同种异体肋软骨膜移植半月板再生的实验研究

目的：探究同种异体肋软骨膜游离移植再生半月板的能力及其预防关节退变的意义。材料及方法：选用成年家犬10只，双膝关节内侧半月板切除后随机选取一侧膝关节内侧间隙植入同种异体肋软骨膜（同种异体移植组），对侧膝关节植入自体肋软骨膜（自体移植组），以全部切除的正常半月板及正常膝关节作为对照（对照组）。分别于术后4、8、12周切取标本，进行大体、光镜（HE染色及Alcian-blue,Safranin 0复杂）、透射电镜观察，并对正常半月板及术后12周的移植物进行生物力学测试。结果：12周时所有移植物都衍化再生出接近正常半月板大小及形态的纤维软骨板。在整个实验过程中未见明显的免疫排斥反应。生物力学测试结果显示两移植组再生半月板的抗拉伸性能无显著性差异，均低于正常半月板。结论：同种异体肋软骨膜游离移植于半月板缺失的犬的膝关节中可以存活，并可再生出接近正常形态、结构的半月板，无免疫排斥反应。     

自体游离骨膜再造膝关节半月板的实验研究

目的：对于严重损伤的半月板全切除术后行自体游离骨膜重建半月板，以维持膝关节结构、生理及功能特性。方法：使用１７只成年犬，５只幼犬。外侧半月板全切除以后，胫骨内侧近端的骨膜游离并移植到外侧半月板部位。于２、４、８、１２、２４、４８周取下重建半月板及不同部位的关节面软骨进行大体、光镜及电镜观察。结果：术后２个月，重建半月板的大体形态、组织结构与正常半月板近似。外侧股骨软骨面及没有被覆盖的胫骨软骨面表现退行性改变，被移植物覆盖的软骨面退变较轻。幼犬的退变更早、更严重。结论：本研究说明了自体游离骨膜在滑液环境及受到合适的应力刺激会向纤维软骨演化，在半月板全切除后，应用游离骨膜重建半月板是可行的     

异体半月板移植的研究进展

膝关节半月板具有重要的生物力学功能，它可增加关节软骨之间的接触面积，降低关节软骨单位面积上的负荷；它的楔形截面可稳定膝关节，其弹性组织结构可吸收振荡；此外，半月板对关节软骨还具有润滑作用。半月板切除后，将丧失上述功能，导致或加速膝关节的退行性变。因此，近１０年来开始采用异体半月板移植技术重建受损半月板，缓解临床症状和阻止因半月板丧失导致的膝关节退行性变的发展。一、异体半月板移植的动物实验Arnoczky等犤１犦报告１４例成年犬低温保存的异体内侧半月板移植，观察２周～６个月，移植半月板的外形保持正常，与…     

改善异体半月板移植预后的相关因素研究

异体半月板移植的目的是恢复半月板缺失膝关节的正常生物力学环境,保护关节软骨,延缓膝关节退变性关节炎的发生。异体半月板的构成、大小匹配程度、移植物再血管化的速度以及是否应用相关的生长因子等,影响移植预后。     

采用异体腘绳肌腱Rigidfix交叉钉与Intrafix膨胀挤压螺钉重建前交叉韧带初步报道

前交叉韧带(anterior cruciate ligament,ACL)损伤是常见的膝关节韧带损伤,如不及时修复将造成膝关节其他韧带松弛、关节软骨退变、半月板损伤等并发症,严重影响膝关节功能。关节镜下ACL重建术作为修复ACL、延缓膝关节退变的重要方法[1],已被广泛应用于临床,其移植物和移植材料     

半月板移植供体选择

半月板由纤维软骨组成，是膝关节的重要组成部分，具有吸收震荡、传递负荷、营养关节软骨、润滑和增加关节接触面积以及维持关节稳定等重要功能。半月板的外缘肥厚，内缘锐薄，周边部分的血液供应尚充分，其余部分血供差，缺乏修复再生能力。随访调查发现，半月板切除部分的大小与膝关节骨性关节炎的发病风险密切相关。半月板严重损伤或切除后，半月板对关节软骨的保护作用丧失、关节软骨退变加速、导致膝关节不稳和骨性关节炎的发生。远期随访后会较早出现关节软骨退变现象。随着对半月板结构和功能认识的深入，半月板不可缺失的观点已得到公认。过去一直以半月板全切除术作为治疗的主要手段，而现在随着对半月板功能及半月板切除后并发症认识的不断深入，则尽可能修复和保留半月板的功能。对于无法保留半月板的患者，半月板的移植或再造修复成为人们最为关注的问题。目前再造修复重度损伤半月板的结构和功能已成为国内外学者研究的重点。     

应用犬真皮成纤维细胞构建组织工程半月板修复犬半月板缺损的实验研究

目的 探讨体外构建组织工程半月板修复半月板缺损的可行性.方法 将体外扩增至第4代的犬真皮成纤维细胞(Dermal fibroblasts,DFs)接种于PGA/PLA支架材料上,应用软骨形态发生蛋白1(Cartilage-derived morphogenetic protein-1,CDMP1)细胞诱导液体外诱导培养2周后,回植于犬自体半月板缺损模型体内,移植后6个月取材观察半月板的再生情况.结果 诱导组模型内形成较大的新生半月板组织,组织学染色显示诱导组新生组织更接近于半月板组织的生理特点,尤其是内侧部分大部分细胞表现出软骨细胞特有的陷窝结构;非诱导组及空白对照组新生的组织较小,且组织学表现更类似纤维结缔组织.新生半月板Ⅰ型胶原偏振光检测显示,诱导组胶原纤维排列较非诱导组致密,出现Ⅰ型胶原的横纹特征.扫描电镜检测显示,诱导组细胞外基质与正常半月板相比较疏松,非诱导组细胞外基质则更加疏松.膝关节胫骨平台关节软骨的HE染色显示,诱导组关节面的外侧有新生半月板组织覆盖的部位关节软骨尚有部分存余,而诱导组已基本消失.结论 组织工程化细胞材料复合物能在犬自体半月板缺损模型上实现半月板再生.     

轻度OA膝关节有限元解剖模型的构建及其力学分析

[目的]构建轻度OA膝关节的有限元解剖模型,并用于研究在OA膝关节关节软骨和半月板上的应力分布特征。[方法]基于MRI和CT影像数据构建具有骨性结构和非骨性结构的轻度OA膝关节有限元解剖模型,定义材料属性并确定边界条件和轴向载荷,以胫股关节间软骨接触的Mises应力和接触压强为研究指标,分析关节内的应力分布特征。[结果]构建了轻度OA膝关节三维有限元解剖模型,有限元分析结果表明内侧胫骨近端关节软骨接触压强大于外侧室,外侧半月板接触压强峰值大于内侧室;股骨远端与胫骨近端关节软骨边缘处Mises应力峰值大于胫股关节间软骨接触部分,外侧半月板最大Mises应力位于半月板中部,而内侧半月板最大Mises应力位于半月板后部。[结论] OA膝关节内应力分布特征不同于正常膝关节,内侧半月板半脱位和关节软骨退变的特征促进了膝OA的进一步发展。     

同种异体半月板联合骨软骨移植的实验研究

目的:探讨新鲜同种异体半月板骨软骨联合移植治疗胫骨平台毁损伤后骨关节炎的疗效。方法:成年新西兰大白兔36只,随机分为A、B、C3组,各12只。A组行右膝内侧半月板连同胫骨平台骨软骨移植,克氏针交叉固定骨块。B组行右膝内侧半月板移植,左膝内侧半月板取出制备新鲜冷冻半月板。C组行左膝内侧新鲜冷冻半月板移植。术后4、8、12周分批取材行大体观察、组织学检查和胫骨平台软骨氨基己糖(GAG)测定。结果:12周时A组移植胫骨平台软骨与B、C组半月板移植术后的内侧胫骨平台软骨氨基己糖含量差异无统计学意义;A、B组移植的半月板纤维软骨细胞数差异无统计学意义;A组半月板移植的纤维软骨细胞数多于C组。结论:新鲜同种异体半月板骨软骨联合移植能修复胫骨平台毁损伤。     

一种双相半月板支架修复兔内侧半月板缺失的实验研究

目的研究脱钙骨基质/脱细胞半月板基质双相支架对兔内侧半月板缺失的修复作用的影响。方法取健康成年新西兰大白兔24只,建立兔膝关节左膝内侧半月板缺损模型,随机分为两组。A组:空白对照组,兔左膝内侧半月板切除术后旷置;B组:双相支架植入组,兔左膝内侧半月板切除术后,脱钙骨基质/脱细胞半月板基质双相支架原位植入。分别于内侧半月板切除术后3、6个月处死兔并取材对比,行HE染色、甲苯胺蓝染色、番红O染色以及天狼星红染色,并对各组半月板修复情况及其软骨保护情况进行形态学及组织学观察。结果本研究中的兔在手术后3、6个月处死后,观察其膝关节半月板及其对应股骨髁和胫骨平台软骨形态学和组织学,结果显示双相支架植入组要明显好于对照组,HE、甲苯胺蓝、番红O、天狼星红染色可见实验组新生半月板已经接近正常半月板。结论脱钙骨基质/脱细胞半月板基质双相支架对兔内侧半月板缺失后半月板的修复以及关节软骨的保护具有良好的作用,可以很好的促进半月板的再生,是一种良好的组织工程半月板的支架。     

Meniscal replacement using a cryopreserved allograft. An experimental study in the dog

The medial menisci of 14 adult dogs were replaced using a cryopreserved meniscal allograft. The morphology and metabolic activity of the transplanted allografts were then evaluated using routine histology, a vascular-injection (Spalteholz) technique, and autoroentgenography (Na2(35)SO4 incorporation) at various intervals, from two weeks to six months postoperatively. After transplantation, the allografts retained their normal gross appearance and healed to the capsular tissues of the host by fibrovascular scar tissue. Histologically, the grafts demonstrated a decrease in the number of metabolically active cells after transplantation but had a normal cellular distribution and Na2(35)SO4 uptake by three months. The allografts appeared to function normally after transplantation. Although some degenerative changes were noted in the tibial articular cartilage not covered by the meniscus, the cartilage beneath the allograft appeared normal.     

Porcine small intestine submucosa for repair of goat meniscal defects

This study evaluated the effectiveness of small intestine submucosa used as a graft to fill surgically created meniscal defects in a large animal model. Four goats underwent unilateral interior subtotal meniscectomies (approximately 70%) within the avascular portion of the medial meniscus. The contralateral meniscus acted as a control. Grafts of porcine small intestine submucosa were trimmed to fill the resected defects and sutured into place. After surgery the operated knees were casted in partial flexion to limit weight bearing on the affected limb. All of the animals were sacrificed at 12 weeks at which point meniscal regeneration and articular cartilage degradation were evaluated by gross and histologic examination. Grossly, the defects in the small intestine submucosa-grafted goats were partially filled with meniscal-appearing connective tissue. Histologically, the replacement tissue was typified by the presence of dense, cellular, irregularly organized connective tissue. Evaluation of the articular cartilage displayed increased degeneration in the grafted compartment of the operative knees. Each of the operative menisci partially regenerated. The grafts were conducive to repopulation with host meniscal elements. Despite partial meniscal regeneration, comparatively more articular cartilage degeneration in the treated knees was observed than in the untreated contralateral controls.     

Treatment of articular defects with meniscal allografts in a rabbit knee model

Deep-frozen allogeneic meniscal grafts for the treatment of articular cartilage defects were performed experimentally. Osteochondral defects 3 mm in diameter were created bilaterally on the medial femoral condyles of 50 Japanese white rabbits. A meniscus was then grafted into the defect in the left knee, and the right knee was left untreated. At various periods from 2 to 24 weeks postoperatively, the rabbits were killed and macroscopic and histologic examinations were performed. Two weeks after operation, the grafted meniscus was bonded to the floor of the defect. After 12 weeks, chondrocytes producing matrix granules was shown by electron microscopy. After 24 weeks, a congruous articular surface was formed. With time, cellular elements infiltrated into the graft from the surrounding tissues, and gradually increased in penetration. Weight bearing in the early stage after operation did not degrade the grafted menisci, and no changes were shown in the opposing cartilage of the tibia. Deep-frozen allogeneic menisci may be useful as a biological implant to repair articular cartilage defects in this model.     

Assessment of donor cell and matrix survival in fresh articular cartilage allografts in a goat model

The long-term survival of allografts of articular cartilage has been proposed to be dependent on the survival of the cells that maintain the unique structural and material properties of the allograft. In this study, we assessed cell survival in 24 fresh articular cartilage allografts of the medial plateau in a Spanish-goat model. A DNA-probe technique was used to distinguish clearly between DNA from donor (allograft) and host cells. The intraarticular survival of viable allograft chondrocytes in the transplanted articular cartilage started to diminish as early as 3 weeks after transplantation; however, there was considerable variation in the amount of donor cell DNA detected in the allografts at 6 and 12 months following transplantation. This contrasts with our experience with fresh allografts of ligament, tendon, and meniscus, in which no donor DNA was detected 4 weeks after transplantation. DNA from host cells was present in all articular cartilage allografts, as evidenced by detectable unique host DNA patterns. Histological and histochemical assays showed that none of the transplants demonstrated normal structure and composition at 1 year after transplantation. The grafts in which large quantities of donor DNA were present appeared grossly superior to those with no or reduced remaining demonstrable donor DNA.     

Transplantation of autologous synovial mesenchymal stem cells promotes meniscus regeneration in aged primates

Transplantation of aggregates of synovial mesenchymal stem cells (MSCs) enhanced meniscus regeneration in rats. Anatomy and biological properties of the meniscus depend on animal species. To apply this technique clinically, it is valuable to investigate the use of animals genetically close to humans. We investigated whether transplantation of aggregates of autologous synovial MSCs promoted meniscal regeneration in aged primates. Chynomolgus primates between 12 and 13 years old were used. After the anterior halves of the medial menisci in both knees were removed, an average of 14 aggregates consisting of 250,000 synovial MSCs were transplanted onto the meniscus defect. No aggregates were transplanted to the opposite knee for the control. Meniscus and articular cartilage were analyzed macroscopically, histologically, and by MRI T1rho mapping at 8 (n = 3) and 16 weeks (n = 4). The medial meniscus was larger and the modified Pauli's histological score for the regenerated meniscus was better in the MSC group than in the control group in each primate at 8 and 16 weeks. Mankin's score for the medial femoral condyle cartilage was better in the MSC group than in the control group in all primates at 16 weeks. T1rho value for both the regenerated meniscus and adjacent articular cartilage in the MSC group was closer to the normal meniscus than in the control group in all primates at 16 weeks. Transplantation of aggregates of autologous synovial MSCs promoted meniscus regeneration and delayed progression of degeneration of articular cartilage in aged primates. This is the first report dealing with meniscus regeneration in primates. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1274–1282, 2017.

     

The long-term effects of hyaluronan during development of osteoarthritis following partial meniscectomy in a rabbit model

OBJECTIVE: The long-term effect of hyaluronan (HA) on meniscus remodeling and articular cartilage preservation was assessed during the development of osteoarthritis following partial meniscectomy in a rabbit model. DESIGN: Approximately 60% of the region of each medial meniscus of 20 rabbit knees was excised bilaterally. The left knee joint was treated with five weekly intraarticular injections of 0.3 ml of HA, beginning 1 week after surgery. The right control knee was injected with PBS on the same schedule. Six months after surgery, animals were killed and the medial menisci and tibial articular cartilage were evaluated morphologically, histologically and biochemically. RESULTS: Meniscal regeneration was observed as newly synthesized translucent tissue, and image analysis revealed that the amount of this tissue was significantly greater in the HA-treated menisci than in the vehicle-treated menisci. Safranin-O staining and image analysis revealed the increased presence of glycosaminoglycans in the HA-treated menisci relative to vehicle-treated menisci while vascularity and biochemical parameters (hydration, total GAGs and reducible collagen crosslinks) were statistically similar in HA- and vehicle-treated menisci. Gross morphologic grading with India ink revealed a trend for less deterioration of tibial articular cartilage in the HA group (P=0.09) while Mankin's score of the HA-treated tibial articular cartilage was marginally lower than that of the vehicle group (P=0.06). Biochemical assessments showed a trend for higher total GAGs concentration in the HA-treated articular cartilage when compared to the vehicle treatment group (P=0.06). CONCLUSION: The present study has demonstrated that following partial meniscectomy, treatment with hyaluronan can enhance meniscal regeneration and may inhibit articular cartilage degeneration as long as six months post surgery.     

Reconstruction of patellar cartilage defects with free periosteal grafts. An experimental study

The osteo-chondrogenic potential of free periosteal grafts was investigated within the knee joint in 26 rabbits aged four to six weeks. A total of 36 knee joints were operated on. The grafts were stripped from the medial side of the right tibia and sutured on the articular surface of the patella, from which the cartilage had been totally excised to the subchondral bone. In 16 knees the graft was sutured with the cambium layer towards the subchondral bone and in eight knees the fibrous layer faced the bone. In the control group of twelve knees the patellar articular cartilages were excised and no periosteal transplant was grafted to the patellar articular surface. In the transplantation group cartilage formation could be seen already one week after the operation. There were no marked differences between the series with the cambium layer facing the subchondral bone or the group with the fibrous layer facing the bone. At 20 weeks the hypertrophied cartilage had thinned and resembled normal joint cartilage. In the control group the histological picture resembled osteoarthritis.     

The degenerative effects of partial and total resection of the medial meniscus in dogs' knees.

An experimental effort to determine the degenerative effects in the articular cartilage of the knee joint caused by meniscectomy was performed by doing partial and total meniscectomies on the medial compartment of dogs' knees. Gross and microscopic pathological changes in teh articular cartilage were studied by sacrificing the dogs at intervals of three to ten months. Results indicated that meniscectomy is not a benign procedure, and the removal of a meniscus in itself can lead to degenerative changes in the knee joint. Partial meniscectomy leads to less severe degenerative changes with the degree of change directly related to the amount of meniscus removed. In total meniscectomies when meniscus regeneration occurred, the cartilage surfaces where the meniscus had regenerated were protected. The degree of degenerative change was directly related to the amount of fibrocartilage that remained absent. Therefore, the knee menisci function to protect the articular cartilages from degenerative damages, but the exact mechanism of this is unknown.     

Allotransplantation of meniscus in dog's knee. An experimental study]

This experimental study was to show the difference and outcome of allotransplantation and autotransplantation of meniscus in dogs. In the experimental group (9 dogs), the lateral meniscus was removed and replaced by one preserved for 2 weeks in tissue culture. In the control group (9 dogs), the lateral meniscus was excised but was sutured back to the place immediately. The specimens in each group were taken at 3, 6, 12, and 24 weeks after operation, and were examined microangiographically and histologically under light microscope and electron microscope. The results in both groups showed that the meniscus united to the capsule, chondrocytes in the menisci were intact and the collagen fiber orientation was regular. The articular cartilage of the uncovered area of the tibial plateaus showed normal appearance, and vascular neogenesis in the meniscal periphery was found 12 weeks after operation. These observations suggest that allogenic meniscus maintains its original histologic pattern and functional behavior after its transplantation. It makes possible to protect the knee joint from osteoarthritis.