自体骨髓基质干细胞及可注射藻酸钙凝胶联合Mosaicplasty技术修复山羊膝关节股骨头大面积缺损

背景：目前修复软骨缺损的方法都存在修复组织数量不足，生物力学性能不佳，整合不良及供区并发症等缺陷。对于大面积的骨软骨复合缺损单独应用一种方法尚显不足。目的：观察组织工程方法复合Mosaicplasty技术用于修复大面积骨软骨缺损的效果。设计、时间及地点：随机对照动物实验，于2009—0I／09在青岛大学医学院中心实验室完成。材料：体外培养并扩增健康成年雄性山羊的骨髓基质干细胞，收集约3×10^7细胞，加入1mL藻酸钠溶液重恩形成骨髓丛质干细胞-藻酸钙凝胶材料。方法：12只山羊用于制备膝关节股骨髁大面积骨软骨缺损模型，骨髓基质干细胞Mosaicplasty组使用自制Mosaicplasty器械，植入直径2mm骨软骨柱镶嵌充填缺损，以自体骨髓基质干细胞复合藻酸钙凝胶填充残余缺损和部分供区。Mosaicplasty组单纯用Mosaicplasty修复骨软骨缺损。对照组单纯制造缺损不修复。主要观察指标：①大体观察：术后4，8，16周分别切开关节观察修复效果。②组织学检查：术后16周取修复组织标本，行苏木精-伊红染色、甲苯胺蓝染色光镜下观察。③电镜观察：取16局修复组织行透射电镜检查。结果：术后16周时骨髓基质干细胞-Mosaicplasty组移植物固定牢固，关节面平滑，移植物间界限消失，新生软骨组织类似于正常软骨，4-16周修复效果逐渐改善，优于其他各组。光镜观察细胞-凝胶新生软骨组织与移植软骨结合紧密，新生软骨细胞排列规整，细胞外基质分布均。对照组无明显修复。透剔电镜观察发现修复新生组织中细胞形态类似软骨细胞，细胞存在于排列紧密的纤维网格中，基质丰富。结论：使用自体骨髓基质干细胞-藻酸钙凝胶材料复合Mosaicplasty技术可促进骨软骨整合．改善其修复效果。

Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

The aim of this study was to evaluate the efficacy of mosaicplasty with tissue-engineered cartilage for the treatment of osteochondral defects in a pig model with advanced MR technique. Eight adolescent miniature pigs were used. The right knee underwent mosaicplasty with tissue-engineered cartilage for treatment of focal osteochondral defects, while the left knee was repaired via single mosaicplasty as controls. At 6, 12, 18 and 26 weeks after surgery, repair tissue was evaluated by magnetic resonance imaging （MRI） with the cartilage repair tissue （MOCART） scoring system and T2 mapping. Then, the results of MRI for 26 weeks were compared with findings of macroscopic and histologic studies. The MOCART scores showed that the repaired tissue of the tissue-engineered cartilage group was statistically better than that of controls （P 〈 0.001）. A significant correlation was found between macroscopic and MOCART scores （P 〈 0.001）. Comparable mean T2 values were found between adjacent cartilage and repair tissue in the experimental group （P 〉 0.05）. For zonal T2 value evaluation, there were no significant zonal T2 differences for repair tissue in controls （P 〉 0.05）. For the experimental group, zonal T2 variation was found in repair tissue （P 〈 0.05）. MRI, macroscopy and histology showed better repair results and bony incorporation in mosaicplasty with the tissue-engi- neered cartilage group than those of the single mosaicplasty group. Mosaicplasty with the tissue-engineered cartilage is a promising approach to repair osteochodndral defects. Morphological MRI and T2 mapping provide a non-invasive method for monitoring the maturation and integration of cartilage repair tissue in vivo.

Seamless and early gap healing of osteochondral defects by autologous mosaicplasty combined with bioactive supramolecular nanofiber-enabled gelatin methacryloyl(BSN-GelMA)hydrogel

Autologous mosaicplasty is a common approach used to treat osteochondral defects in clinical practice.Gap integration between host and transplanted plugs requires bone tissue reservation and hyaline cartilage regeneration without uneven surface,graft necrosis and sclerosis.However,poor gap integration is a serious concern,which eventually leads to deterioration of joint function.To deal with such complications,this study has developed a strategy to effectively enhance integration of the gap region following mosaicplasty by applying injectable bioactive supramolecular nanofiber-enabled gelatin methacryloyl(GelMA)hydrogel(BSN-GelMA).A rabbit osteochondral defect model demonstrated that BSN-GelMA achieved seamless osteochondral healing in the gap region between plugs of osteochondral defects following mosaicplasty,as early as six weeks.Moreover,the International Cartilage Repair Society score,histology score,glycosaminoglycan content,subchondral bone volume,and collagen II expression were observed to be the highest in the gap region of BSN-GelMA treated group.This improved outcome was due to bio-interactive materials,which acted as tissue fillers to bridge the gap,prevent cartilage degeneration,and promote graft survival and migration of bone marrow mesenchymal stem cells by releasing bioactive supramolecular nanofibers from the GelMA hydrogel.This study provides a powerful and applicable approach to improve gap integration after autologous mosaicplasty.It is also a promising off-the-shelf bioactive material for cell-free in situ tissue regeneration.

Cartilage repair techniques of the talus: An update

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients.Although their pathomechanism is well understood,it is well known that different aetiologic factors play a role in their origin.Additionally,it is well recognised that the talar articular cartilage strongly differs from that in the knee.Despite this fact,many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee.Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans.However,depending on the size of the lesions,surgical approaches are necessary to treat many of these defects.Bone marrow stimulation techniques may achieve good results in small lesions.Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation.Autologous chondrocyte transplantation,as a restorative procedure,is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor.The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.