degeneration was evaluated by histomorphometric grading, and measurements of thickness and number of chondrocytes. Histological grading scores in the hyaluronan group were smaller at 12 and 16 weeks compared with those in the saline group. The thickness of the articular cartilage increased in the transitional area in both groups. The number of chondrocytes in the contact and transitional areas gradually decreased, but their number in the hyaluronan group was greater at 12 and 16 weeks compared with that in the saline group. Hyaluronan showed chondroprotective effects on the articular cartilage in a rat immobilized-knee model.     

T2^*mapping技术评估早期膝关节软骨退变

目的:探讨T2^*mapping技术诊断早期膝关节软骨退变的应用价值。方法:常规MR成像显示关节软骨正常而关节镜诊断软骨退变的65个膝关节,先记录常规MR成像显示关节软骨正常的具体关节面和数量,再记录T2^*mapping诊断为软骨退变的具体关节面和数量并与关节镜结果对照。测量软骨内退变区域T2^*值以及正常区域T2^*值,统计分析两者是否存在差异。结果:65个膝关节,关节镜诊断软骨退变113处,T2^*mapping诊断软骨退变72处,T2^*mapping诊断阳性率63.7%。软骨退变区域的T2^*均值为30±8.1ms,正常区域的T2^*均值为23±5.1ms,差异有统计学意义(t=5.585,P<0.05)。结论:T2^*mapping技术可明显提高MR术前诊断早期软骨退变的阳性率。     

Contrasting alterations of apposed and unapposed articular cartilage during joint contracture formation

OBJECTIVE: To quantify histologic articular cartilage alterations after immobilization, distinguishing between apposed and unapposed sites in an animal model of joint contracture. DESIGN: Experimental controlled trial. SETTING: Laboratory, in vivo study. ANIMALS: Adult male Sprague-Dawley rats (N=128). INTERVENTIONS: One hundred seventeen animals had 1 knee internally immobilized or sham-operated for 2, 4, 8, 16, or 32 weeks. One knee in 11 nonoperated animals served as controls.Main outcome measures On standardized sections, we identified femur and tibia cartilage sites that were apposed or that were unapposed. We quantified 4 characteristics: number of chondrocytes in the superficial and deep cartilage; matrix staining intensity to toluidine blue; surface irregularity of articular cartilage; and thickness of cartilage. RESULTS: Immobilized knees harbored fewer chondrocytes in the superficial cartilage at apposed sites and in the deep cartilage at unapposed sites. Matrix staining decreased only at unapposed sites. Cartilage surface became significantly more irregular at both sites but cartilage thickness remained unchanged. Noncartilaginous tissues appeared only at unapposed sites in the superficial and deep cartilage. CONCLUSIONS: Immobilization led to contrasting patterns of cartilage degeneration at apposed sites compared with unapposed sites. These results suggest distinct pathogenetic pathways for cartilage alterations, possibly through absence of mechanical forces (negative mechanotransduction) at unapposed sites and cyclic pressure at apposed sites. Considering the limited potential for cartilage self-repair, these results support the need for early diagnosis and aggressive mobilization of joints that are developing contractures.     

褪黑素与复方倍他米松对膝骨性关节炎软骨病变的干预

背景:关节软骨组织缺乏血管和神经分布,因此炎性损伤后自我修复能力较差.目的:评估褪黑素和复方倍他米松对骨性关节炎关节软骨病变大鼠的影响.方法:向30只SD大鼠膝关节腔注射木瓜蛋白酶制备膝骨性关节炎模型,其中的20只大鼠采用持续光照的方法建立大鼠去松果体模型,在此基础上,联合应用褪黑素和复方倍他米松治疗其中的10只大鼠.另取10只正常大鼠作对照.治疗4周后,应用ELISA法检测大鼠褪黑素昼夜节律的最高血药浓度时间和最低血药浓度时间时血清褪黑素水平,同时切取股骨髁进行大体观察,之后脱钙制片,行甲苯胺蓝染色,采用Mankin评分评估关节损伤程度.结果与结论:大鼠膝骨性关节炎后,软骨表面凹凸不平,失去光泽;软骨细胞排列紊乱,有明显失染现象,褪黑素水平降低,昼夜节律变化不明显.持续光照后,软骨损伤进一步加重.经褪黑素和复方倍他米松治疗后,大鼠软骨软化现象消失,软骨细胞排列较规则,失染现象减轻,软骨弥散性细胞明显减少.同时,各组甲苯胺蓝染色的Mankin评分比较差异也有显著性意义(P＜0.05).说明褪黑素和复方倍他米松联合应用能够抑制软骨病变的发展.     

不同运动方式引起关节软骨改变的病理研究

目的研究不同方式的运动训练对骨性关节炎关节软骨改变的影响。方法以新西兰白兔 60只为研究对象,管型石膏固定的方法建立 OA动物模型,随机分为制动 4周组（ A组）,制动 8周组（ B组）。从组织形态学方面观察不同运动方式对不同 OA病理分期的作用效果。结果制动 4周时,软骨表面不平滑,部分软骨细胞退变坏死,制动 8周时病变加重,软骨表面纤维化,软骨细胞明显退变并减少。制动可引起软骨退变,但退变关节软骨在运动中有重塑的能力。结论适宜的运动可使 OA关节软骨早期病变逆转,对晚期关节软骨退变只起减轻和延缓作用。     

Arthroscopic evaluation of cartilage degeneration using indentation testing--influence of indenter geometry

BACKGROUND: It has been suggested that the early onset of cartilage degeneration might be detected with a handheld indentation probe during knee arthroscopy, prior to any visible change on the articular surface. Collagen degradation has been considered as the first sign of cartilage degeneration. Therefore, it is important to consider the collagen network as a distinct constituent in the study of arthroscopic evaluation of cartilage degeneration. METHODS: The tip of an arthroscopic probe (indenter) was modeled as rigid and in contact with a cartilage/bone disk of sufficiently large radius to simulate an indentation in a joint. A fibril-reinforced model of cartilage, including streaming potentials and distinct constitutive laws for the proteoglycan matrix and collagen network, was used to determine the contact mechanics of indenter and cartilage. The finite element package ABAQUS was employed to obtain numerical solutions. FINDINGS: A spherical indenter produces a relatively uniform deformation in cartilage, but can easily slide on the articular surface. In contrast, a cylindrical indenter produces great deformation gradients for quick compression rates, but does not slide as easily on the articular surface as the spherical indenter. Small porous and large solid indenters should be used to evaluate the properties of the proteoglycan matrix and collagen network, respectively, in order to minimize or maximize the fluid pressure in the corresponding case. When the collagen network is substantially degraded, the gradients of fluid pressure and deformation are greatly reduced regardless of indenter geometry. INTERPRETATION: The indenter geometry including its porosity is important to the material safety of articular cartilage in indentation and precise evaluation of cartilage degeneration.     

应用生物蛋白胶与胚胎软骨细胞混合移植修复兔膝关节实验性软骨缺损区

背景应用异体软骨细胞移植修复关节软骨缺损的研究较多,但其可引起免疫反应.由于胚胎细胞具有较低的抗原性和较强的增殖能力,期望其能为组织工程研究与应用开辟新的载体材料.目的采用兔胚胎软骨细胞培养移植修复关节软骨缺损,并对其组织形态学进行观察.设计随机分组观察对比实验.单位广西医科大学组织胚胎学试验室.材料孕4周新西兰大白兔1只;成年新西兰大白兔24只,雌雄不限,体质量2～2.5 kg .方法实验于2000-12/2002-06在广西医科大学组织胚胎学试验室完成.在成兔股骨内侧髁作关节软骨缺损模型,实验组采用生物蛋白胶与胚胎软骨细胞相混后,植入兔膝关节实验性软骨缺损区,对照组不做任何处理或单纯用生物蛋白胶移植修补,分别于术后4,8,12周观察关节软骨缺损修复的情况,并按改良Pineda方法对其进行组织学评分,标准为细胞形态、基质染色、表面平整、软骨厚度、宿主结合5项,0分表示正常,分值越高表示改变越严重.主要观察指标①兔膝关节标本大体观察结果.②兔膝关节标本组织学观察结果.③关节软骨组织学半定量计分结果.④关节软骨缺损修复区进行疗效评价结果.结果24只兔均进入结果分析.①兔膝关节标本大体观察结果胚胎软骨细胞+纤维蛋白封闭剂组缺损区颜色接近正常软骨,质韧弹性好,与周围软骨界限消失;纤维蛋白封闭剂组与未处理组始终未愈合,但创面略小,有白色纤维组织充填.②兔膝关节标本组织学观察结果胚胎软骨细胞+纤维蛋白封闭剂组优势组织为透明样软骨,深方为骨组织,表面略凸或平整,基质着色正常,与周围软骨完全结合分界不清,组织中未发现淋巴细胞浸润;纤维蛋白封闭剂组与未处理组为纤维组织,部分有残留明显的凹陷性瘢痕,与周围组织接合或部分接合.③关节软骨组织学半定量计分结果按改良自Pineda方法,12周胚胎软骨细胞+纤维蛋白封闭剂组评分显著低于纤维蛋白封闭剂组和未处理组[(0.50±0.76),(7.88±1.13),(8.13±1.36)分,P＜0.05],而单纯用纤维蛋白封闭剂修补组在4周与未处理组比较有显著性差异(P＜0.05),在8,12周则无差异.④关节软骨缺损修复区进行疗效评价结果12周时胚胎软骨细胞+纤维蛋白封闭剂组完全修复8膝,纤维蛋白封闭剂组不完全修复1膝,未修复7膝,未处理组未修复8膝.结论胚胎软骨细胞移植组所产生的修复组织接近正常软骨组织,明显优于纤维蛋白封闭剂组和未处理组,该方法作为关节软骨缺损修复是可行的.     

Influence of an interpositional spacer on the behaviour of the tibiofemoral joint: a finite element study

BACKGROUND: Interpositional arthroplasty is considered by many surgeons for the treatment of isolated medial compartment osteoarthritis of the knee. In this procedure, an interpositional spacer is inserted into the medial compartment of the joint with no bone resection and no mechanical fixation. Major problems such as implant dislocation, severe pain or need for revision have been reported post-operatively. METHODS: In this study, the kinematics of a knee implanted with an interpositional spacer made of either polyurethane or cobalt-chrome during walking, stair ascent and squatting cycles have been predicted and compared to the normal knee using finite element analysis. In addition, articular cartilage stress histories have been examined to obtain distributions of cumulative stress, a measure of the likelihood of articular cartilage degeneration. FINDINGS: The insertion of a polyurethane interpositional spacer in the medial side of the knee did not affect knee kinematics as compared to the normal knee, but caused an increase of articular cartilage cumulative contact stress exposures in the medial compartment of the joint. The knee implanted with the Co-Cr spacer exhibited similar trends in knee kinematics, however significantly different ranges of motion were observed during some periods of the activity cycles, specifically during the first half of the walking cycle where lower ranges of motion were predicted. In addition, higher articular cartilage cumulative contact stress exposures were observed in both compartments of the knee. In both cases, cumulative contact stress exposures of the tibial articular cartilage were more affected than those of the femoral articular cartilage. INTERPRETATION: These results suggest implant material as an important parameter in the design phase of interpositional spacers.     

大鼠膝关节软骨与不同强度跑台运动的影响

背景:适量的运动是维持正常关节组织形态结构及生理功能的必要条件,过度运动或制动均可导致关节软骨退变。目的:观察不同强度跑台运动对大鼠膝关节软骨的影响。方法:将18只雄性成年Wistar大鼠随机分安静组、低强度运动组、高强度运动组。6周后ELISA法测定血清基质金属蛋白酶3水平,并行蕃红-O染色、基质金属蛋白酶3与Ⅱ型胶原免疫组织化学染色及Mankin评分,反转录聚合酶链反应检测软骨基质金属蛋白酶3的mRNA表达。结果与结论:高强度运动组Mankin评分、血清及软骨中基质金属蛋白酶3表达均显著高于安静组与低强度运动组(P<0.05),基质糖氨多糖及Ⅱ型胶原含量均显著低于安静组与低强度运动组(P<0.05);低强度运动组与安静组差异无显著性意义。说明高强度运动可造成大鼠膝关节软骨退行性变,且软骨运动性损伤可能与基质金属蛋白酶3表达增强有关。     

The reconstruction of defects in articular cartilage using autologous chondrocytes

A defect was artificially created on the joint surface of the distal ends of both femoral bones in 30 rabbits. After digestion of the cartilage fragment, the resulting cells were cultured in vitro and multiplied. The multiplied autologous chondrocytes were implanted at the point of the defect under a periosteum patch in the right knee (group I). The defect in the left knee was covered with periosteum alone (group II). The regenerates obtained in this way were evaluated at 4, 8, and 12 weeks after surgery, macroscopically for even coverage of the surface of the defect and the quantity of regenerate in proportion to the surrounding healthy tissue, microscopically with H + E stain for the nature of the prevalent tissue, integration with the environment, the presence of necrosis, the formation of isogenous groups of cells, and the formation of cracks.
In the macroscopic evaluations at weeks 4, 8, and 12, the presence of regenerate was discovered in group I in approximately the same quantities as in the surrounding cartilage. The group II joints were found to have less satisfactory repair of the lesion.
In the microscopic evaluation, group I was found histologically to have cartilage tissue well integrated with the environment and chondrocytes forming isogenous groups of cells. In group II most of the joints were found to have incomplete or no integration with the surrounding tissue, with necrosis and cracking.
The reconstruction of defects in articular cartilage using autologous chondrocytes and periosteum produced a regenerate macroscopically similar to the surrounding articular cartilage. The results obtained by regeneration of articular cartilage using autologous chondrocyte grafts and periosteum were superior to those obtained with isolated periosteum grafts.     

Finite element analysis of the effect of meniscal tears and meniscectomies on human knee biomechanics

BACKGROUND: Many authors have suggested that the high levels of shear and tensile stresses that appear in the articular cartilage after meniscectomy are partly responsible for cartilage pathologies, such as osteoarthrosis. METHODS: In this paper, we investigate the effect of meniscal tears and meniscectomies on the human knee joint. Solid models of the tibia, femur, menisci and cartilage were generated from MRI images. A three-dimensional finite element model was developed that included the femur, tibia, cartilage layers, menisci and ligaments. The femur and tibia were considered to be rigid, the articular cartilage and menisci to be linearly elastic, isotropic and homogeneous and the ligaments were modelled as hyperelastic. Three different situations were compared: a healthy tibio-femoral joint, a tibio-femoral joint with tears in one meniscus and a tibio-femoral joint after meniscectomy. FINDINGS: The minimal principal stresses corresponding to a compressive load at 0 degrees flexion were obtained for the posterior zone of the medial meniscus and the corresponding region of the articular cartilage. Under an axial femoral compressive load, the maximal contact stress in the articular cartilage after meniscectomy was about twice that of a healthy joint. INTERPRETATION: This fact could partially explain the cartilage damage and degeneration that have been observed after meniscectomy.     

丝素蛋白/羟基磷灰石材料复合骨髓间充质干细胞构建组织工程化软骨

背景：随着组织工程的兴起,软骨损伤的修复可能性显著地提高,但单一的支架材料均不能符合理想支架,有一定的局限性。目的：观察骨髓间充质干细胞复合丝素蛋白/羟基磷灰石构建组织工程化软骨的可行性。方法：体外分离培养骨髓间充质干细胞,并定向诱导成软骨细胞,与丝素蛋白/羟基磷灰石复合培养,构建膝关节胫骨平台全层关节软骨缺损。54只大白兔单侧膝关节全层软骨缺损模型后随机抽签法分为3组,复合组植入细胞-丝素蛋白/羟基磷灰石复合物;材料组植入单纯丝素蛋白/羟基磷灰石,对照组不行任何植入。植入后8,12周CT检查及组织学检查观察软骨缺损修复情况。结果与结论：植入后8周,复合组关节面不平整,关节间隙增大,形成新生类软骨细胞,基质丰富。材料组关节面塌陷,软骨细胞少量增殖。植入后12周,复合组关节面平整,关节间隙如常。大量软骨细胞出现,与周边软骨色泽一样,支架材料完全降解。材料组关节面不平整,软骨细胞不完全充填,支架材料部分降解。对照组未见修复。提示用骨髓间充质干细胞复合丝素蛋白/羟基磷灰石可形成透明软骨修复动物膝关节全层软骨缺损,显示了丝素蛋白/羟基磷灰石材料作为关节软骨组织工程支架材料的良好生物相容性。     

维药买朱尼对关节软骨前炎性因子的影响

背景：骨关节炎病理过程中,白细胞介素1β被认为是促进软骨基质降解和关节软骨破坏的最重要的细胞因之一。目的：观察白细胞介素113在关节软骨中的表达,并观察维药买朱尼对其的影响。方法：将40只SD大鼠随机数字表法随机等分为模型对照组、维药买朱尼组、假手术组、正常对照组。模型对照组和维药买朱尼组采用改良Hulth造模法建立大鼠膝骨关节炎模型,假手术组仅显露膝关节,不切断韧带,不切除内侧半月板。维药买朱尼组建模第2周开始灌胃维药买朱尼10．31mg／（kg·d）,模型组及假手术组大鼠均灌服等量生理盐水,连续4周。结果与结论：模型组软骨退变程度明显重于维药买朱尼组,模型组软骨大体评分及Mankin评分均明显高于维药买朱尼组（P〈0．05）,模型组软骨细胞白细胞介素1β的表达强度亦明显高于维药买朱尼组（P〈0．05）。与正常对照组比较,假手术组软骨大体评分、Mankin评分及软骨细胞白细胞介素1β差异无显著性意义（P〉0．05）。结果说明,维药买朱尼可以抑制关节软骨前炎性因子白细胞介素1β的表达。     

超声评价不同分期的膝关节软骨退行性变

目的探讨超声诊断膝关节软骨退行性变分期的临床价值。方法超声探查40例患者的41个拟行关节镜手术或关节置换术膝关节，均观察其股骨内髁、股骨外髁、股骨滑车正中沟、滑车内侧斜面和滑车外侧斜面，共计205个关节面。超声结果与手术所见对照。结果超声诊断膝关节软骨退行性变（退变）的敏感性、特异性、准确性分别为64．9％、92．0％、76．5％。但对Ⅰ、Ⅱ期的诊断敏感性（46．7％）远远低于Ⅲ、Ⅳ期（75．7％）。结论超声评价膝关节软骨退变具有一定的敏感性和较高的特异性，可作为诊断该病的重要筛查手段。     

髌股关节软骨退变的MRI和关节镜对照研究

目的：以关节镜为标准,确定３Ｄ－Ｖｏｌｕｍｅ－ＦＦＦ－Ｔ１ＷＩ对髌股关节软骨退变的诊断价值。方法：４８个人膝关节行关节镜检查及３Ｄ－Ｖｌｏｕｍｅ－ＦＦＦ－Ｔ１ＷＩ矢状位扫描。矢状位图像行多平面重建（ＭＰＲ）处理。ＭＲ图像每个髋股关节分内、外髌骨面、股骨滑车面与关节镜图像逐一对照分析。结果：关节镜下发现１０２个病变软骨面,３Ｄ－Ｖｏｌｕｍｅ－ＦＦＦ－Ｔ１ＷＩ对软骨病变的分级和关切镜分级间有显著正相关性（Ｐ〈０．０１）。结论：３Ｄ－Ｖｏｌｕｍｅ－ＦＦＦ－Ｔ１ＷＩ结合ＭＰＲ评价髌股关节软骨退弯和关节镜评价关节软骨有很好的相关性、互补性。     

3.0T MRI T2-mapping对膝关节软骨退变的评估价值

目的将MRI表现与病理学对照,研究膝关节胫骨平台软骨退变的MRT2值、T2－mapping表现及其评估关节软骨退变的价值。材料与方法选取全膝关节置换术患者的31个膝关节中符合纳入标准的18个膝关节胫骨平台进行T2－mapping（T2弛豫时间1成像,共扶取98个软骨亚区（标本）,以病理学Mankin分级为标准,评估T2值、T2－mapping伪彩图发现软骨退变的能力。根据组织学Mankin分级标准把不同退变程度的软骨T2值分5组输入数据库,应用单因素方差分析,组问比较采用LSD检验进行统计学处理。结果0级（正常）软骨的T2值[（32．28±4．15）ms]与II级软骨[（34．42±5．76）ms]、l级软骨的T2倩[（37．72±4．83）ms]与II级软骨、III级软。旨的T2值[（41．63±6IO）ms]与IV级软骨[（45．98±7．32）ms]两两比较,差异均尢统计学意义（P值均〉0．05）;I级软骨的T2值与11I缎及IV级、II级软骨的T2值与III级和IV级分别两阳比较,差异均有统计学意义（P值均〈0．05）。总体上,T2值伴随软骨退变程度的增加而明显升高,其中软骨退变II级较I级的T2值轻俊降低,仙II级与I级及正常软骨T2值之间差异尢统计学意义（P值均〉0．05）。T2－mapping伪彩图信号改变可以敏感的发现软骨退变,但尢法K分软骨的退变程度。结论关节软骨的T2值与软骨退,叟程度有着明显的相关性,随着软骨退变程度的加重T2值明显升高,是发现早期软骨退变的敏感方法。     

The effects of bupivacaine and neostigmine on articular cartilage and synovium in the rabbit knee joint

We investigated the effects of intra-articular injections of bupivacaine and neostigmine on articular cartilage and the synovial membrane of rabbit knee joints. Saline, bupivacaine or neostigmine were each administered intra-articularly into 15 knee joints. Five joints per drug treatment were prepared for histopathological examination 24 h, 48 h and 10 days after injection. A pathologist examined the histological samples for inflammation of the articular cartilage, inflammatory cell infiltration, hypertrophy and hyperplasia of the synovial membrane, in a blinded manner. There no histopathological in the saline-treated control joints. Joints treated with bupivacaine and neostigmine showed significantly more histopathological changes than control joints. Joints treated with neostigmine showed significantly more histopathological changes than those treated with bupivacaine, except for articular cartilage inflammation on day 10. We conclude that intra-articular bupivacaine and neostigmine cause histopathological changes in rabbit knee joints, with neostigmine having a greater effect than bupivacaine.     

点种法移植软骨细胞修复关节软骨缺损

背景：生物性的重建虽能达到修复缺损,重建关节面的目的,但功能上难以与正常软骨一致。应用可降解的聚合物把移植的软骨细胞包埋起来进行移植,可能获得真正意义上的透明软骨。目的：观察以同种异体兔软骨细胞胶原包埋后,点种法移植软骨细胞修复关节软骨缺损的效果。方法：新西兰纯种兔制备膝关节全层软骨缺损后分为3组：分别进行胶原包埋软骨细胞点种法移植、单纯软骨细胞点种法移植和仅在大面积软骨缺损的软骨下钻孔。结果与结论：术后2,4,12,24周观察组织学动态变化,发现胶原包埋软骨细胞点种法移植组能获得透明软骨修复,而软骨细胞点种法组和单纯软骨下骨钻孔组缺损区仅为纤维组织填充,并且胶原包埋软骨细胞点种法移植组兔各期平均组织学和组织化学得分均高于其他两组（P〈0.01）。说明胶原包埋点种法软骨细胞移植能获得透明软骨修复,尤其适用于大面积软骨缺损。     

超声对软骨细胞凋亡、caspase-8和caspase-3表达的影响

背景：超声治疗能够缓解疼痛,改善膝骨关节炎患者的运动功能,但目前关于超声治疗的文献缺乏一致性。目的：进一步验证超声治疗的膝骨关节炎有效性。方法：24只兔子随机分为3组,正常组不干预;模型组兔行前交叉韧带离断诱导膝骨关节炎,不接受任何治疗;超声组兔建模后接受超声波治疗10min／次,1次／d,0．3W／cm2,1MHz,共治疗10次。采用苏木精一伊红染色进行兔关节软骨组织学观察,运用免疫印迹和RT-PCR技术检测兔软骨中的caspases3和caspases8的表达,TUNEL技术检测兔膝骨关节软骨细胞凋亡率。结果与结论：正常兔软骨组织软骨细胞呈柱状整齐的排列,模型中软骨层变薄,软骨细胞排列无序而少。超声治疗后软骨细胞重新排列,趋于整齐,细胞数增加。模型组为膝骨关节炎模型;与正常组比较,模型组和超声组改良Mankin评分较高,模型组和超声组软骨细胞凋亡指数更高,模型组高于超声组。与正常组比较,模型组和超声组caspase．3和caspase．8表达较高,超声治疗后两项指标表达下降。结果表明,超声可以改善软骨组织结构、降低caspase．3、caspase．8的表达,降低软骨细胞凋亡。提示超声治疗膝骨关节炎是有效的。     

Recombinant adeno-associated virus vectors efficiently and persistently transduce chondrocytes in normal and osteoarthritic human articular cartilage

Successful gene transfer into articular cartilage is a prerequisite for gene therapy of articular joint disorders. In the present study we tested the hypothesis that recombinant adeno-associated virus (rAAV) vectors are capable of effecting gene transfer in isolated articular chondrocytes in vitro, articular cartilage tissue in vitro, and sites of articular damage in vivo. Using an rAAV vector carrying the Escherichia coli beta-galactosidase gene (lacZ) under the control of the cytomegalovirus (CMV) immediate-early promoter/enhancer (rAAV-lacZ), transduction efficiency exceeded 70% for isolated normal human adult articular chondrocytes, and osteoarthritic human articular chondrocytes. These were comparable to the transduction efficiency obtained with neonatal bovine articular chondrocytes. Transduction of explant cultures of articular cartilage resulted in reporter gene expression within the tissue of all three cartilage types to a depth exceeding 450 microm, which remained present until 150 days. When rAAV-lacZ vectors were applied to femoral chondral defects and osteochondral defects in vivo in a rat knee model, reporter gene expression was achieved for at least 10 days after transduction. These data suggest that AAV-based vectors can efficiently transduce and stably express foreign genes in articular chondrocytes, including chondrocytes of normal and osteoarthritic human articular cartilage. The data further suggest that the same rAAV vectors are capable of transducing chondrocytes in situ within their native matrix to a depth sufficient to be of potential clinical significance. Finally, the data demonstrate that these rAAV vectors are capable of effectively delivering recombinant genes to chondral and osteochondral defects in vivo.