Observation on A-PRF promoting regeneration of osteochondral defects in rabbit knee joints / 上海交通大学学报（医学版）

Objective·To explore the role of advanced platelet-rich fibrin(A-PRF)in osteochondral regeneration.Methods·Bone-marrow mesenchymal stem cells(BMSCs)and knee joint chondrocytes were obtained from New Zealand rabbits.A-PRF was obtained by low-speed centrifugation of the heart blood of rabbits.The histological structure of A-PRF was observed by an optical microscope.The release of growth factors in A-PRF was detected by ELISA,including platelet-derived growth factor,transforming growth factor-β,insulin-like growth factor,vascular endothelial growth factor,epidermal growth factor and fibroblast growth factor.A-PRF's cytotoxicity and capability for promoting the proliferation of rabbit BMSCs were detected by live/dead double staining and MTT methods.The effect of A-PRF on the gene expression of type Ⅱ collagen,aggrecan,alkaline phosphatase(ALP)and osteocalcin(OCN)in rabbit BMSCs was detected by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR).Transwell chambers were used to determine the effect of A-PRF on the migration ability of rabbit BMSCs and the chondrocytes.Rabbit knee osteochondral defect models were established,and 18 rabbits were randomly divided into 3 groups.The A-PRF group(n=6)was implanted with A-PRF in the defect,the A-PRF+BMSCs group(n=6)was implanted with rabbit BMSCs on A-PRF,and the control group(n=6)did not undergo implantation.The rabbits were sacrificed 12 weeks after surgery and the knee joint specimens were stained with hematoxylin-eosin(H-E),toluidine blue and safranin O/fast green.Based on the surface morphology and histology of the knee joints,the International Cartilage Repair Society(ICRS)scoring system was used for macroscopic and histological scoring.Results·A-PRF had a loose network structure and can slowly release growth factors.No cytotoxicity to rabbit BMSCs was observed after adding A-PRF,and the the capability for promoting the proliferation of rabbit BMSCs was significantly increased at 24,48 and 72 h after adding A-PRF(all P<0.05).Chondrogenesis-related gene Ⅱ collagen and aggrecan,as well as osteogenesis-related genes ALP and OCN were significantly up-regulated(all P<0.05).After adding A-PRF,the migration abilities of rabbit BMSCs and chondrocytes were significantly enhanced(both P<0.05),and the migration ability of rabbit BMSCs was significantly higher than that of chondrocytes(P=0.025).The joint surface morphology in the rabbit knee joint defect models was observed.It can be seen that the defects in the A-PRF group and the A-PRF+BMSCs group were basically restored,while the the defects in the control group were only covered by soft tissue.In the ICRS macroscopic score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of the two groups were all significantly higher than those of the control group(all P<0.05).According to the histological results,both the A-PRF group and the A-PRF+BMSCs group formed osteochondral repair,but the cartilage in the A-PRF group was more mature,while the control group formed fibrous repair.In the ICRS histological score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of both the groups were significantly higher than those of the control group(both P<0.05).Conclusion·Autologous A-PRF has good biocompatibility and the capability for promoting the proliferation of BMSCs.It can promote the repair of cartilage and subchondral bone both in vitro and in vivo.

Hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel for repairing rabbit osteochondral defect / 中国组织工程研究

BACKGROUND:Osteochondral defect of the joint is a difficult problem faced by orthopedic surgeons,and traditional repair methods are difficult to obtain satisfactory curative effects.Hydroxyapatite-polyvinyl alcohol-based composite hydrogel material is a direction of current research. OBJECTIVE:To prepare hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel material and characterize its physical characteristics,to verify its histocompatibility and cell adhesion and proliferation ability after implantation in vivo,and explore its repair effect on rabbit osteochondral defects. METHODS:The cylindrical porous poly(lactic acid)scaffold was prepared by 3D printing technology(the pore sizes were 1.2,1.4,1.6 and 1.8 mm,respectively).The poly(lactic acid)scaffold was injected with polyvinyl alcohol and hydroxyapatite mixed emulsion.After freezing thawing and dichloromethane dissolution,hydroxyapatite-polyvinyl alcohol hydrogel was prepared.Then,the collagen-chitosan-gelatin mixture was injected into the hydroxyapatite-polyvinyl alcohol hydrogel and crosslinked with genipin.Finally,the hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel was prepared by alcohol cleaning and freeze-drying.The physical characteristics of the four groups of hydrogels were characterized,and the hydrogels with the best performance were screened for follow-up experiments.Hydroxyapatite-polyvinyl alcohol hydrogel and collagen-chitosan-gelatin composite hydrogel were implanted subcutaneously in SD rats.Hematoxylin-eosin staining and Masson staining were used to observe the adhesion growth of cells on the material surface.Osteochondral defect(diameter:5 mm,depth:6 mm)models were made in the femoral trochlea of bilateral knee joints of 15 rabbits.The composite hydrogel was implanted on the left side(experimental group),while no material was implanted on the right side(control group).Micro-CT and histology were used to evaluate the repair effect of osteochondral defects. RESULTS AND CONCLUSION:(1)Based on the results of porosity,water content,mechanical testing and scanning electron microscopy,it was concluded that the hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel with a pore size of 1.2 mm was more consistent with the general characteristics of natural cartilage,which was used for subsequent experiments.(2)Hematoxylin-eosin staining and Masson staining exhibited that with the extension of subcutaneous implantation time of the materials,the adhesion of cells around the two materials increased significantly,and the proliferation of cells after the implantation of collagen-chitosan-gelatin was better,a large number of cells could be seen growing into the formed network structure,and the network structure was gradually degraded.(3)In the rabbit osteochondral defect experiment,8 weeks after surgery,Micro-CT examination demonstrated that the material implanted in the experimental group had good integration with the surrounding bone-cartilage,with some bone growth on the surface and inside,while the cartilage and subcartilage in the control group still had obvious defects,without effective repair.Hematoxylin-eosin staining and toluidine blue staining displayed that the composite hydrogel in the experimental group integrated with the surrounding articular cartilage 4-8 weeks after implantation.With the extension of time,new cartilage gradually formed on the surface of the material.At 12 weeks,most of the defect was covered by new cartilage,and good bone growth was also observed in the subcartilage.In the control group,the deep bone defects were mostly repaired and the superficial cartilage and subchondral bone defects were also repaired to a certain extent,but they were mainly replaced by fibrous tissue and part of fibrocartilage 12 weeks after surgery.(4)In conclusion,hydroxyapatite-polyvinyl alcohol/collagen-chitosan-gelatin composite hydrogel material can mimic the structure and function of natural cartilage,and can effectively repair osteochondral defects in animal experiments.

Repair of infected osteochondral defect with sustained release vancomycin three-dimensional scaffold in rabbits / 中国组织工程研究

BACKGROUND:A large number of studies have confirmed that tissue engineering scaffolds can almost completely repair osteochondral defects.However,when osteochondral defects are complicated with infection,even after thorough debridement in the early stage,the repair effect of simple osteochondral tissue engineering scaffolds is often unsatisfactory. OBJECTIVE:To prepare fibroin/chitosan/nano-hydroxyapatite scaffold loaded with vancomycin hydrochloride sustained release microspheres,and to investigate the repair effect on infected osteochondral defect in distal femur of rabbit. METHODS:(1)Vancomycin hydrochloride sustained release microspheres were prepared by emulsified solvent evaporation method.The sustained-release microspheres of different weights(7.5,10,and 12.5 mg)were mixed with fibroin protein-chitosan nanohydroxyapatite solution,and the scaffolds of fibroin protein/chitosan/nano-hydroxyapatite were prepared by chemical crosslinking method.The porosity,water absorption and expansion rate,hot water loss rate of the scaffolds,and drug sustained-release in vitro were characterized.(2)Forty-five New Zealand white rabbits were randomly divided into blank group,control group,and experimental group,with 15 rabbits in each group.The osteochondral defect and infection model of the distal femur of the right hind limb was established in both groups.The blank group was not treated,and the control group was implanted with fibroin protein-chitosan-nano-hydroxyapatite scaffold.Vancomycin hydrochloride sustained-release microspheres(10 mg)of fibroin/chitosan/nano-hydroxyapatite scaffold were implanted in the defect of the experimental group.The levels of C-reactive protein and leukocytes in blood samples were detected 1 week after operation.At 4,8 and 12 weeks after operation,the tissue of the operative area was taken for gross observation and pathological observation. RESULTS AND CONCLUSION:(1)With the increase of sustained-release microspheres content,the porosity of scaffolds decreased,and there was significant difference among groups(P＜0.05).There were no significant differences in the pore size,water absorption expansion rate and hot water loss rate among the three groups(P＞0.05).Vancomycin hydrochloride was released sustainably in vitro for more than 30 days in all three groups of scaffolds.(2)The levels of C-reactive protein and leukocytes in blood samples of the experimental group were lower than those of the blank group and control group(P＜0.05).The repair of gross cartilage in the experimental group was significantly better than that in the blank group and the control group.Hematoxylin-eosin,Masson,Alcian blue and type Ⅱ collagen immunohistochemical stainings showed that the osteochondral repair effect of the experimental group was significantly better than that of the blank group and the control group at each time point.(3)The results showed that fibroin/chitosan/nano-hydroxyapatite scaffolds loaded with vancomycin hydrochloride sustained-release microspheres could effectively promote the repair of open osteochondral defects.

Tissue engineering methods for repair of articular cartilage defect under special conditions / 中国组织工程研究

BACKGROUND: Although desired cartilage repair has been realized via tissue engineering technology, these achievements mainly focus on small-size defect under a normal physical condition. However, cartilage defects are always accompanied by the underlying diseases in clinical practice, such as osteoarthritis and rheumatoid arthritis. Meanwhile, the location, scope, and depth of cartilage defects are uncertain, which brings a great challenge in cartilage tissue repair. OBJECTIVE: To summarize the methods of repairing articular cartilage defects at different locations and under inflammatory condition. METHODS: We searched PubMed and CNKI with the search terms “cartilage defect regeneration, osteochondral, growth plate, weight-bearing area, inflammatory” in Chiense and English to retrieve related papers published before March 2019. A total of 209 papers were retrieved and 86 were included in the final analysis according to inclusion and exclusion criteria. RESULTS AND CONCLUSION: For articular cartilage defects under different special conditions, the repair goals and strategies are different. For repair of full-layer cartilage defects and osteochondral structure defects, multi-layered scaffolds are often used to repair the unique stratified cartilage structure and subchondral bone structure, while avoiding the problem of heterotopic ossification in neonatal cartilage. To avoid deformity after long bone maturation, growth factors such as insulin-like growth factor and bone morphogenetic protein 7 should be added to continuously stimulate the repair of the growth plate and promote bone growth. For cartilage repair in the weight-bearing area, the scaffolds should have good mechanical property, which ensure not to undergo severe deformation and structural damage when loaded. In addition, the new cartilage tissue has sufficient mechanical strength to support sustained longitudinal pressure and wear. For cartilage defects in the inflammatory state, both inflammation management and cartilage defect repair should be considered, and introduction of mesenchymal stem cells can regulate immune function and promote tissue regeneration, such that articular cartilage defect can be completely repaired.

Repair of Osteochondral Defects in Rabbit Knee Using Menstrual Blood Stem Cells Encapsulated in Fibrin Glue: A Good Stem Cell Candidate for the Treatment of Osteochondral Defects

BACKGROUND: In recent years, researchers discovered that menstrual blood-derived stem cells (MenSCs) have the potential to differentiate into a wide range of tissues including the chondrogenic lineage. In this study, we aimed to investigate the effect of MenSCs encapsulated in fibrin glue (FG) on healing of osteochondral defect in rabbit model. METHODS: We examined the effectiveness of MenSCs encapsulated in FG in comparison with FG alone in the repair of osteochondral defect (OCD) lesions of rabbit knees after 12 and 24 weeks. RESULTS: Macroscopical evaluation revealed that the effectiveness of MenSCs incorporation with FG is much higher than FG alone in repair of OCD defects. Indeed, histopathological evaluation of FG + MenSCs group at 12 weeks post-transplantation demonstrated that defects were filled with hyaline cartilage-like tissue with proper integration, high content of glycosaminoglycan and the existence of collagen fibers especially collagen type II, as well as by passing time (24 weeks post-transplantation), the most regenerated tissue in FG + MenSCs group was similar to hyaline cartilage with relatively good infill and integration. As the same with the result of 12 weeks post-implantation, the total point of microscopical examination in FG + MenSCs group was higher than other experimental groups, however, no significant difference was detected between groups at 24 weeks (p>0.05). CONCLUSION: In summary, MenSCs as unique stem cell population, is suitable for in vivo repair of OCD defects and promising for the future clinical application.

Estrogen promotes spontaneous repair of osteochondral defect via inhibition of osteoclast activity / 中华创伤杂志

Objective To investigate the role of estrogen in spontaneous repair of osteochondral defect,so as to provide guidance for the application of estrogen in tissue engineering.Methods Seventytwo healthy adult female SD rats (4-month-old) were assigned to negative control group (group A,n =24),ovariectomized group (group B,n =24) and ovariectomized + estrogen treatment group (group C,n =24) according to the random number table.Rats in group C were intraperitoneally injected 0.1 mg/kg estradiol benzoate once per week after operation.An osteochondral defect model (diameter:2 mm,height:1.5 mm) was established in femoral trochlea of rats 4 weeks after operation.At 2,10 and 20 weeks after the modeling,8 rats from each group were sacrificed.Femoral condyles were collected to measure bone volume fraction (BVF),number of bone trabeculae (Tb.N),trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp) in the osteochondral defect area by micro-CT scanning.Morphological changes were observed by HE staining,histomorphological changes and cartilage regeneration by safranine O-fast green staining,osteoclast count by tartrate-resistant acid phosphatase (TRAP) staining,distribution of matrix metalloproteinase-9 (MMP-9) by immunohistochemistry and expressions of osteoprotegerin (OPG),receptor activator of nuclear factor-κB ligand (RANKL) and MMP-9 by real-time-PCR.Results Compared to group B,increased BVF and Tb.N and decreased Tb.Sp were observed in groups A and C at each time point.More bone matrix formations were observed in groups A and C than in group B at 2 weeks,cysts (also known as cystic cavities) in regenerated subchondral bone and cracks in subchondral bone plate were observed in group B at 10 and 20 weeks,and proliferation of osteoclasts was active within lesions in group B at 10 and 20 weeks.Compared to group B,lowered levels of RANKL and MMP-9 (P ＜ 0.05) and significantly increased level of OPG (P ＜ 0.01) were observed in groups A and C at each time point,and osteoclast count in groups A and C was lowered at 10 and 20 weeks (P＜0.05).No regeneration of cartilage layer was observed in all groups.Conclusions Excessive proliferation of osteoclasts results in formation of cystic cavities and cracks.Estrogen improves the speed and quality of bone repair by regulating activities of osteoblasts and osteoclasts,so it can be used to treat osteochondral defect in tissue engineering.

Therapeutic Effects of Mesenchymal Stem Cells and Hyaluronic Acid Injection on Osteochondral Defects in Rabbits' Knees

PURPOSE: To evaluate the treatment results of intraarticular injection according to the frequency of hyaluronic acid with mesenchymal stem cells on the osteochondral defect of rabbits' medial femoral condyles. MATERIALS AND METHODS: A 5 mm diameter and 4 mm depth osteochondral defect was made on the medial femoral condyles of 18 rabbits, divided into six groups. One week after osteochondral defect, group B was injected intraarticularly with hyaluronic acid (HA), group C with mesenchymal stem cells (MSCs), and group D, E and F with both HA and MSCs. Group E and F received second HA injection a week after. Further, group F received third HA injection in the third week. RESULTS: In a macroscopic evaluation, groups B (6; range, 5-8), C (6; range, 6-7), D (7; range, 6-7), E (6.5; range, 6-8) and F (7.5; range, 6-8) showed statistically significant improvements in osteochondral defect healing, compared with that of group A (4; range, 3-5) (p=0.002). In histological evaluation, groups B (11.5; range, 11-13), C (13; range, 12-18), D (16; range, 13-18), E (17.5; range, 13-20), and F (19.5; range, 12-22) showed statistically significant differences in osteochondral defect healing, compared with group A (8; range, 6-9) (p=0.006). CONCLUSIONS: The intraarticular injections of MSCs or HA can play an effective role during the healing osteochondral defects in rabbits.

Osteochondral Autograft Using Head of Proximal Phalanx of Toe for Partial Osteochondral Defect of Proximal Interphalangeal Joint: A Case Report

Osteochondral injury due to the trauma of the hand is relatively common. If the size of the osteochondral fracture fragment is large, open reduction and internal fixation are often feasible in treating these problems. However, arthroplasty using osteochondral graft is more preferred when the particle is small and articular surface is comminuted or fully defected. There are many reports of osteochondral graft using the costal osteochondral graft but the osteochondral graft using the interphalangeal joint of the toe is rarely reported. Thoroughly reviewed with relevant articles, this report presents a case of a 33 year old male who was successfully treated with osteochondral autograft using the proximal interphalangeal joint of the toe due to the traumatic osteochondral defect in the head of the second proximal phalanx.

Mosaicoplastia revestida com periósseo no tratamento de perda osteocondral do joelho / Mosaicplasty with periosteal gratf for resurfacing local full-thickness chondral defects of the knee

Introdução e Objetivos: Existem várias formas de tratamento das perdas extensas de substância osteocondral (OC), entre elas, a mosaicoplastia recoberta com periósseo (mosaicambium). Neste trabalho pretende-se avaliar os resultados clínicos a médio dos doentes com defeito osteocondral tratados por esse método. Métodos: Vinte joelhos com defeito osteocondral superior a 2cm2 foram operados entre 1999 e 2005, com recurso a duas técnicas cirúrgicas (mosaicoplastia/mosaicambium). Todos os doentes foram avaliados em pré-operatório clinicamente (escalas ICRS,VAS), radiograficamente e com RM. No ano de 2008 todos foram revistos e avaliados seguindo os mesmos critérios. Os casos foram distribuídos em dois grupos consoante o tipo de tratamento.A avaliação estatística recorreu ao programa informático EPI2000. Utilizou-se o teste do qui-quadrado para variáveis categoriais e o teste t de Student para variáveis contínuas. Aceitou-se como erro alfa um valor de 0,05. Tipo de estudo: Estudo clínico, retrospectivo, nível de evidência 4. Resultados: Antes, todos os doentes estavam nos grupos ICRS C e D. Em 2008, 18 doentes estavam nos grupos A e B (12 no grupo A). Comparando os resultados entre grupos (mosaicoplastia/mosaicambium), não houve diferenças significativas entre os grupos. Radiograficamente, não existiam alterações em 55% dos casos. Discussão: Sem diferenças clínicas, por que a opção mosaicambium? A morbilidade nas zonas dadoras não é desprezível. A opção mosaicambium recorreu a menos cilindros OC, reduzindo a morbilidade resultante. Conclusão: A técnica mosaicambium é uma boa opção alternativa para perdas de substância OC com mais de 2 cm2.

Introduction and Objectives: Clinical and functional assessment comparing cases of full-thickness chondral defects (OC) treated with mosaicplasty or mosaicplasty covered with periosteum (mosaicambium). Methods: 20 knees with chondral defect, (10 mosaicplasty/10 mosaicambium) were operated between 1999 and 2005. All patients were clinically assessed preoperatively using the ICRS scale, VAS scale, X-ray and MRI. During 2008, we reviewed patients using the sameprotocol. For statistical purposes, the patients were divided into two groups, according to the surgical technique. Statistical analysis was performed with EPI2000 program, using chi-squared test and Student's t test, with a significance level of 0.05. Results: Preoperatively, all patients were in group C /D (ICRS scale). In 2008, 18 cases were in groups A and B according to the ICRS scale (12 in A). Between groups, there were no statistical differences. The X-ray study revealed nochanges in 55% of cases. Discussion: With no differences, why mosaicambium option? Morbidity on graft donor zones is not negligible. Mosaicambium uses less chondral grafts, reducing the potential for morbidity at graft donor zones. Conclusion: The mosaicambium technique is an excellent alternative forchondral defects greater than 2 cm2.

Tratamento dos defeitos osteocondrais do joelho / Treatment of the knee osteochondral defects

Os defeitos osteocondrais do joelho acometem toda a espessura da cartilagem e são geralmente de origem traumática, podendo ocorrer isoladamente ou em conjunto com lesões ligamentares ou meniscais. O diagnóstico definitivo geralmente é feito por ressonância magnética, apesar da história e exame físico darem indícios do diagnóstico. As lesões osteocondrais sintomáticas necessitam de tratamento cirúrgico e a escolha da técnica cirúrgica depende de alguns fatores como tamanho da lesão, local da lesão, atividade e idade do paciente. Técnicas, como abrasão e drilling são pouco usadas atualmente. A microfratura é largamente usada e geralmente é a primeira escolha no tratamento de defeitos osteocondrais de 1 a 2,5 cm2. A mosaicoplastia também pode ser usada para lesões desta magnitude, mas em pacientes mais ativos que necessitam um retorno mais rápido às atividades esportivas. Pode também ser usadas em defeitos maiores, porém o transplante autólogo de condrócitos (TAC) aparece como uma boa opção para lesões maiores. A primeira geração do TAC transplanta condrócitos os quais ficam contidos no defeito devido a uma cobertura de periósteo, já a segunda geração de TAC apresenta os condrócitos embebidos em uma matriz e evita o uso da cobertura com periósteo. O transplante alógeno osteocondral também é uma opção para defeitos maiores que 4 cm2. Novas tecnologias estão sendo desenvolvidas, porém ainda sem aplicabilidade clínica.

Autogenous Osteochondral Grafting for Treating Osteochondral Defect of the Femoral Condyle of the Knee Joint / 대한정형외과학회잡지

PURPOSE: We wanted to evaluate the outcomes of an autologous osteochondral graft (Mosaicplasty) for treating chondral defects of the femoral condyle and We assessed the factors affecting the clinical results. MATERIALS AND METHODS: This study enrolled 18 patients (19 cases) who underwent an autogenous osteochondral graft to treat a osteochondral defect in the femoral condyle from July 2000 to June 2006. The average age was 26.2 years old (age range: 16-48 years old). Among the patients, 17 cases were men. In 14 cases, the osteochondral defects were localized in the medial femoral condyle and only 5 cases showed a defect in the lateral femoral condyle. The average size of the osteochondral defects was 4.2 cm2 (1-13 cm2). The Lysholm knee scoring scale and the Tegner's activity score were applied for clinical evaluation. Further, we carried out simple X-ray for all the cases and we performed MRI in 5 cases for the radiological evaluation. Tthe factors affecting the clinical results were also analyzed and the complications were evaluated. RESULTS: The average follow-up period was 22 months (range: 6-55 months). Eighten out of 19 cases (94.7%) were able to return to ordinary life. The Lysholm knee scoring scale and the Tegner's activity score indicated much better clinical results for small lesions and for young patients. For the radiological results, all the cases displayed a decrease in the size of radiolucent zones on the follow up X-ray. Among the 5 cases for which an MRI was performed, graft unions were observed in 3 cases, but 2 cases displayed continuous peri-graft edema. Any other complications involving the donor and recipient site were not observed. CONCLUSION: We conclude that autogenous osteochondral grafting is useful for specific patients depending on the size of the lesion and the patient's age. It is a valuable treatment option for osteochondral defects in the knee joint.

Experimental study of treating osteochondral defects with osteochondral composites constructed in vivo / 中国矫形外科杂志

[Objective]To evaluate the effect of treating the osteochondral defects with implanted cell-scaffold composites,cultured MSCs as seed cells and PLGA as scaffolds,and to acquire desirable seed cells and scaffold materials.[Method]BMSCs were induced to differenciatiated into chondrocytes,co-cultured with PLGA scaffold respectively in vitro,then implanted into osteochondral defects on canine models by using techniques of mosaicplasty,induced BMSC-PLGA scaffold composites in the top of the defect and BMSC-PLGA scaffold composites in the bottom of the defect,osteochondral composites were constructed in vivo,and repair was observed with naked eyes and histology.[Result]At 16 weeks after transplantation the defects of expeirmental group were covered with semi-transparent smooth white tissue and the margins between the repair tissue and the surrounding cartilage were not recognized.Histologically,most of the repair tissue was consisted with chondrocytes,maintained their thickness to the full depth of the original defects.The subchondral bone was well remodeled.The tidemark was observed.The defects of positive control group were covered with repair tissues,and partial were conformed with original cartilage.The repair tissue was partly filled with chondrocytes.However,the defects of negative control group were repaired with soft fibrous tissues without luster,and an obvious boundary between reparative and original cartilage was seen.[Conclusion]MSCs-PLGA scaffold composites,constructed into osteochondral composites by suppressing closely in vivo,are the ideal materials for repairing cartilage defects.

Repair of Osteochondral Defect Using Chitosan-collagen Sponge intheRabbit's Knee / 대한정형외과학회잡지

PURPOSE: To determine the suitability of using a chatoyant-collagen sponge as a scaffold for transplanting a chondrocyte into a full-thickness articular cartilage defect. MATERIALS AND METHODS: The in vitro characterization of a chatoyant-collagen sponge infiltrated with the chondrocyte was combined with an in vivo assessment of the early articular cartilage repair in a rabbit's knee by H&E and MTT staining. These porous chatoyant-collagen sponges were implanted into the osteochondral defects made in the left patellofemoral grooves of 12 rabbits. The osteochondral defects were untreated in the right side and used as controls. The experimental animals were sacrificed 1, 3, 6 and 12 weeks after implantation and the repaired tissue was evaluated by a gross and histological evaluation using the Wakitani score. RESULTS: More primary cells cultured from the articular cartilage of the rabbit's knee were found to attach to and survive within a porous chatoyant-collagen sponge than with a chatoyant sponge. In gross and histological examination, the experimental group showed indications of repair, which appeared similar in color and texture to the surrounding articular cartilage. The Wakitani scoring in the experimental group at 6 (Ave. 10.7) and 12 (Ave. 7.3) weeks were superior to those in the control group at 6 (Ave. 8.7) and 12 (Ave. 3.7) weeks (6 wk: p=0.03, 12 wk: p=0.02). CONCLUSION: Scaffolds composed of porous a chatoyant-collagen sponge enhance the growth of cartilaginous repair and make a milieu for the survival of chondrogenic cells both in vitro and in vivo.

Treatment of Osteochondral Defects with Perichondrial Cells Embedded in Alginate Beads in Rabbit / 대한정형외과연구학회지

PURPOSE: The objective of this study was to investigate the use of cultured rib perichondrial cells embedded in alginate bead on healing in a rabbit osteochondral defect model. The degree of articular cartilage repair was evaluated histologically, histomorphometrically, and biochemical characteristics of the neocartilage. MATERIALS AND METHODS: A single defect, 3.5 mm wide by 3 mm deep, was created in the weight bearing area of the medial femoral chondyle in thirty New Zealand rabbits. The right defect filled with two alginate beads embedded with rabbit rib perichondrial cells, the left defect was empty as the control. The animals were killed at 1, 3, and 12 months, and the repair tissues were examined histologically, and histomorphometric differences were evaluated by an image analysis system. The defects also were examined biochemically for the glycosaminoglycan (GAG) and type II collagen to compare the results with normal articular cartilage. RESULTS: The attachment of repair tissue with the surrounding host tissue was incomplete, many specimens exhibited degenerative changes in adjacent tissue over a post transplant time period. Histomorphometric results showed that the repair groups (0.24+/-0.11 mm, -26.97 (25.62 mm) was decreased in surface roughness, and depression than controls (0.32+/-0.06 mm, -48.73 (32.59 mm) at 12 months. Repair area, repair area ratio, and repair thickness of the repair groups (6.89+/-2.1 mm2, 39.5+/-19.5%, 0.11 (0.01 mm) were increased than controls (2.65+/-2.35 mm2, 2.85+/-2%, 0.09+/-0.04 mm) at 12 months. After 12 months, the content of GAGs of neocartilage (36.45 microgram/mg) was similar to those of normal artilcular cartilage (36.74 microgram/mg), the percentage of type II collagen of the neocartilage increased up to 95%. CONCLUSION: Transplanted rib perichondrial cells were seen to proliferate to fill the osteochodral defect with neocartilage. Histomorphometric analysis should allow a more quantitative described the degree of articular cartilage repair.

An Experimental Study about the Effects of TGF - 1 and Autogenous Periosteal Graft on Healing of Osteochondral Defect in Rabbit / 대한정형외과학회잡지

Articular cartilage is a highly differentiated tissue, lacking a vascular supply and having only limited regenerative capability. Cut or other mechanical damage restricted to the cartilage does not repair. Experimentally and clinically, cartilage defect that penetrate the subchondral bone undergoes repair through the formation of tissue usually characterized as fibrous, fibrocartilaginous or hyaline-like cartilaginous tissue. There is little definitive informations about local or systemic factors that control the differentiation of mesenchymal cells to osteoblast, chondroblast or fibroblast. Our study was designed to evaluate the effect of transforming growth factor-beta (TGF-pl) and autogenous periosteal graft on the healing of osteochondral defect of distal femur of rabbit and also the possibility of these method to be clinically applicable to human. The experimental model used in the present study for including cartilage in rabbit was based mainly on the model used by Frukawa et al14). in rabbit. A full thickness osteochondral defect of 80 rabbit were made with 2mm diameter of drill-bit and electrically driven drill. Experimental animals were divided into four group: 1) group I, osteochondral defect only, 2) group II, osteochondral defect with infiltration of phosphate buffer solution, 3) group III, osteochondral defect with infiltration of TGF-Bl, 4) group IV, osteochondral defect with autogenous periosteal graft. The healing of the defect was assessed at 1 week, 3 weeks, 5 weeks, 12 weeks after operation by gross and histochemical examination. At 1 week, fibrinoid material in edge to edge arcade arrangement was present in group I,II,III,IV. At 3 weeks, spindle shaped undifferentiated mesenchymal cell present in the periphery of fibrinous network, but there is no appearance of mesenchymal cell in group I,II. At 5 weeks, essentially complete repopulation of the defect with progressive differentiation of cells to chondroblast, chondrocyte, osteoblast and synthesis of cartilage and matrix in their appropriate location in group III and IV were found. At 12weeks, hyaline like cartilage formation was observed in group III and IV. but early trace of degeneration of the cartilage were seen in many defect with the prevalence and intensity of the degeneration increasing at group I and 3 . Our study demonstrated in detail the repair of full-thickness defect in rabbit articular cartilage extending into cancellous bone of the marrow cavity under influence of local growth factor (TGF-pl) and autogenous periosteal graft. Excellent reconstruction of articular cartilage was observed in TGF- Bl infiltration group and autogenous periosteal graft group as early as 5 weeks after the creation of defect. Although the further study should be carried out for their clinical application, we conclude that TGF-Bl regulates the overall mechanism of matrix constituent in connective tissue and autogenous periosteal graft have a chondrogenic potential to repair major osteochondral defect. these suggest that TGF-Bl and autogenous periosteal graft may be a important pathophysiological regulator of chondro- genesis.

Repair of Osteochondral Defect Using Grafts of Cultured Chondrocytes in Rabbits / 대한정형외과학회잡지

Chondrocytes isolated from the articular cartilage of rabbit knee joint were cultured in vitro within fibrin glue carrier for 2 weeks. Histochemical and electromicroscopical approaches were used to study chondrocytes behavior and phenotypic expression. In vitro study, chondrocyte assumed a rounded morphology, accumulated metachromatic matrix and took on the cytological characteristics of in vivo cartilage cells. Allogenic cultured chondrocyte in fibrin glue was transplanted into osteochondral defect in rabbit joint. The contralateral knee joint served as a control in which the defect was left empty. This in vivo study was performed for the investigation of the chondrogenic potential of cultured chondrocytes embedded in fibrin glue. Grafted defects was filled with cartilage in gross finding, repaired tissue consisted of differentiated chondrocytes and matrix resumed that of hyaline cartilage. At sixteen week after transplantation, subchondral region was partially transformed into bone without loss of overlying articular cartilage, but in control group, defect did not heal successfully. Repaired articular cartilage was thicker than host cartilage and tide mark was not shown up to 24 weeks. Some of repaired tissue was degraded partially. These results suggest that fibrin glue provides suitable environment for differentiation of chondrocyte and allograft of cultured chondrocyte in fibrin glue transplanted into large osteochondral defect improves cartilage repair.