Osteochondritis dissecans剥脱性骨软骨炎

Sub-articular,post-traumatic necrosis Occurs only on convex surfaees of bone Medial condyle of femur Capitellum Proximal surface of talus Head of 1st metatarsal Most patients are athletic Direct blow is more common cause than a rotational injury 医学词汇注释与简要讲解Medial condyle内侧髁Capitellum肱骨小头胫骨近端关节面 metatarsal

Osteochondritis dissecans of the capitellum in adolescents

Osteochondritis dissecans(OCD)is a disorder of articular cartilage and subchondral bone.In the elbow,an OCD is localized most commonly at the humeral capitellum.Teenagers engaged in sports that involve repetitive stress on the elbow are at risk.A high index of suspicion is warranted to prevent delay in the diagnosis.Plain radiographs may disclose the lesion but computed tomography and magnetic resonance imaging are more accurate in the detection of OCD.To determine the best treatment option it is important to differentiate between stable and unstable OCD lesions.Stable lesions can be initially treated nonoperatively with elbow rest or activity modification and physical therapy.Unstable lesions and stable lesions not responding to conservative therapy require a surgical approach.Arthroscopic debridement and microfracturing has become the standard initial procedure for treatment of capitellar OCD.Numerous other surgical options have been reported,including internal fixation of large fragments and osteochondral autograft transfer.The aim of this article is to provide a current concepts review of the etiology,clinical presentation,diagnosis,treatment,and outcomes of elbow OCD.

Subchondral bone as a novel target for regenerative therapy of osteochondritis dissecans:A case report

BACKGROUND Osteochondritis dissecans(OCD)is a rare disease of unclear cause characterized by subchondral bone damage and overlying cartilage defects.The current report presents the results of subchondral bone as a novel target for implantation of peripheral blood stem cells(PBSCs)in the treatment of OCD.CASE SUMMARY A 16-year-old patient diagnosed with OCD underwent subchondral bone implantation of PBSCs.Four months later,the patient's visual analog scale scores,Western Ontario and McMaster University osteoarthritis index,and whole-organ magnetic resonance imaging score improved significantly,and regeneration of cartilage and subchondral bone was observed on magnetic resonance imaging.CONCLUSION This is the first case of OCD treated with subchondral bone as an implantation target of PBSCs,which highlights the importance of subchondral bone for cartilage repair.This treatment could be a potential option for articular cartilage and subchondral bone recovery in OCD.

Treatment of knee osteochondritis dissecans with autologous tendon transplantation:Clinical and radiological results

BACKGROUND Defect treatment with tendon autograft in osteochondral lesions has been published in the literature with an experimental study in dogs.To demonstrate that it is possible to treat knee osteochondral lesions with the technique of autologous tendon transplantation.AIM To evaluate the clinical and radiological results of patients with knee osteochondral lesions who were treated with autologous tendon transplantation.METHODS Twenty patients(22 knees)with osteochondritis dissecans(OCD)lesions involving the knee were treated with autologous tendon transplantation between 2005-2018.All lesions were International Cartilage Repair Society grade IV.All patients were evaluated clinically at final follow-up with knee injury and osteoarthritis outcome score(KOOS);and radiologically with magnetic resonance observation and cartilage repair tissue(MOCART)and Kellgren-Lawrence(KL)classification.RESULTS A total of 20 patients(22 knees)with a mean age of 25.5±6.8 years were included.The average defect size was 4.2±2.1 cm^(2),and the average defect depth was 0.9±0.4 cm.Total KOOS score was preoperatively 29.4±5.5 and was later found to be 81.5±5.9 after an average of 68.7±37.7 mo follow-up.The mean MOCART score was 56.2±10.7.Preoperatively,all of the patients had KL grades of 0-1;during the follow-up period,80% of the patients showed no radiological progress of osteoarthritis.Patients with less than 4 cm^(2) lesion had statistically significantly better overall KOOS than patients whose more than 4 cm^(2) lesion,particularly in sport and quality of life subscales.CONCLUSION The autologous tendon transplantation is a single-step,safe,simple,cost-effective method for the treatment of knee OCD with satisfactory clinical and radiological outcomes,particularly in patients with less than 4 cm^(2) lesion.

Abnormal Femoral Origin of the Anterior Cruciate Ligament Associated with Osteochondritis Dissecans of the Medial Femoral Condyle

We report a case of abnormal meniscal-like anterior cruciate ligament (ACL), inserting at the 9 o’clock position just beside the cartilage of the lateral femoral condyle, in a stable knee associated with osteochondritis dissecans (OCD) of the medial femoral condyle.

In Situ Deposition of Drug and Gene Nanoparticles on a Patterned Supramolecular Hydrogel to Construct a Directionally Osteochondral Plug

The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.

High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

A bibliometric analysis and visualization of osteochondral lesions of talus (2004-2021)

Background:Osteochondral lesions of the talus(OLTs)are a significant challenge for foot and ankle specialists,which could cause pain and decrease patient function.Researchers can use the findings of this study to shape future directions for research by exploring global trends and hotspots in OLT.Methods:Web of Science Core Collection was used to retrieve literature related to OLT between 2004 and 2021.This report covers the current state of OLTs,such as publications,journals,trends,hotspots,and the performances of relevant countries,institutions and authors.The co-citation analysis,the coauthorship analysis,the cooccurrence analysis,and the bibliographic coupling analysis were conducted with the Bibliometrix R package,VOSviewer v1.6.10.0,and CiteSpace 5.8.R3.Results:During an 18-year review,717 articles and 76 review articles on OLT published from 2004 to 2021 were reviewed.The USA has made the largest contribution to the OLT-related literature,and a significant contribution has been made by Kennedy JG(48/6.05%)and van Dijk CN(30/3.78%).In terms of total link strength,Foot&Ankle International was the leading journal.Analysis showed that the global research hotspots of OLTs focused on the pathogenesis,diagnosis,clinical research,and surgical treatment of OLT.It would be significant to pay close attention to future research on osteochondral autograft transplantation and management,surgery,multidisciplinary integration and mechanisms of OLT,and its related diseases.Conclusions:The study provides information about the current status and hotspots of research in the domain of OLT over the past 18 years that will assist researchers in identifying potential perspectives on hot topics and research frontiers.

Alginate/gelatin/boron-doped hydroxyapatite-coated Ti implants:in vitro and in vivo evaluation of osseointegration

In this study,boron-doped hydroxyapatite(BHT)-loaded alginate/gelatin-based(A/G)hydrogel coating on Ti was fabricated to support bone integration through triggering osteoinduction,vascularization and immunomodulation.Initially,highly reproducible,cheap and time-effective BHT was produced,which significantly promoted higher osteogenic and angiogenic maturation,while a mild innate immune response was observed.The immense potential of BHT was evidenced by the production of a gap-filling A/G/BHT interphase on Ti implants to mimic the osseous extracellular matrix to achieve functional bridging and exert control over the course of innate immune response.We initially aminosilanized the implant surface using 3-aminopropyl triethoxysilane,and then coated it with 0.25%w/v alginate with 20 mM 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to allowthe A/G/BHT pre-gel to disperse evenly and covalently attach on the surface.The pre-gel was added with 0.2 M NaCl to homogeneously blend BHT in the structure without inducing ionic crosslinking.Then,the coated implants were freeze-dried and stored.The coated layer demonstrated high cohesive and adhesive strength,and 8-month-long shelf-life at room temperature and normal humidity.The A/G/BHT was able to coat an irregularly shaped Ti implant.Osteoblasts and endothelial cells thrived on the A/G/BHT,and it demonstrated greatly improved osteogenic and angiogenic capacity.Moreover,A/G/BHT maintained macrophage viability and generated an acute increase in immune response that could be resolved rapidly.Finally,A/G/BHT was shown to induce the robust integration of implant in a rabbit femur osteochondral model within 2months.Therefore,we concluded that A/G/BHT coatings could serve as amultifunctional reservoir,promoting the strong and rapid osseointegration of metallic implants.

3D printing of patient-specific implants for osteochondral defects: workflow for an MRI-guided zonal design

Magnetic resonance imaging(MRI)is a common clinical practice to visualize defects and to distinguish different tissue types and pathologies in the human body.So far,MRI data have not been used to model and generate a patient-specific design of multilayered tissue substitutes in the case of interfacial defects.For orthopedic cases that require highly individual surgical treatment,implant fabrication by additive manufacturing holds great potential.Extrusion-based techniques like 3D plot-ting allow the spatially defined application of several materials,as well as implementation of bioprinting strategies.With the example of a typical multi-zonal osteochondral defect in an osteochondritis dissecans(OCD)patient,this study aimed to close the technological gap between MRI analysis and the additive manufacturing process of an implant based on dif-ferent biomaterial inks.A workflow was developed which covers the processing steps of MRI-based defect identification,segmentation,modeling,implant design adjustment,and implant generation.A model implant was fabricated based on two biomaterial inks with clinically relevant properties that would allow for bioprinting,the direct embedding of a patient’s own cells in the printing process.As demonstrated by the geometric compatibility of the designed and fabricated model implant in a stereolithography(SLA)model of lesioned femoral condyles,a novel versatile CAD/CAM workflow was successfully established that opens up new perspectives for the treatment of multi-zonal(osteochondral)defects.

Fabella Syndrome: A Typical Case of Misdiagnosis and Discussion

Background: Fabella is a natural occurring sesamoid bone, cartilage or a mixture of both that is usually located at the posterolateral corner (PLC) of the knee [1]. Recently the PLC of the knee has been extensively investigated because it is a common site of injuries and diseases [2] [3]. The complexity of PLC anatomy needs to be fully understood because the fabella could be missed diagnosis as an osteochondral defect, osteochondritis dissecans (OCD), calcific tendinitis, or foreign body. We present a case report of fabella syndrome triggered by trauma and also performed a review of literature for the various diagnoses that might be confused with fabella syndrome. Case presentation: A 29-year-old, Sudanese male presented to the trauma center in King Khalid Hospital in KSA, complaining of pain and partial swelling in his left knee joint due to trauma. Fabella was detected in the posterior lateral corner (PLC) of the knee joint embedded in the lateral head of the gastrocnemius muscle. All other pathological conditions were excluded. Conclusion: Fabella is sesamoid bone with variable size, found in the PLC. Commonly if present it causes periodic pain especially in the fully extended knee or it remains asymptomatic. Trauma, surgery, sports or heavy extreme activities may trigger the pain of asymptomatic fabella. Clinicians should consider that pain in the PLC of the knee can result from the presence of the fabella in a condition called fabella syndrome.

Current management of talar osteochondral lesions

Osteochondral lesions of the talus(OLT) occur in up to 70% of acute ankle sprains and fractures. OLT have become increasingly recognized with the advancements in cartilage-sensitive diagnostic imaging modalities. Although OLT may be treated nonoperatively, a number of surgical techniques have been described for patients whom surgery is indicated. Traditionally, treatment of symptomatic OLT have included either reparative procedures, such as bone marrow stimulation(BMS), or replacement procedures, such as autologous osteochondral transplantation(AOT). Reparative procedures are generally indicated for OLT < 150 mm^2 in area. Replacement strategies are used for large lesions or after failed primary repair procedures. Although shortand medium-term results have been reported, longterm studies on OLT treatment strategies are lacking. Biological augmentation including platelet-rich plasma and concentrated bone marrow aspirate is becoming increasingly popular for the treatment of OLT to enhance the biological environment during healing. In this review, we describe the most up-to-date clinical evidence of surgical outcomes, as well as both the mechanical and biological concerns associated with BMS and AOT. In addition, we will review the recent evidence for biological adjunct therapies that aim to improve outcomes and longevity of both BMS and AOT procedures.

Establishing proof of concept:Platelet-rich plasma and bone marrow aspirate concentrate may improve cartilage repair following surgical treatment for osteochondral lesions of the talus

Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.

Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

AIM: To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1(TGF-β1) in cartilage following autologous osteochondral transplantation(AOT) in a rabbit knee cartilage defect model.METHODS: Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma(PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest(ROI)(left, right and center of the autologous grafts interfaces) were evaluated using Meta Morph. Percentage of chondrocytes positive for TGF-β1 was then assessed.RESULTS: Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs(left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point(P = 6.6 × 10^(-4), 3.1 × 10^(-4) and 7.3 × 10^(-3) for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees(36% ± 29% vs 15% ± 18%)(P = 1.8 × 10^(-6)) overall for each post-operative time point and ROI. CONCLUSION: Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo.

Clinical application of concentrated bone marrow aspirate in orthopaedics:A systematic review

AIM To examine the evidence behind the use of concentrated bone marrow aspirate(c BMA) in cartilage, bone, and tendon repair; establish proof of concept for the use of cB MA in these biologic environments; and provide the level and quality of evidence substantiating the use of cB MA in the clinical setting.METHODS We conducted a systematic review according to PRISMA guidelines. EMBASE, MEDLINE, and Web of Knowledge databases were screened for the use of cB MA in the repair of cartilage, bone, and tendon repair. We extracted data on tissue type, cB MA preparation, cB MA concentration, study methods, outcomes, and level of evidence and reported the results in tables and text.RESULTS A total of 36 studies met inclusion/exclusion criteria and were included in this review. Thirty-one of 36(86%) studies reported the method of centrifugation and preparation of cB MA with 15(42%) studies reporting either a cell concentration or an increase from baseline. Variation of c BMA application was seen amongst the studies evaluated. Twenty-one of 36(58%) were level of evidence Ⅳ, 12/36(33%) were level of evidence Ⅲ, and 3/36(8%) were level of evidence Ⅱ. Studies evaluated full thickness chondral lesions(7 studies), osteochondral lesions(10 studies), osteoarthritis(5 studies), nonunion or fracture(9 studies), or tendon injuries(5 studies). Significant clinical improvement with the presence of hyaline-like values and lower incidence of fibrocartilage on T2 mapping was found in patients receiving cB MA in the treatment of cartilaginous lesions. Bone consolidation and time to bone union was improved in patients receiving cB MA. Enhanced healingrates, improved quality of the repair surface on ultrasound and magnetic resonance imaging, and a decreased risk of re-rupture was demonstrated in patients receiving cB MA as an adjunctive treatment in tendon repair. CONCLUSION The current literature demonstrates the potential benefits of utilizing c BMA for the repair of cartilaginous lesions, bony defects, and tendon injuries in the clinical setting. This study also demonstrates discrepancies between the literature with regards to various methods of centrifugation, variable cell count concentrations, and lack of standardized outcome measures. Future studies should attempt to examine the integral factors necessary for tissue regeneration and renewal including stem cells, growth factors and a biologic scaffold.

Knee salvage procedures: The indications, techniques and outcomes of large osteochondral allografts

The overall incidence of osteochondral defect in the general population is estimated to be 15 to 30 per100000 people.These lesions can become symptomatic causing pain,swelling and decreased function of the knee,and may eventually progress to osteoarthritis.In the young and active population,partial or total knee arthroplasty(TKA)is rarely the treatment of choice due to risk of early failure.Osteochondral allograft transplantation has been demonstrated to be a safe and effective treatment of large osteochondral and chondral defects of the knee in appropriately selected patients.The treatment reduces pain,improves function and is a viable limb salvage procedure for patients,especially young and active patients for whom TKA is not recommended.Either large dowels generated with commercially available equipment or free hand shell allografts can be implanted in more posterior lesions.Current recommendations for fresh allografts stored at4C advise implantation within 21-28 d of procurement for optimum chondrocyte viability,following screening and testing protocols.Higher rates of successful allograft transplantation are observed in younger patients,unipolar lesions,normal or corrected malalignment,and defects that are treated within 12 mo of symptom onset.Patients with bipolar lesions,uncorrectable malalignment,advanced osteoarthritis,and those over40 tend to have less favourable outcomes.

Scaffolds based therapy for osteochondral lesions of the talus:A systematic review

AIM To clarify the effectiveness of scaffold-based therapy for osteochondral lesions of the talus(OLT). METHODS A systematic search of MEDLINE and EMBASE databases was performed during August 2016 and updated in January 2017. Included studies were evaluated with regard to the level of evidence(LOE) and quality of evidence(QOE) using the Modified Coleman Methodology Score. Variable reporting outcome data, clinical outcomes, and the percentage of patients who returned to sport at previous level were also evaluated. RESULTS Twenty-eight studies for a total of 897 ankles were included; 96% were either LOE Ⅲ or Ⅳ. Studies were designated as either of poor or fair quality. There were 30 treatment groups reporting six different scaffold repair techniques: 13 matrix-induced autologous chondrocyte transplantation(MACT), nine bone marrow derived cell transplantation(BMDCT), four autologous matrixinduced chondrogeneis(AMIC), and four studies of other techniques. The categories of general demographics(93%) and patient-reported outcome data(85%) were well reported. Study design(73%), imaging data(73%), clinical variables(49%), and patient history(30%) were also included. The weighted mean American Orthopaedic Foot and Ankle Society(AOFAS) score at final follow-up was: 86.7 in MACT, 88.2 in BMDCT, and 82.3 in AMIC. Eight studies reported that a weighted mean of 68.3% ofpatients returned to a previous level of sport activity. CONCLUSION Scaffold-based therapy for OLT may produce favorable clinical outcomes, but low LOE, poor QOE, and variability of the data have confounded the effectiveness of this treatment.

In vivo evaluation of additively manufacturedmulti-layered scaffold for the repair of large osteochondral defects

The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defects.However,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the tissue.In this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion techniques.The developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite system.The microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle model.The 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage formation.The histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control group.Chondrogenic genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control group.The findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.

Treatment for cartilage injuries of the knee with a new treatment algorithm

Treatment of articular cartilage injuries to the knee remains a considerable challenge today. Current procedures succeed in providing relief of symptoms, however damaged articular tissue is not replaced with new tissue of the same biomechanical properties and long-term durability as normal hyaline cartilage. Despite many arthroscopic procedures that often manage to achieve these goals, results are far from perfect and there is no agreement on which of these procedures are appropriate, particularly when full-thickness chondral defects are considered.Therefore, the search for biological solution in long-term functional healing and increasing the quality of wounded cartilage has been continuing. For achieving this goal and apply in wide defects, scaffolds are developed.The rationale of using a scaffold is to create an environment with biodegradable polymers for the in vitro growth of living cells and their subsequent implantation into the lesion area. Previously a few numbers of surgical treatment algorithm was described in reports, however none of them contained one-step or two –steps scaffolds. The ultimate aim of this article was to review various arthroscopic treatment options for different stage lesions and develop a new treatment algorithm which included the scaffolds.

Current researches on design and manufacture of biopolymer-based osteochondral biomimetic scaffolds

Currently,osteochondral(OC)tissue engineering has become a potential treatment strategy in repairing chondral lesions and early osteoarthritis due to the limited self-healing ability of cartilage.However,it is still challenging to ensure the integrity,physiological function and regeneration ability of stratified OC scaffolds in clinical application.Biomimetic OC scaffolds are attractive to overcome the above problems because of their similar biological and mechanical properties with native OC tissue.As a consequence,the researches on biomimetic design to achieve the tissue function of each layer,and additive manufacture(AM)to accomplish composition switch and ultrastructure of personalized OC scaffolds have made a remarkable progress.In this review,the design methods of biomaterial and structure as well as computer-aided design,and performance prediction of biopolymer-based OC scaffolds are presented;then,the characteristics and limitations of AM technologies and the integrated manufacture schemes in OC tissue engineering are summarized;finally,the novel biomaterials and techniques and the inevitable trends of multifunctional bio-manufacturing system are discussed for further optimizing production of tissue engineering OC scaffolds.