Treatment Of Osteochondral Defects Research Articles

Comparison of autologous matrix-induced chondrogenesis and mosaicplasty in the treatment of osteochondral defects of the talus

Comparison of autologous matrix-induced chondrogenesis and mosaicplasty in the treatment of osteochondral defects of the talus

Mesenchymal stromal cells and platelet-riach fibrin membrane for the treatment of osteochondral defect in the rabbit

Cartilage has limited self-repair ability due to its complex structure and chondrocytes' relatively low metabolic activities. Functional repair of articular cartilage defects is a significant challenge for cartilage tissue engineering. Mesenchymal stromal cells (MSC) and platelet-rich fibrin membrane (PRFM) in repairing damaged articular cartilage in rabbit. They were subjected to osteochondral lesion and randomly into five groups: Group A, evaluated immediately after injury; Group B, natural evolution the injury; Group C, MSC; Group D, PRFM and Group E, MSC+ PRFM. Animals in Group A were euthanized after removing the cartilaginous flap, while animals in Groups B, C, D, and E were euthanized 60 days. The regeneration of the lesion was evaluated by analyzing its residual extension, as well as the density of chondrocytes and chondroblasts in the regenerated tissue adjacent to the lesion. Results, the Group E (MSC + PRFM) showed a greater reduction in the lesion size and a greater density of chondrocytes and chondroblasts in the regenerated and adjacent tissue compared to the other groups. Our results indicate that the combination of MSC and PRFM can successfully resurface the defect with cartilage and restore the subchondral bone in the specie studied, being effective in reducing hyaline cartilage defects; however, the combination of MSC and PRFM products might be more or less appropriate for treating different types of tissues and pathologies. The clinical efficacy of PRP remains under debate. Therefore, further research is needed at both the basic science and clinical levels.

Enhancement of hyaline cartilage and subchondral bone regeneration in a rat osteochondral defect model through focused extracorporeal shockwave therapy.

To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm2, 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens. In the histopathological analysis, the macro-morphological grading scale showed a significant increase, while the histological score and cartilage repair scale of ESWT exhibited a significant decrease compared to OCD at the 8- and 12-week timepoints. At the 12-week follow-up, ESWT exhibited a significant improvement in the volume of damaged bone compared to OCD. Furthermore, immunohistochemistry analysis revealed a significant decrease in type I collagen and a significant increase in type II collagen within the newly formed hyaline cartilage following ESWT, compared to OCD. Finally, SRY-box transcription factor 9 (SOX9), aggrecan, and TGF-β, BMP-2, -3, -4, -5, and -7 were significantly higher in ESWT than in OCD at 12 weeks. ESWT promoted the effect of TGF-β/BMPs, thereby modulating the production of extracellular matrix proteins and transcription factor involved in the regeneration of articular cartilage and subchondral bone in an OCD rat model.

Black bioceramic scaffolds with micro/nano surface structure inducing mild hyperthermal environment for regenerating osteochondral defects

The treatment of osteochondral defects remains a huge challenge in clinic. The thermotherapy in traditional Chinese medicine is widely used in treating joint disease because the mild heat stimulation can promote the nutrient circulation. Inspired by the function of thermotherapy, we design a new thermotherapy strategy by using black bioceramic scaffolds to build local mild hyperthermal environment for treating osteochondral defects. Herein, black akermanite (B-AKT) bioceramic scaffolds with micro/nano surface structure and excellent photothermal conversion property are successfully fabricated. The temperature of scaffolds can be precisely controlled by near infrared (NIR) irradiation to construct a mild hyperthermal environment (～41°C). The micro/nanostructure on the scaffolds surface well promoted the cell adhesion and nutrition absorption by activating integrins and focal adhesion kinase (FAK). Meanwhile, the mild hyperthermal environment constructed by B-AKT scaffolds can simultaneously induce the chondrogenesis and osteogenesis both in vitro and in vivo by activating the expression of cellular heat shock proteins (HSPs) and corresponding signaling pathways. Furthermore, in rabbit osteochondral defects, mild hyperthermal environment induced by B-AKT scaffolds exhibits stimulatory effects on the integrated regeneration of cartilage and bone. This study proposes a novel therapy strategy of constructing local mild hyperthermal environment by black bioceramic scaffolds to treat osteochondral defects and other joint diseases.

Autologous bone grafting in combination with autologous chondrocyte implantation yields favourable outcomes in the treatment of osteochondral defects of the knee: A systematic literature review.

This study addresses the gap in the current literature by evaluating the combined treatment of autologous bone grafting and autologous chondrocyte implantation (ABCI) for osteochondral defects of the knee. It aims to evaluate clinical outcomes against methodological quality and to summarize histological results and surgical techniques. A thorough search was conducted across Pubmed, Cochrane and Embase databases. Studies reporting clinical outcomes of ABCI for osteochondral defects of the knee were included. Patient-reported outcome measures (PROMs), failure rates, methodological quality and potential conflicts of interest were evaluated. Histological results and surgical techniques were summarized. Eighteen studies with 344 analyzed patients met the eligibility criteria for inclusion. All studies showed a significant improvement (p < 0.05) across different PROMs (subjective International Knee Documentation Committee score, Cincinnati Knee Rating System, Visual Analogue Scale, Lysholm Score, Tegner Activity Scale, Knee injury and Osteoarthritis Outcome Score and Knee Society Score) compared to the preoperative status. Failure rates ranged from 0% to 17.6%, with a mean follow-up of 73.2 months (range: 9.0-143.6 months). Methodological quality was low to medium, including only one comparative study. Six studies reviewed reported a potential conflict of interest. The histological assessment showed effective bonding between autologous chondrocytesand bone graft. A large degree of variability was observed in the operative technique used. The current literature suggests that ABCI yields good clinical outcomes at mid- to long-term follow-up with favourable histological results for osteochondral defects of the knee. However, future research should focus on high-quality comparative studies to better guide treatment choices. Introducing ABCI as the standard abbreviation may enhance clarity in future research. Level IV.

Clinical Applicability of Autologous Chondrocyte Implantation for the Treatment of Osteochondral Defects: A Meta-analysis.

Osteoarthritis and other joint disorders are the leading cause of disability in the elderly and the treatment of joint lesions is challenging. Autologous chondrocyte implantation (ACI) has been reported with variable effects for the treatment of osteochondral and other joint lesions. In this study, we performed a meta-analysis of the recent literature to determine the clinical applicability of ACI for osteochondral defects. A meta-analysis was performed on the recent literature showing the effects of ACI on osteochondral defects. The PUBMED, ScienceDirect and Google Scholar databases were used to identify eligible studies from Jan 2010 to Sep 2022. Both fixed and random models of meta-analysis were applied with all reported scoring systems to quantify the effectiveness of ACI on osteochondral defects. The pool data of 965 patients as a case series after ACI from a fixed model showed a significant improvement in the osteochondral defects (odds ratio = 8.75, 95%CI = 7.127 to 10.743, p = 0.000). These results were further verified by a random model of meta-analysis. The data also showed a substantial heterogeneity among the studies used in the meta-analysis (Q-value = 160.41, I-squared = 87.53, p = 0.000). Furthermore, this meta-analysis also compared different ACI procedures with different scoring systems but the overall outcome remains the same as ACI was found to be useful for the healing of the osteochondral defects. This meta-analysis of 965 case series revealed that the ACI markedly improved the damage osteochondral defects scores but the optimal treatment is still controversial, therefore further studies are needed to validate these findings in a clinical setting.

Talus Osteochondral Defect Treatment With Biological Scaffold.

Talus Osteochondral defects (OCDs) are challenging and there is no consensus in literature regarding which is the best method of treatment. New techniques coming from regenerative medicine are being considered good alternatives of treatment and are being used exponentially in orthopaedic surgery. Platelet-rich fibrin (PRF) is the second generation of platelet concentrates. It has a convenient method of acquisition and can be used to create a biological scaffold which is able to seal up cavitary lesions. In this article, the authors describe a talus OCD treated with a biological scaffold, reporting the technique details and its results clinical and radiological results. The case report objective is to portray the use of this kind of biological material, its advantages, and limitations.Level of Evidence: Level 5.

A comparative analysis of 3D bioprinted gelatin-hyaluronic acid-alginate scaffold and microfracture for the management of osteochondral defects in the rabbit knee joint.

This study aims to compare the radiological, biomechanical, and histopathological results of microfracture treatment and osteochondral damage repair treatment with a new scaffold product produced by the three-dimensional (3D) bioprinting method containing gelatin-hyaluronic acid-alginate in rabbits with osteochondral damage. A new 3D bioprinted scaffold consisting of gelatin, hyaluronic acid, and alginate designed by us was implanted into the osteochondral defect created in the femoral trochlea of 10 rabbits. By randomization, it was determined which side of 10 rabbits would be repaired with a 3D bioprinted scaffold, and microfracture treatment was applied to the other knees of the rabbits. After six months of follow-up, the rabbits were sacrificed. The results of both treatment groups were compared radiologically, biomechanically, and histopathologically. None of the rabbits experienced any complications. The magnetic resonance imaging evaluation showed that all osteochondral defect areas were integrated with healthy cartilage in both groups. There was no significant difference between the groups in the biomechanical load test (p=0.579). No statistically significant difference was detected in the histological examination using the modified Wakitani scores (p=0.731). Our study results showed that 3D bioprinted scaffolds exhibited comparable radiological, biomechanical, and histological properties to the conventional microfracture technique for osteochondral defect treatment.

Subchondral Bone Alignment in Osteochondral Allograft Transplants for Large Oval Defects of the Medial Femoral Condyle: Comparison of Lateral versus Medial Femoral Condyle Donors.

Supply-demand mismatch of medial femoral condyle (MFC) osteochondral allografts (OCAs) remains a rate-limiting factor in the treatment of osteochondral defects of the femoral condyle. Surface contour mapping was used to determine whether a contralateral lateral femoral condyle (LFC) versus ipsilateral MFC OCA differs in the alignment of donor:native subchondral bone for large osteochondral defects of the MFC. Thirty fresh-frozen human femoral condyles were matched by tibial width into 10 groups of 3 condyles (MFC recipient, MFC donor, and LFC donor) each for 3 cartilage surgeons (90 condyles). The recipient MFC was imaged using nano-computed tomography scan. Donor oval grafts were harvested from each matched condyle and transplanted into a 17 mm × 36 mm defect created in the recipient condyle. Following the first transplant, the recipient condyle was imaged and superimposed on the native condyle nano-CT scan. The donor plug was removed and the process repeated for the other donor. Surface height deviation and circumferential step-off height deviation were compared between native and donor subchondral bone surfaces for each transplant. There was no statistically significant difference in mean subchondral bone surface deviation (LFC = 0.87 mm, MFC = 0.76 mm, P = 0.07) nor circumferential step-off height (LFC = 0.93 mm, MFC = 0.85 mm, P = 0.09) between the LFC and MFC plugs. There were no significant differences in outcomes between surgeons. There were no significant differences in subchondral bone circumferential step-off or surface deviation between ipsilateral MFC and contralateral LFC oval-shaped OCAs for 17 mm × 36 mm defects of the MFC.

Comparison of the ability of exosomes and ectosomes derived from adipose-derived stromal cells to promote cartilage regeneration in a rat osteochondral defect model

BackgroundExtracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) offer promising prospects for stimulating cartilage regeneration. The different formation mechanisms suggest that exosomes and ectosomes possess different biological functions. However, little attention has been paid to the differential effects of EV subsets on cartilage regeneration.MethodsOur study compared the effects of the two EVs isolated from adipose-derived MSCs (ASCs) on chondrocytes and bone marrow–derived MSCs (BMSCs) in vitro. Additionally, we loaded the two EVs into type I collagen hydrogels to optimize their application for the treatment of osteochondral defects in vivo.ResultsIn vitro experiments demonstrate that ASC-derived exosomes (ASC-Exos) significantly promoted the proliferation and migration of both cells more effectively than ASC-derived ectosomes (ASC-Ectos). Furthermore, ASC-Exos facilitated a stronger differentiation of BMSCs into chondrogenic cells than ASC-Ectos, but both inhibited chondrocyte apoptosis to a similar extent. In the osteochondral defect model of rats, ASC-Exos promoted cartilage regeneration in situ better than ASC-Ectos. At 8 weeks, the hydrogel containing exosomes group (Gel + Exo group) had higher macroscopic and histological scores, a higher value of trabecular bone volume fraction (BV/TV), a lower value of trabecular thickness (Tb.Sp), and a better remodeling of extracellular matrix than the hydrogel containing ectosomes group (Gel + Ecto group). At 4 and 8 weeks, the expression of CD206 and Arginase-1 in the Gel + Exo group was significantly higher than that in the Gel + Ecto group.ConclusionOur findings indicate that administering ASC-Exos may be a more effective EV strategy for cartilage regeneration than the administration of ASC-Ectos.

MULTILAYER DUAL-POROSITY 3D-PRINTED SCAFFOLDS TO RECREATE THE ANISOTROPIC MICROENVIRONMENT OF THE CARTILAGE

Articular cartilage is a multi-zonal tissue that coats the epiphysis of long bones and avoids its wear during motion. An unusual friction could micro-fracture this connective membrane and progress into an osteochondral defect (OD), where the affected cartilage suffers inflammation, fibrillation, and forfeiture of its anisotropic structure.Clinical treatment for ODs has been focused on micro-fracture techniques, where the defect area is removed and small incisions are performed in the subchondral bone, which allows the exudation of mesenchymal stem cells (hMSCs) to the abraded zone. However, hMSCs represent less than 0.01% of the total cell population and are not able to self-organise coherently, so the treatments fail in the long term. To select, support and steer hMSCs from the bone marrow into a specific differentiation stage, and recreate the cartilage anisotropic microenvironment, multilayer dual-porosity 3D-printed scaffolds were developed.Dual-porosity scaffolds were printed using prepared inks, containing specific ratios of poly-(d,l)lactide-co-caprolactone copolymer and gelatine microspheres of different diameters, which acted as sacrificial micro-pore templates and were leached after printing. The cell adhesion capability was investigated showing an increased cell number in dual-porosity scaffolds as compared to non-porous ones. To mimic the stiffness of the three cartilage zones, several patterns were designed, printed, and checked by dynamic-mechanical analysis under compression at 37 ºC. Three patterns with specific formulations were chosen as candidates to recreate the mechanical properties of the cartilage layers. Differentiation studies in the selected scaffolds showed the formation of mature cartilage by gene expression, protein deposition and biomolecular analysis. Given the obtained results, designed scaffolds were able to guide hMSC behaviour.In conclusion, biocompatible, multilayer and dual-porosity scaffolds with cell entrapment capability were manufactured. These anisotropic scaffolds were able to recreate the physical microenvironment of the natural cartilage, which in turn stimulated cell differentiation and the formation of mature cartilage.Acknowledgments: This work was supported by the EMAKIKER grant.

Photo-crosslinked integrated triphasic scaffolds with gradient composition and strength for osteochondral regeneration.

Owing to the avascular and aneural nature of cartilage tissue and the complex, multilayered structure of osteochondral units, the repair of osteochondral defects poses significant challenges. Traditional monophasic scaffolds have difficulty meeting the repair requirements of both cartilage and bone tissues, whereas multiphasic scaffolds face the issue of interfacial integration. In this study, a triphasic methylpropenylated gelatin (GELMA) hydrogel scaffold was employed to repair osteochondral defects, in which three layers of hydrogel were covalently bonded through a sequential curing process. The upper layer of the scaffold was covalently bonded with chondroitin sulfate, promoting chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The middle and lower layers of the hydrogel introduced a gradient content of hydroxyapatite, forming a scaffold with gradient mechanical strength and effectively enhancing its angiogenic and osteogenic induction capabilities. Finally, the triphasic integrated scaffold cartilage and bone repair performance was evaluated using a rabbit knee joint defect model. The results demonstrated that the scaffold facilitated accelerated regeneration of osteochondral defects, thus providing a novel strategy for the treatment of osteochondral defects.

Bioinspired Hard–Soft Composite Scaffold with Excellent Lubrication and Osteogenic Properties for the Treatment of Osteochondral Defect

AbstractNatural articular cartilage is a typical self‐healing and superlubrication system capable of maintaining extremely low friction under physiological loadings. Cartilage wear and accidental trauma can cause irreversible defects to cartilage and subchondral bone with a significant decrease in intra‐articular lubrication, leading to the development of severe osteoarthritis and osteochondral defect. To address the important clinical problem of osteochondral defect, a bioinspired hard–soft (PEEK‐lubrication hydrogel) composite scaffold is designed and developed. The polymerization of polyethylene glycol diacrylamide (PEGDAA) and 2‐methacryloyloxyethyl phosphorylcholine (MPC) on polyetheretherketone (PEEK) substrate is achieved by UV initiation to form a strong interfacial bonding, and nano‐hydroxyapatite is deposited on porous PEEK substrate via polydopamine coating to improve osteogenic capability. Accordingly, the composite scaffold is successfully developed with lubrication and osteogenic activity. The tribological tests show that the lubrication performance of the composite scaffold is based on the hydration lubrication mechanism of the upper hydrogel layer, and the in vitro and in vivo experiments demonstrate that the composite scaffold is endowed with excellent biocompatibility and bioactivity. In conclusion, the bioinspired strategy for preparing a hard–soft composite scaffold shows a promising way in the treatment of osteochondral defect and provided a guideline for designing functional PEEK‐based biomaterials in tissue engineering scaffolds.

Tetracalcium Phosphate Biocement Hardened with a Mixture of Phytic Acid–Phytase in the Healing Process of Osteochondral Defects in Sheep

Hyaline articular cartilage has unique physiological, biological, and biomechanical properties with very limited self-healing ability, which makes the process of cartilage regeneration extremely difficult. Therefore, research is currently focused on finding new and potentially better treatment options. The main objective of this in vivo study was to evaluate a novel biocement CX consisting of tetracalcium phosphate–monetit biocement hardened with a phytic acid–phytase mixture for the regeneration of osteochondral defects in sheep. The results were compared with tetracalcium phosphate–monetit biocement with classic fast-setting cement systems and untreated defects. After 6 months, the animals were sacrificed, and the samples were evaluated using macroscopic and histologic methods as well as X-ray, CT, and MR-imaging techniques. In contrast to the formation of fibrous or fibrocartilaginous tissue on the untreated side, treatment with biocements resulted in the formation of tissue with a dominant hyaline cartilage structure, although fine fibres were present (p &lt; 0.001). There were no signs of pathomorphological changes or inflammation. Continuous formation of subchondral bone and hyaline cartilage layers was present even though residual biocement was observed in the trabecular bone. We consider biocement CX to be highly biocompatible and suitable for the treatment of osteochondral defects.

Use of polyglycolic acid-hyaluronic acid/β-tricalcium phosphate scaffold with or without mesenchymal stem cells found ineffective in treating osteochondral lesions in rabbit knees.

In this experimental animal study, a novel bilayered scaffold used in the treatment of osteochondral defects in rabbit knees was evaluated. This novel scaffold's upper (cartilage) layer consists of polyglycolic acid and hyaluronic acid, and the lower (bone) layer consists of β-tricalcium phosphate. The purpose of this study was to evaluate the efficacy of this novel scaffold, combined with or without mesenchymal stem cells (MSCs), in the treatment of osteochondral defects in rabbit knees. Osteochondral defects were created in the left femoral trochlea of 30 rabbits. In group A, defects were treated with scaffold combined with MSCs; in group B, defects were treated with cell-free scaffolds; and group C was a control group with defects left untreated. In the 12th week, animals were sacrificed for macroscopic evaluation. The mean International Cartilage Repair Society (ICRS) macroscopic scores were 4.95 for group A, 6.16 for group B, and 8.25 for group C. The mean Oswestry Arthroscopic Scores (OAS) were 1.65 for group A, 3.39 for group B, and 6.05 for group C. The macroscopic scores were significantly higher in group C than group A for ICRS scores and group A and group B for OAS (P < .001, P < .000, P < .022). In essence, our findings indicate that the newly developed osteochondral scaffold, when tested in a rabbit model, is not as effective as expected in repairing full-thickness osteochondral defects, with or without the supplementation of MSCs. Further investigation is required to enhance the effectiveness of this novel combination.

Reinforcing Tissue‐Engineered Cartilage: Nanofibrillated Cellulose Enhances Mechanical Properties of Alginate Dialdehyde–Gelatin Hydrogel

Cartilage tissue engineering offers a promising option for treating osteochondral defects. Alginate dialdehyde–gelatin (ADA–GEL) hydrogel has been explored as promising material for soft tissue scaffolds; however, its low stiffness has posed a constraint to load bearing applications. Herein, this limitation is addressed by introducing nanofibrillated cellulose (NFC) into the ADA–GEL matrix. The effect of NFC on the physicochemical properties of hydrogels is evaluated. Fourier transform infrared spectra demonstrate no chemical interaction between NFC and ADA–GEL, while scanning electron microscopy pictures reveal NFC fibers embedded in the hydrogel matrix, thus confirming the fiber‐reinforced composite hypothesis. NFC‐reinforced ADA–GEL (AG‐N) composite hydrogels exhibit increased stiffness, with a maximum compressive effective modulus of 19.6 ± 3.0 kPa at 25% w/w NFC content. ATDC5 cell viability and proliferation as well as chondrogenic differentiation are assessed using immunohistochemical staining for sulfated glycosaminoglycans and collagen type II. A possible application of AG‐N hydrogels as an osteochondral plug is also proposed, with polyetheretherketone as the subchondral bone anchor part. The mechanical properties of the resulting osteochondral device highlight its potential as a promising biomaterial for treatment of osteochondral defects. These findings provide valuable insights into the development of AG‐N hydrogels for load‐bearing tissue engineering applications.

Osteochondral Repair with Autologous Cartilage Transplantation with or without Bone Grafting: A Short Pilot Study in Mini-Pigs.

Treatment strategies for osteochondral defects, for which particulated autologous cartilage transplantation (PACT) is an emerging treatment strategy, aim to restore the structure and function of the hyaline cartilage. Herein, we compared the efficacy of PACT with control or human transforming growth factor-β (rhTGF-β), and clarified the necessity of bone graft (BG) with PACT to treat shallow osteochondral defects in a porcine model. Two skeletally mature male micropigs received 4 osteochondral defects in each knee. The 16 defects were randomized to (1) empty control, (2) PACT, (3) PACT with BG, or (4) rhTGF-β. Animals were euthanized after 2 months and histomorphometry, immunofluorescence analysis, semiquantitative evaluation (O'Driscoll score), and magnetic resonance observation of cartilage repair tissue (MOCART) score were performed. Hyaline cartilages, glycosaminoglycan synthesis, and collagen type II staining were more abundant in the PACT than in the control and rhTGF-β groups. The O'Driscoll score was significantly different between groups (P < 0.001), with both PACT groups showing superiority (P = 0.002). PACT had the highest score (P = 0.002), with improved restoration of subchondral bone compared with PACT with BG. The MOCART score showed significant differences between groups (P = 0.021); MOCART and O'Driscoll scores showed high correlation (r = 0.847, P < 0.001). Treatment of osteochondral defects with PACT improved tissue quality compared with that with control or rhTGF-β in a porcine model. BG, in addition to PACT, may be unnecessary for shallow osteochondral defects. Clinical Relevance. BG may not be necessary while performing PACT.

Dual-tissue transplantation versus osteochondral autograft transplantation in the treatment of osteochondral defects: a porcine model study

BackgroundOsteochondral injury is a common sports injury, and hyaline cartilage does not regenerate spontaneously when injured. However, there is currently no gold standard for treating osteochondral defects. Osteochondral autograft transplantation (OAT) is widely used in clinical practice and is best used to treat small osteochondral lesions in the knee that are < 2 cm2 in size. Autologous dual-tissue transplantation (ADTT) is a promising method with wider indications for osteochondral injuries; however, ADTT has not been evaluated in many studies. This study aimed to compare the radiographic and histological results of ADTT and OAT for treating osteochondral defects in a porcine model.MethodsOsteochondral defects were made in the bilateral medial condyles of the knees of 12 Dian-nan small-ear pigs. The 24 knees were divided into the ADTT group (n = 8), OAT group (n = 8), and empty control group (n = 8). At 2 and 4 months postoperatively, the knees underwent gross evaluation based on the International Cartilage Repair Society (ICRS) score, radiographic assessment based on CT findings and the magnetic resonance observation of cartilage repair tissue (MOCART) score, and histological evaluation based on the O'Driscoll histological score of the repair tissue.ResultsAt 2 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score were significantly better in the OAT group than the ADTT group (all P < 0.05). At 4 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score tended to be better in the OAT group than the ADTT group, but these differences did not reach statistical significance (all P > 0.05).ConclusionsIn a porcine model, ADTT and OAT are both effective treatments for osteochondral defects in weight bearing areas. ADTT may be useful as an alternative procedure to OAT for treating osteochondral defects.

A Biphasic Hydrogel with Self-Healing Properties and a Continuous Layer Structure for Potential Application in Osteochondral Defect Repair.

The treatment of osteochondral defects remains challenging due to the limited healing capacity of cartilage and the poor results of traditional methods. Inspired by the structure of natural articular cartilage, we have fabricated a biphasic osteochondral hydrogel scaffold using a Schiff base reaction and a free radical polymerization reaction. Carboxymethyl chitosan (CMCS), oxidized sodium alginate (OSA), and polyacrylamide (PAM) formed a hydrogel (COP) as the cartilage layer, while hydroxyapatite (HAp) was incorporated into the COP hydrogel to obtain a hydrogel (COPH) as an subchondral bone layer. At the same time, hydroxyapatite (HAp) was incorporated into the COP hydrogel to obtain a hydrogel (COPH) as an osteochondral sublayer, combining the two to obtain an integrated scaffold for osteochondral tissue engineering. Interlayer interpenetration through the continuity of the hydrogel substrate and good self-healing properties due to the dynamic imine bonding of the hydrogel resulted in enhanced interlayer bond strength. In addition, in vitro experiments have shown that the hydrogel exhibits good biocompatibility. It shows great potential for osteochondral tissue engineering applications.

Harnessing Biofabrication Strategies to Re-Surface Osteochondral Defects: Repair, Enhance, and Regenerate.

Osteochondral tissue (OC) is a complex and multiphasic system comprising cartilage and subchondral bone. The discrete OC architecture is layered with specific zones characterized by different compositions, morphology, collagen orientation, and chondrocyte phenotypes. To date, the treatment of osteochondral defects (OCD) remains a major clinical challenge due to the low self-regenerative capacity of damaged skeletal tissue, as well as the critical lack of functional tissue substitutes. Current clinical approaches fail to fully regenerate damaged OC recapitulating the zonal structure while granting long-term stability. Thus, the development of new biomimetic treatment strategies for the functional repair of OCDs is urgently needed. Here, we review recent developments in the preclinical investigation of novel functional approaches for the resurfacing of skeletal defects. The most recent studies on preclinical augmentation of OCDs and highlights on novel studies for the in vivo replacement of diseased cartilage are presented.