The osteochondral dilemma: review of current management and future trends

The management of articular cartilage defects remains challenging and controversial. Hyaline cartilage has limited capacity for self‐repair and post‐injury cartilage is predominantly replaced by fibrocartilage through healing from the subchondral bone. Fibrocartilage lacks the key properties that characterize hyaline cartilage such as capacity for compression, hydrodynamic permeability and smoothness of the articular surface. Many reports relate compromised function associated with repaired cartilage and loss of function of the articular surface. Novel methods have been proposed with the key aim to regenerate hyaline cartilage for repair of osteochondral defects. Over the past decade, with many exciting developments in tissue engineering and regenerative cell‐based technologies, we are now able to consider new combinatorial approaches to overcome the problems associated with osteochondral injuries and damage. In this review, the currently accepted surgical approaches are reviewed and considered; debridement, marrow stimulation, whole tissue transplantation and cellular repair. More recent products, which employ tissue engineering approaches to enhance the traditional methods of repair, are discussed. Future trends must not only focus on recreating the composition of articular cartilage, but more importantly recapitulate the nano‐structure of articular cartilage to improve the functional strength and integration of repair tissue.     

Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC)

Degenerative and traumatic articular cartilage defects are common, difficult to treat, and progressive lesions that cause significant morbidity in the general population. There have been multiple approaches to treat such lesions, including arthroscopic debridement, microfracture, multiple drilling, osteochondral transplantation and autologous chondrocyte implantation (ACI) that are currently being used in clinical practice. Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC) is a single-staged arthroscopic procedure. This method combines a modified microfracture technique with the application of a bone marrow aspirate concentrate (BMAC), hyaluronic acid and fibrin gel to treat articular cartilage defects. We reviewed the current literatures and surgical techniques for mesenchymal cell induced chondrogenesis.     

Arthroskopische M?glichkeiten biorekonstruktiver Verfahren bei Knorpelsch?den der Schulter

Chondral or osteochondral lesions of the shoulder may lead to premature osteoarthritis of the glenohumeral joint as regeneration of damaged articular cartilage is lacking. Rising health awareness, increasingly active populations and improvements in medical techniques have increased the application of cartilage regenerative minimally invasive approaches for glenohumeral joint preservation or delayed prosthetic replacement. In contrast to the conclusive and mostly convincing mid-term results of cartilage regenerative techniques known for the knee, clinical results of innovative therapeutic approaches with glenohumeral cartilage defects are more or less absent. Current techniques include procedures for mesenchymal stem cell recruitment, such as microfracturing, (autologous) osteochondral transplantation, (matrix-associated) autologous chondrocyte transplantation and biological resurfacing, addressing focal chondral defects up to massive structural osteochondral defects. With increasing arthroscopic applicability, they evolve to important tools in the armamentarium of the shoulder surgeon. Future clinical data will determine evidence-based applicability, enabling standardized treatment selection.     

Orderly osteochondral regeneration in a sheep model using a novel nano‐composite multilayered biomaterial

The objective of this article was to investigate the safety and regenerative potential of a newly developed biomimetic scaffold when applied to osteochondral defects in an animal model. A new multilayer gradient nano‐composite scaffold was obtained by nucleating collagen fibrils with hydroxyapatite nanoparticles. In the femoral condyles of 12 sheep, 24 osteochondral lesions were created. Animals were randomized into three treatment groups: scaffold alone, scaffold colonized in vitro with autologous chondrocytes and empty defects. Six months after surgery, the animals were sacrificed and the lesions were histologically evaluated. Histologic and gross evaluation of specimens showed good integration of the chondral surface in all groups except for the control group. Significantly better bone regeneration was observed both in the group receiving the scaffold alone and in the group with scaffold loaded with autologous chondrocytes. No difference in cartilage surface reconstruction and osteochondral defect filling was noted between cell‐seeded and cell‐free groups. In the control group, no bone or cartilage defect healing occurred, and the defects were filled with fibrous tissue. Quantitative macroscopic and histological score evaluations confirmed the qualitative trends observed. The results of the present study showed that this novel osteochondral scaffold is safe and easy to use, and may represent a suitable matrix to direct and coordinate the process of bone and hyaline‐like cartilage regeneration. The comparable regeneration process observed with or without autologous chondrocytes suggests that the main mode of action of the scaffold is based on the recruitment of local cells. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:116–124, 2010     

脱细胞骨软骨支架复合自体骨髓间充质干细胞修复羊骨软骨缺损的研究

目的探讨脱细胞骨软骨支架接种自体骨髓间充质干细胞(BMSCs)修复羊骨软骨缺损效果,探索骨软骨缺损新的修复方式。方法制备直径为8mm骨软骨脱细胞支架,培养羊BMSCs,接种于骨软骨支架,制备羊负重区骨软骨缺损模型,分空白、空白支架及细胞支架复合物3组,每组4只羊,3个月后处死动物取标本行大体及组织学检测。结果修复羊负重区骨软骨缺损模型实验结果显示细胞支架复合修复组骨软骨有较好修复,空白支架组软骨下骨基本修复、软骨侧无明显修复,空白对照组未见明显修复,缺损边缘软骨退变。结论含骨软骨连接结构的脱细胞骨软骨支架接种种子细胞能较好的修复羊负重区骨软骨缺损。     

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model

Background

Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects.

Co-Culture of Adipose Derived Stem Cells and Chondrocytes with Surface Modifying Proteins Induces Enhanced Cartilage Tissue Formation

ABSTRACT

Objectives: Current treatments for focal cartilage defects include osteochondral allograft transplants—a common treatment for large defects and revisions of previously autografted joints. Allografts with weak osseous regions are usable, since bone remodeling replaces inferior quality bone. However, poor quality chondral surfaces on grafts preclude their use, leading to grafting material shortages. Endogenous adult stem cells can make hyaline-like cartilage tissue on scaffolds. To increase the number of usable allografts, tissue culture methods using adipose derived stem cells (ASCs) were developed to grow cartilage on grafts. Methods: Co-cultures utilized living chondrocytes in host cartilage, modeling in vivo conditions, and ASCs seeded on the allografts. Sterilized allografts were treated with Poly-L-Lysine and ProNectin. Tissue growth was analyzed and quantified with histological techniques. Results and Conclusions: Monoculture experiments produced tenuous cartilage formation when proteins were utilized and allograft surfaces were perforated. Extensive tissue formation was observed with co-culture and the presence of type II collagen was confirmed with immunohistochemistry. Results demonstrate that co-culture techniques offer a better means of growing tissue on allograft cartilage surfaces. Additionally, the use of proteins to facilitate surface attachment produced more tissue formation demonstrating that cell attachment is crucial when growing cartilage on allografts. Development of new culture techniques to evaluate treatment strategies will accelerate the rate at which cartilage procedures using endogenous cells are possible. This will increase the number of usable grafts and allow critical selection of grafts to fit specific surfaces increasing surgical success by returning the joint to its native structure.     

Failure of xenoimplantation using porcine synovium‐derived stem cell‐based cartilage tissue constructs for the repair of rabbit osteochondral defects

The use of xenogeneic tissues offers many advantages with respect to availability, quality control, and timing of tissue harvest. Our previous study indicated that implantation of premature tissue constructs from allogeneic synovium‐derived stem cells (SDSCs) facilitated cartilage tissue regeneration. The present study investigated the feasibility of xenoimplantation of SDSC‐based premature tissue constructs for the repair of osteochondral defects. Porcine SDSCs were mixed with fibrin gel, seeded in polyglycolic acid (PGA) scaffolds, and cultured in a rotating bioreactor system supplemented for 1 month with growth factor cocktails. The engineered porcine premature tissues were implanted to repair surgically induced osteochondral defects in the medial femoral condyles of 12 rabbits. Three weeks after surgery, the xenoimplantation group exhibited a smooth, whitish surface while the untreated control remained empty. Surprisingly, 6 months after surgery, the xenoimplantation group displayed some tissue loss while the untreated control group was overgrown with fibrocartilage tissue. In the xenoimplantation group, chronic inflammation was observed in synovial tissue where porcine major histocompatibility complex (MHC) class II antigen positively stained in the engulfed foreign bodies. In addition, porcine source cells also migrated from the implantation site and may have been responsible for the observed loss of glycosaminoglycans (GAGs) underneath surrounding articular cartilage. The histological score was much worse in the xenoimplanted group than in the untreated control. Our study suggested that SDSC‐based xenogeneic tissue constructs might cause delayed immune rejection. Xenotransplantation may not be an appropriate approach to repair osteochondral defects. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1064–1070, 2010     

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.     

Repair of large osteochondral defects with allogeneic cartilaginous aggregates formed from bone marrow-derived cells using RWV bioreactor.

Our objective was to examine the technique of regenerating cartilage tissue from bone marrow-derived cells by three-dimensional (3D) culture using the rotating wall vessel (RWV) bioreactor. Three-dimensional and cylindrical aggregates of allogeneic cartilage with dimensions of 10 x 5 mm (height x diameter) formed by the RWV bioreactor were transplanted into osteochondral defects of Japanese white rabbits (Group T, n = 15). For the control, some osteochondral defects were left empty (Group C, n = 18). At 4, 8, and 12 weeks postimplantation, the reparative tissues were evaluated macroscopically, histologically, and biochemically. In Group T at as early as 4 weeks, histological observation, especially via safranin-O staining, suggested that the reparative tissues resembled hyaline cartilage. And we observed no fibrous tissues between reparative tissue and adjacent normal tissues. In the deeper portion of the bony compartment, the osseous tissues were well remodeled. At 4 and 8 weeks postimplantation, the mean histological score of Group T was significantly better than that of Group C (p < 0.05). The glycosaminoglycans (GAG)/DNA ratio in both groups increased gradually from 4 to 8 weeks and then decreased from 8 to 12 weeks. We herein report the first successful regeneration of cartilage in osteochondral defects in vivo using allogeneic cartilaginous aggregates derived from bone marrow-derived cells by 3D culture using the RWV bioreactor.     

A novel MSC‐seeded triphasic construct for the repair of osteochondral defects

Mesenchymal stem cells (MSC) are increasingly replacing chondrocytes in tissue engineering based research for treatment of osteochondral defects. The aim of this work was to determine whether repair of critical‐size chronic osteochondral defects in an ovine model using MSC‐seeded triphasic constructs would show results comparable to osteochondral autografting (OATS). Triphasic implants were engineered using a beta‐tricalcium phosphate osseous phase, an intermediate activated plasma phase, and a collagen I hydrogel chondral phase. Autologous MSCs were used to seed the implants, with chondrogenic predifferentiation of the cells used in the cartilage phase. Osteochondral defects of 4.0 mm diameter were created bilaterally in ovine knees (n = 10). Six weeks later, half of the lesions were treated with OATS and half with triphasic constructs. The knees were dissected at 6 or 12 months. With the chosen study design we were not able to demonstrate significant differences between the histological scores of both groups. Subcategory analysis of O'Driscoll scores showed superior cartilage bonding in the 6‐month triphasic group compared to the autograft group. The 12‐month autograft group showed superior cartilage matrix morphology compared to the 12‐month triphasic group. Macroscopic and biomechanical analysis showed no significant differences at 12 months. Autologous MSC‐seeded triphasic implants showed comparable repair quality to osteochondral autografts in terms of histology and biomechanical testing. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1586–1599, 2010     

Osteochondral regeneration using constructs of mesenchymal stem cells made by bio three‐dimensional printing in mini‐pigs

Osteoarthritis is a major joint disease that has been extensively investigated in humans and in model animals. In this study, we examined the regeneration of articular cartilage and subchondral bone using artificial scaffold‐free constructs composed of adipose tissue‐derived mesenchymal stem cells (AT‐MSCs) created using bio three‐dimensional (3D) printing with a needle‐array. Printed constructs were implanted into osteochondral defects created in the right femoral trochlear groove of six mini‐pigs, using femoral defects created in the left femurs as controls. Repair within the defects was evaluated at 3 and 6 months post‐implantation using computed tomography (CT) and magnetic resonance (MR) imaging. The radiolucent volume (RV, mm³) in the defects was calculated using multi‐planar reconstruction of CT images. MR images were evaluated based on a modified 2D‐ MOCART (magnetic resonance observation of cartilage repair tissue) grading system. Gross and microscopic pathology were scored according to the ICRS (International Cartilage Repair Society) scale at 6 months after implantation. The percentage RV at 3 months postoperation was significantly lower in the implanted defects than in the controls, whereas total scores based on the MOCART system were significantly higher in the implanted defects as compared with the controls. Although there were no statistical differences in the gross scores, the average histological scores were significantly higher in the implanted defects than in the controls. To our knowledge, this is the first report to suggest that artificial scaffold‐free 3D‐printed constructs of autologous AT‐MSCs can be aid in the osteochondral regeneration in pigs. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1398–1408, 2019.     

Articular Cartilage Restoration Requires Cells,Scaffolds, Growth Factors,and Mechanical Stimulation

Tissue engineering requires cells, scaffolds, growth factors, and mechanical stimulation. In terms of cartilage restoration or repair, various innovative approaches are evolving, using host or allograft cells, biomimetic scaffolds, matrices, or membranes including hyaluronic acid, as well as diverse biological and growth factors. A current approach for the treatment of chondral or osteochondral defects enhances a microfracture procedure (introducing autologous, mesenchymal stem cells) with dehydrated micronized allograft extracellular matrix (scaffold), platelet-rich plasma (containing anabolic, anticatabolic, and anti-inflammatory growth factors), a fibrin glue sealant, and careful rehabilitation providing mechanical stimulation. Early results are encouraging; long-term outcomes including a larger number of study subjects remain to be reported.     

Combination therapy with intra‐articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit

The present study investigated intra‐articular injection of bone‐marrow‐derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight‐bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra‐articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra‐articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1466–1473, 2015.     

自体骨软骨移植与含富集骨髓干细胞松质骨移植修复兔关节软骨缺损

目的:评价自体骨软骨移植与含富集骨髓干细胞松质骨镶嵌移植两种方法修复全层关节软骨缺损的生物学特征和效果。方法:采用新西兰大白兔制作左右后肢全层软骨缺损模型,分别进行自体骨软骨镶嵌移植、含富集骨髓干细胞松质骨镶嵌移植修复,对照组不作任何修复,每组12只。术后第4、8、12周处死动物取材,分别进行膝关节活动度测定、大体观察、光镜观察与电镜观察。结果:移植实验组在第12周时均能以类透明软骨组织修复缺损,对照组为纤维肉芽组织。形态学检查表明,两种方法均能以类透明软骨组织覆盖缺损,骨软骨移植组无明显免疫排斥现象,随着时间延长,修复高度逐渐增加。骨软骨移植组同含富集骨髓干细胞松质骨镶嵌移植组效果无显著差别。结论:骨软骨移植、含富集骨髓干细胞松质骨镶嵌移植两种方法均能以类透明软骨组织修复全层关节软骨缺损,含富集骨髓干细胞松质骨镶嵌移植更适用于较大面积软骨缺损的修复。     

Repair of superficial osteochondral defects with an autologous scaffold-free cartilage construct in a caprine model: implantation method and short-term results

OBJECTIVE: To compare four different implantation modalities for the repair of superficial osteochondral defects in a caprine model using autologous, scaffold-free, engineered cartilage constructs, and to describe the short-term outcome of successfully implanted constructs. METHODS: Scaffold-free, autologous cartilage constructs were implanted within superficial osteochondral defects created in the stifle joints of nine adult goats. The implants were distributed between four 6-mm-diameter superficial osteochondral defects created in the trochlea femoris and secured in the defect using a covering periosteal flap (PF) alone or in combination with adhesives (platelet-rich plasma (PRP) or fibrin), or using PRP alone. Eight weeks after implantation surgery, the animals were killed. The defect sites were excised and subjected to macroscopic and histopathologic analyses. RESULTS: At 8 weeks, implants that had been held in place exclusively with a PF were well integrated both laterally and basally. The repair tissue manifested an architecture similar to that of hyaline articular cartilage. However, most of the implants that had been glued in place in the absence of a PF were lost during the initial 4-week phase of restricted joint movement. The use of human fibrin glue (FG) led to massive cell infiltration of the subchondral bone. CONCLUSIONS: The implantation of autologous, scaffold-free, engineered cartilage constructs might best be performed beneath a PF without the use of tissue adhesives. Successfully implanted constructs showed hyaline-like characteristics in adult goats within 2 months. Long-term animal studies and pilot clinical trials are now needed to evaluate the efficacy of this treatment strategy.     

Osteochondral repair using an acellular dermal matrix—pilot in vivo study in a rabbit osteochondral defect model

The aim of this pilot project was to introduce a novel use of acellular dermal matrix (ADM) in combination with infrapatellar fat pad mesenchymal stromal cells (IPFP‐MSCs) to effect repair in a rabbit osteochondral defect model. ADM, in a range of surgical procedures, has been shown to promote remodelling of tissue at the site of implantation. Rabbit‐derived ADM (rabADM) was prepared from the skin of donor rabbits. Autologous IPFP‐MSCs were obtained at the time of knee surgery. Osteochondral defects (4 mm cartilage outer/2 mm central bone defect) were drilled into distal femoral condyles of 12 New Zealand White rabbits. Treatments groups: (i) defect only; (ii) rabADM alone; (iii) IPFP‐MSCs alone; and (iv) rabADM with IPFP‐MSCs. Condyles were harvested at 12 weeks, and analyzed using histology, immunohistochemistry (types I and II collagen) and histomorphometry to evaluate osteochondral repair. The rabADM only group achieved the highest ratio of type II to non‐type II collagen (77.3%) using areal measures (similar to normal cartilage), which indicated a higher quality of cartilage repair. The addition of IPFP‐MSCs, with or without rabADM, formed a fibrous collagen cap above the lesion site not seen with rabADM alone. Macroscopically, there was no joint erosion, inflammation, swelling or deformity, and all animals maintained full range of motion. Conclusions: RabADM alone resulted in neocartilage formation similar to native cartilage. IPFP‐MSCs limited osteochondral repair and contributed to fibrosis, even in combination with the rabADM. Further studies using ADM for osteochondral repair are warranted in a more appropriate pre‐clinical model of osteochondral repair. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1919–1928, 2018.

     

Repair of large full‐thickness articular cartilage defects by transplantation of autologous uncultured bone‐marrow‐derived mononuclear cells

The objective of this study was to investigate the feasibility of autologous uncultured bone marrow‐derived mononuclear cell transplantation in large full‐thickness cartilage regeneration. After fixing with a hinged external fixator, the entire surface of the left tibial plateau was resected and large full‐thickness cartilage defects were formed in 48 rabbits. Animals were divided into four groups: autologous uncultured bone marrow‐derived mononuclear cells with fibrin gel (BMC), autologous uncultured peripheral blood‐derived mononuclear cells with fibrin gel (PBC), fibrin gel alone (GEL), or nothing (CON) transplanted to the articular cavity 7 days after the operation. The rabbits were killed 8 or 12 weeks after the operation. The repair of defects was investigated histologically and scored using a histological and histochemical grading scale that was modified from the International Cartilage Repair Society Visual Histological Assessment Scale. To evaluate the regenerated cartilage, we also morphometrically measured the staining area positive for Safranin‐O or type II collagen and calculated the percentages of the positive staining areas with respect to the regenerated soft tissue area. Histological findings showed that the BMC group had superior cartilage repair compared with the other groups, and that the PBC and CON group showed better cartilage repair than did the GEL group. Histological scores and morphometrical measurements also showed the same results quantitively. The transplantation of autologous uncultured bone marrow‐derived mononuclear cells contributes to articular cartilage repair. The easy and safe method used in this study is potentially viable for clinical application. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:18–26, 2008     

组织工程骨-软骨复合体修复犬股骨头负重区大面积骨软骨缺损的实验研究

目的 探讨采用犬股骨头负重区骨和天然软骨制备的骨-软骨双层支架复合成软骨诱导的骨髓间质干细胞(bone marrow mesenchymal stem cells,BMSCs)修复犬股骨头负重区大面积骨软骨缺损的疗效.方法 利用软骨细胞外基质作为软骨支架部分,犬股骨头负重区骨柱经脱细胞处理后作为骨支架部分,采用相分离技术制备骨-软骨双层支架.将成软骨诱导的BMSCs种植到双层支架上体外构建组织工程骨-软骨复合体,并以此修复犬股骨头负重区大面积骨软骨缺损(直径11 mm,高10 mm),第3、6个月时分别取材,行大体、X线片、组织学、Micro-CT和生物力学等检测.结果 X线片及大体观察:3个月时可见股骨头负重区出现轻度塌陷;6个月时出现严重塌陷,呈重度骨关节炎改变.组织学观察:第3、6个月时软骨缺损部分均以纤维组织或纤维软骨充填,周围软骨退变,骨缺损部分不同程度塌陷,与宿主骨质结合紧密.第3、6个月时骨软骨缺损的骨体积分数均低于正常股骨头,差异有统计学意义.6个月时重建软骨下骨的刚度明显低于正常股骨头,差异有统计学意义.结论 结构性骨-软骨双层支架复合成软骨诱导的BMSCs修复犬股骨头负重区骨软骨缺损效果不佳,易导致股骨头塌陷.

Abstract：

Objective To investigate the effects of the novel scaffold on repairing large,high-loadbearing osteochondral defects of femoral head in a canine model.Methods The biphasic scaffolds were fabricated using cartilage extracellular matrix (ECM)-derived scaffold (cartilage layer) and acellular bone matrix (bone layer) by phase separation technique.Articular high-load-bearing osteochondral defects with a diameter of 11-mm and the depth of 10-mm were created in femoral heads.The defects were treated with constructs of a biphasic scaffold seeded with chondrogenically induced bone marrow-derived mesenehymal stem cells (BMSCs).The outcomes were evaluated for gross morphology,histological,biomechanical and micro-CT analysis at the third and sixth month after implantation.Results The gross and X-ray results showed femoral head slightly collapsed at the third month and severely collapse at the sixth month.Histological analysis showed cartilage defects were repaired with fibrous tissue or fibrocartilage with severe osteoarthritis and the varied degrees of the collapse of femoral heads were presented.Micro-CT showed that the values of bone volume fraction in defect area were always lower than those of the normal area in the femoral heads.Biomechanical analysis showed rigidity of the subchondral bone in defect area was significantly lower than that in normal area in the femoral heads at the sixth month.Conclusion The ECM-derived,integrated biphasic scaffold seeded with chondrogenically induced BMSCs could not successfully repair the large high-load-bearing osteochondral defects of the femoral head.