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Type I collagen (Col I) and hyaluronic acid (HA), derived from the extracellular matrix (ECM), have found widespread application in cartilage tissue engineering. Nevertheless, the potential of cell-free collagen-based scaffolds to induce in situ hyaline cartilage regeneration and the related mechanisms remain undisclosed. Here, we chose Col I and HA to construct Col I hydrogel and Col I-HA composite hydrogel with similar mechanical properties, denoted as Col and ColHA, respectively. Their potential to induce cartilage regeneration was investigated. The results revealed that collagen-based hydrogels could regenerate hyaline cartilage without any additional cells or growth factors. Notably, ColHA hydrogel stood out in this regard. It elicited a moderate activation, recruitment, and reprogramming of macrophages, thus efficiently mitigating local inflammation. Additionally, ColHA hydrogel enhanced stem cell recruitment, facilitated their chondrogenic differentiation, and inhibited chondrocyte fibrosis, hypertrophy, and catabolism, thereby preserving cartilage homeostasis. This study augments our comprehension of cartilage tissue induction theory by enriching immune-related mechanisms, offering innovative prospects for the design of cartilage defect repair scaffolds. The limited self-regeneration ability and post-injury inflammation pose significant challenges to articular cartilage repair. Type I collagen (Col I) and hyaluronic acid (HA) are extensively used in cartilage tissue engineering. However, their specific roles in cartilage regeneration remain poorly understood. This study aimed to elucidate the functions of Col I and Col I-HA composite hydrogels (ColHA) in orchestrating inflammatory responses and promoting cartilage regeneration. ColHA effectively activated and recruited macrophages, reprogramming them from an M1 to an M2 phenotype, thus alleviating local inflammation. Additionally, ColHA facilitated stem cell homing, induced chondrogenesis, and concurrently inhibited fibrosis, hypertrophy, and catabolism, collectively contributing to the maintenance of cartilage homeostasis. These findings underscore the clinical potential of ColHA for repairing cartilage defects. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Hesperetin, a flavonoid derived from citrus fruits, exhibits potent antioxidant and anti-inflammatory activities and has been implicated in cartilage protection. However, its effectiveness against T-2 toxin-induced knee cartilage damage remains unclear. Methods: In this study, high-throughput sequencing analysis was employed to identify the key signaling pathways involved in T-2 toxin-induced articular cartilage damage in rats. Animal models were divided into the following groups: control, low-dose T-2 toxin, high-dose T-2 toxin, T-2 toxin + hesperetin, hesperetin, and vehicle. Pathological staining and immunohistochemistry were used to assess pathological changes, as well as the expression levels of the cartilage matrix-related proteins MMP13 and collagen II, along with the activation of the p38 MAPK signaling pathway. Additionally, primary rat chondrocytes were cultured to establish an in vitro model for investigating the underlying mechanism. Results: High-throughput sequencing analysis revealed the involvement of the MAPK signaling pathway in T-2 toxin-induced articular cartilage damage in rats. Hesperetin intervention in T-2 toxin-exposed rats attenuated pathological cartilage damage. Immunohistochemistry results demonstrated a significant reduction in collagen II protein expression in the high-dose T-2 toxin group (p < 0.01), accompanied by a significant increase in MMP13 protein expression (p < 0.01). In both the articular cartilage and the epiphyseal plate, the T-2 toxin + hesperetin group exhibited significantly higher collagen II protein expression than the high-dose T-2 toxin group (p < 0.05), along with significantly lower MMP13 protein expression (p < 0.05). Hesperetin inhibited the over-activation of the p38/MEF2C signaling axis induced by T-2 toxin in primary rat chondrocytes. Compared to the T-2 toxin group, the T-2 toxin + hesperetin group showed significantly reduced phosphorylation levels of p38 and protein expression levels of MEF2C (p < 0.001 or p < 0.05). Moreover, the T-2 toxin + hesperetin group exhibited a significant decrease in MMP13 protein expression (p < 0.05) and a significant increase in collagen II protein expression (p < 0.01) compared to the T-2 toxin group. Conclusions: T-2 toxin activates the p38 MAPK signaling pathway, causing knee cartilage damage in rats. Treatment with hesperetin inhibits the p38/MEF2C signaling axis, regulates collagen II and MMP13 protein expression, and reduces cartilage injury significantly. [ABSTRACT FROM AUTHOR]

EphrinB2, a member of the Ephrin family, has been linked to several orthopaedic conditions. Nevertheless, the correlation between ephrinB2 and post‐traumatic arthritis (PTOA) remains unclear. Human PTOA cartilage from human and mouse knee joints was systematically analysed to investigate the relationship between EphrinB2 and PTOA using SO‐FG and toluidine blue staining, micro‐CT, histomorphometry, immunohistochemistry, immunofluorescence, lentiviral articular injection and in situ end labeling (TUNEL) assays. EphrinB2 expression was significantly downregulated in PTOA chondrocytes. Blocking EphrinB2 increased the breakdown of cartilage matrix in mice with PTOA via reducing the process of chondrocyte autophagy. The presence of severe cartilage damage was evident, as indicated by a considerable decrease in both cartilage thickness and area, accompanied by an increase in chondrocyte death. Altogether, EphrinB2 is required for the maintenance of cartilage homeostasis in post‐traumatic arthritis, and EphrinB2 ablation is associated with accelerated chondrocyte matrix degeneration, finally causing damage to the articular cartilage. [ABSTRACT FROM AUTHOR]

Articular cartilage damage and wear can result in cartilage degeneration, ultimately culminating in osteoarthritis. Current surgical interventions offer limited capacity for cartilage tissue regeneration and offer only temporary alleviation of symptoms. Tissue engineering strategies are increasingly recognized as promising modalities for cartilage restoration. Currently, various biological scaffolds utilizing tissue engineering materials are extensively employed in both fundamental and clinical investigations of cartilage repair. In order to optimize the cartilage repair ability of tissue engineering scaffolds, researchers not only optimize the structure and properties of scaffolds from the perspective of materials science and manufacturing technology to enhance their histocompatibility, but also adopt strategies such as loading cells, cytokines, and drugs to promote cartilage formation. This review provides an overview of contemporary tissue engineering strategies employed in cartilage repair, as well as a synthesis of existing preclinical and clinical research. Furthermore, the obstacles faced in the translation of tissue engineering strategies to clinical practice are discussed, offering valuable guidance for researchers seeking to address these challenges. [ABSTRACT FROM AUTHOR]

The repair and regeneration of cartilage is a challenge for scientists and clinical surgery. Achieving cell adhesion and regeneration, anti‐inflammatory, lubrication, targeted drug delivery and controlled release simultaneously in cartilage treatment are the goals of researchers. Polymer composites and hybrids have the potential to realize above functions in cartilage tissue engineering. This review refers to cartilage injuries, current clinical techniques, and their benefits and limitations, focusing on the most relevant and state of art of advanced polymers for cartilage tissue engineering. The frontier applications of multifunctional polymer composites and hybrids in cartilage tissue engineering are discussed in depth, including polymer scaffold, polymer bio‐lubricant, and zwitterionic polymer for drug delivery and sustained drug release. A summary of comprehensive properties of polymers such as processability, mechanical properties, biocompatibility, biodegradability, hydrophilicity, cytotoxicity, etc., and their mechanisms are analyzed. Furthermore, some key challenges and outstanding concerns on polymer‐based materials for cartilage tissue engineering are presented followed by future perspectives. Highlights: The state of art of advanced polymers for cartilage tissue engineering.The advanced bionic property and mechanism of polymer composites and hybrids.Polymers for scaffold, biolubricant, drug delivery, sustained drug release.Future perspectives on polymer composites, hybrids‐based cartilage materials. [ABSTRACT FROM AUTHOR]

Objectives: In-depth understanding of osteonecrosis of femoral head (ONFH) has revealed that degeneration of the hip cartilage plays a crucial role in ONFH progression. However, the underlying molecular mechanisms and susceptibility to environmental factors in hip cartilage that contribute to ONFH progression remain elusive. Methods: We conducted a multiomics study and chemical−gene interaction analysis of hip cartilage in ONFH. The differentially expressed genes (DEGs) involved in ONFH progression were identified in paired hip cartilage samples from 36 patients by combining genome-wide DNA methylation profiling, gene expression profiling, and quantitative proteomics. Gene functional enrichment and pathway analyses were performed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Functional links between proteins were discovered through protein−protein interaction (PPI) networks. The ONFH-associated chemicals were identified by integrating the DEGs with the chemical−gene interaction sets in the Comparative Toxicogenomics Database (CTD). Finally, the DEGs, including MMP13 and CHI3L1, were validated via quantitative real-time PCR (qRT−PCR) and immunohistochemistry (IHC). Results: Twenty-two DEGs were identified across all three omics levels in ONFH cartilage, 16 of which were upregulated and six of which were downregulated. The collagen-containing extracellular matrix (ECM), ECM structural constituents, response to amino acids, the relaxin signaling pathway, and protein digestion and absorption were found to be primarily involved in cartilage degeneration in ONFH. Moreover, ten major ONFH-associated chemicals were identified, including, benzo(a)pyrene, valproic acid, and bisphenol A. Conclusion: Overall, our study identified several candidate genes, pathways, and chemicals associated with cartilage degeneration in ONFH, providing novel clues into the etiology and biological processes of ONFH progression. [ABSTRACT FROM AUTHOR]

Introduction High-rate non-penetrating blunt impacts to the thorax, such as from impacts to protective equipment, can lead to a wide range of thoracic injuries. These injuries can include rib fractures, lung contusions, and abdominal organ contusions. Ovine animals have been used to study such impacts, in a variety of ways, including in silico. To properly model these impacts in silico, it is imperative that the tissues impacted are properly characterized. The objective of this study is to characterize and validate two tissues impacted that are adjacent to the point of impact—costal cartilage and hide. Heretofore, these materials have not been characterized for use in computational models despite their nearly immediate engagement in the high-rate, non-penetrating loading environment. Materials and Methods Ovine costal cartilage and hide samples were procured from a local abattoir following USDA regulations. Costal cartilage samples were then cut into ASTM D638 Type V tensile coupons and compressive disks for testing. The cartilage tensile coupons were tested at 150 ε/s, and the compressive samples were tested at −150 ε/s. Identical coupons and disks were then simulated in LS-Dyna using a hyperelastic material model based on test data and experimental boundary conditions. Hide samples were shaved and cut into ASTM D638 Type V tensile coupons and validated in silico using identical boundary conditions and an Ogden rubber model based on test data. Results The structural responses of costal cartilage and hide are presented and exhibit typical behavior for biological specimens. The respective model fits in LS-Dyna were a hyperelastic- based "simplified rubber" for the costal cartilage and an Ogden rubber for the hide. The costal cartilage had a mean failure strain of 0.094 ± 0.040 in tension and −0.1755 ± 0.0642 in compression. The costal cartilage was also noted to have an order-of-magnitude difference in the stresses observed experimentally between the tensile and compressive experiments. Hide had a mean failure strain of 0.2358 ± 0.1362. The energies for all three simulations showed material stability. Conclusions Overall, we successfully characterized the mechanical behavior of the hide and costal cartilage in an ovine model. The data are intended for use in computational analogs of the ovine model for testing non-penetrating blunt impact in silico. To improve upon these models, rate sensitivity should be included, which will require additional mechanical testing. [ABSTRACT FROM AUTHOR]

Cartilage, a critical tissue for joint function, often degenerates due to osteoarthritis (OA), rheumatoid arthritis (RA), and trauma. Recent research underscores necroptosis, a regulated form of necrosis, as a key player in cartilage degradation. Unlike apoptosis, necroptosis triggers robust inflammatory responses, exacerbating tissue damage. Key mediators such as receptor-interacting serine/threonine-protein kinase-1 (RIPK1), receptor-interacting serine/threonine-protein kinase-3(RIPK3), and mixed lineage kinase domain-like (MLKL) are pivotal in this process. Studies reveal necroptosis contributes significantly to OA and RA pathophysiology, where elevated RIPK3 and associated proteins drive cartilage degradation. Targeting necroptotic pathways shows promise; inhibitors like Necrostatin-1 (Nec-1), GSK'872, and Necrosulfonamide (NSA) reduce necroptotic cell death, offering potential therapeutic avenues. Additionally, autophagy's role in mitigating necroptosis-induced damage highlights the need for comprehensive strategies addressing multiple pathways. Despite these insights, further research is essential to fully understand necroptosis' mechanisms and develop effective treatments. This review synthesizes current knowledge on necroptosis in cartilage degeneration, aiming to inform novel therapeutic approaches for OA, RA, and trauma. [ABSTRACT FROM AUTHOR]

Desbuquois dysplasia type 1 (DBQD1) is a recessive chondrodysplasia caused by mutations in the CANT1 gene, encoding for the Golgi Calcium-Activated Nucleotidase 1 (CANT1). The enzyme hydrolyzes UDP, the by-product of glycosyltransferase reactions, but it might play other roles in different cell types. Using a Cant1 knock-out mouse, we demonstrated that CANT1 is crucial for glycosaminoglycan (GAG) synthesis; however, its impact on the biochemical properties of cartilage proteoglycans remains unknown. Thus, in this work, we characterized decorin and aggrecan from primary chondrocyte cultures and cartilage biopsies of mutant mice at post-natal day 4 by Western blots and further investigated their distribution in the cartilage extracellular matrix (ECM) by immunohistochemistry. We demonstrated that the GAG synthesis defect caused by CANT1 impairment led to the synthesis and secretion of proteoglycans with shorter GAG chains compared with wild-type animals. However, this alteration did not result in the synthesis and secretion of decorin and aggrecan in the unglycanated form. Interestingly, the defect was not cartilage-specific since also skin decorin showed a reduced hydrodynamic size. Finally, immunohistochemical studies in epiphyseal sections of mutant mice demonstrated that the proteoglycan structural defect moderately affected decorin distribution in the ECM. [ABSTRACT FROM AUTHOR]

Nutritional epigenomics is exceptionally important because it describes the complex interactions among food compounds and epigenome modifications. Phytonutrients or bioactive compounds, which are secondary metabolites of plants, can protect against osteoarthritis by suppressing the expression of inflammatory and catabolic mediators, modulating epigenetic changes in DNA methylation, and the histone or chromatin remodelling of key inflammatory genes and noncoding RNAs. The combination of natural epigenetic modulators is crucial because of their additive and synergistic effects, safety and therapeutic efficacy, and lower adverse effects than conventional pharmacology in the treatment of osteoarthritis. In this review, we have summarized the chondroprotective properties of bioactive compounds used for the management, treatment, or prevention of osteoarthritis in both human and animal studies. However, further research is needed into bioactive compounds used as epigenetic modulators in osteoarthritis, in order to determine their potential value for future clinical applications in osteoarthritic patients as well as their relation with the genomic and nutritional environment, in order to personalize food and nutrition together with disease prevention. [ABSTRACT FROM AUTHOR]

Multiple osteochondromas (MO) is an autosomal dominant disorder and the most common genetic skeletal dysplasia, characterized by the growth of bone outgrowths capped by cartilage, called osteochondromas. Most MO cases are caused by mutations in the exostosin-1 (EXT1) and exostosin-2 (EXT2) genes. Only 5% of MO-causative variants are represented by single or multiple exon deletions; to date, no pathogenic large duplication has been described in the literature. In the present study, we describe the novel in-tandem intragenic duplication c.(1128_1202)_(1284+29_1344)dup involving exon 4 of EXT1 (NM_000127.2), detected in a three-generation family with MO. The variant has been detected by MLPA (multiplex ligation-dependent probe amplification) and then confirmed with qPCR (quantitative PCR). Our finding expands the spectrum of MO-causing variants describing a pathogenic large duplication, underlying the importance of quantitative analysis in patients with negative sequencing. [ABSTRACT FROM AUTHOR]

Ewing-like sarcomas (ELS) are round cell mesenchymal neoplasms that are highly aggressive to bone and/or soft tissue. However, they rarely occur in the nose, with no reported such cases in the medical literature to date. Here, we reported the case of a two-year-old Chinese boy who presented with a mass in the left nasal cavity. Surprisingly, the final histopathological diagnosis of the nasal mass was determined to be a subtype of ELS, BCOR -rearranged sarcoma. Therefore, we retrospectively analyzed the clinical data of this case and reviewed the relevant literature on ELS and BCOR -rearranged sarcoma. The purpose of this article is to provide new insights into the clinical characteristics of children with BCOR -rearranged Ewing-like sarcoma and to improve the understanding of this disease. [ABSTRACT FROM AUTHOR]

Recent evidence indicates that the damaged regions in osteoarthritis are accompanied by the accumulation of iron ions. Ferroptosis, as an iron‐dependent form of cell death, holds significant implications in osteoarthritis. Melatonin, a natural product with strong scavenging abilities against reactive oxygen species and lipid peroxidation, plays a crucial role in the treatment of osteoarthritis. This study aims to demonstrate the existence of ferroptosis in osteoarthritis and explore the specific mechanism of melatonin in suppressing ferroptosis and alleviating osteoarthritis. Our findings reveal that melatonin reverses inflammation‐induced oxidative stress and lipid peroxidation while promoting the expression of extracellular matrix components in chondrocytes, safeguarding the cells. Our research has revealed that NADPH oxidase 4 (NOX4) serves as a crucial molecule in the ferroptosis process of osteoarthritis. Specifically, NOX4 is located on mitochondria in chondrocytes, which can induce disorders in mitochondrial energy metabolism and dysfunction, thereby intensifying oxidative stress and lipid peroxidation. LC‐MS analysis further uncovered that GRP78 is a downstream binding protein of NOX4. NOX4 induces ferroptosis by weakening GRP78's protective effect on GPX4 and reducing its expression. Melatonin can inhibit the upregulation of NOX4 on mitochondria and mitigate mitochondrial dysfunction, effectively suppressing ferroptosis and alleviating osteoarthritis. This suggests that melatonin therapy represents a promising new approach for the treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]

Objective To investigate the efficacy of autologous costal cartilage cortex as a nasal tip support and modification graft in improving the nasal tip morphology. Methods From March 2021 to June 2022, 89 patients who underwent rhinoplasty with a focus on nasal tip shaping were enrolled. CT scans were used as an auxiliary examination, and costal cartilage was harvested. The cortical layer of the costal cartilage was shaped into "plate-like" and "cap-like" grafts to sculpt the nasal tip morphology, while expanded polytetrafluoroethylene (ePTFE) or silicone implants were used to elevate the nasal dorsum. Photometric methods were employed to obtain the patients' nasofacial parameters, which were then compared before and after surgery to observe patient satisfaction and the occurrence of complications. Results All 89 patients were followed up for 6 to 24 months, with an average of 9 months. Postoperatively, there were no intranasal occupations or graft protrusions. Patients reported no foreign body sensation in the external nasal valve upon self-examination, and the nasal tip was able to move laterally. The nasal tip exhibited distinct tip-defining points, a full lower lateral cartilage lobule, and no complications such as cartilage visibility, exposure, or infection. Two patients experienced deviation of the nasal columella and asymmetrical nostrils due to unaddressed septal deviation. Measurement results showed significant improvements in postoperative nasal length, nasal tip rotation, nasofrontal angle, and nasal tip projection, with statistically significant differences compared to preoperative values (P<0.05). Conclusion The application of autologous costal cartilage cortex as a nasal tip support and modifying graft to improve nasal tip morphology is a good surgical technique. The shaped nasal tip is soft and movable without affecting the airway, making it worthy of clinical application. [ABSTRACT FROM AUTHOR]

Objective To evaluate the clinical effect of costal cartilage sculpted polygonal nasal tip graft in rhinoplasty. Methods From June 2016 to December 2021, 368 patients with poor nasal tip shape underwent rhinoplasty with costal cartilage sculpted polygonal nasal tip graft. Postoperative complications, incision scar, nasal tip protrusion, nasal tip morphology improvement, and overall satisfaction were evaluated. Results All 368 patients were followed up for 12 to 46 months, and the nasal tip protrusion and shape of the patients improved well. Five patients showed a slight downward rotation of the nasal tip 12 to 19 months postoperation, and 4 patients showed a cartilaginous appearance of the nasal tip 12 to 16 months postoperation, which was improved after the second rhinoplasty. No flap necrosis, infection, delayed incision healing, or other complications occurred, no obvious incision scar formation and nasal tip skewed. Postoperative overall satisfaction was high, including 312 very satisfied cases, 45 satisfied cases, and 11 general cases, the satisfaction rate was 97.0%. Conclusion The application of costal cartilage sculpted polygonal nasal tip grafts in rhinoplasty has the following advantages. The graft is conformed to the anatomical and aesthetic characteristics of the nasal tip, can effectively reduce the height of the nasal tip strut, reduce the incidence of skewness, and reduce the tension of the alar cartilage and mucosa. The postoperative effect is good, the overall satisfaction of patients is high, and it is worthy of clinical popularization and application. [ABSTRACT FROM AUTHOR]

Articular cartilage receives nutrients and oxygen from the synovial fluid to maintain homeostasis. However, compared to tissues with abundant blood flow, articular cartilage is exposed to a hypoxic environment (i.e., physioxia) and has an enhanced hypoxic stress response. Hypoxia-inducible factors (HIFs) play a pivotal role in this physioxic environment. In normoxic conditions, HIFs are downregulated, whereas in physioxic conditions, they are upregulated. The HIF-α family comprises three members: HIF-1α, HIF-2α, and HIF-3α. Each member has a distinct function in articular cartilage. In osteoarthritis, which is primarily caused by degeneration of articular cartilage, HIF-1α is upregulated in chondrocytes and is believed to protect articular cartilage by acting anabolically on it. Conversely, in contrast to HIF-1α, HIF-2α exerts a catabolic influence on articular cartilage. It may therefore be possible to develop a new treatment for OA by controlling the expression of HIF-1α and HIF-2α with drugs or by altering the oxygen environment in the joints. [ABSTRACT FROM AUTHOR]

Inflammation models are widely used in the in vitro investigation of new therapeutic approaches for osteoarthritis. TNFα (tumor necrosis factor alpha) plays an important role in the inflammatory process. Current inflammation models lack uniformity and make comparisons difficult. Therefore, this study aimed to systematically investigate whether the effects of TNFα are concentration-dependent and whether chondrocyte expansion has an effect on the inflammatory model. Bovine chondrocytes were enzymatically isolated, expanded to passages 1–3, and transferred into a 3D pellet culture. Chondrocyte pellets were stimulated with recombinant bovine TNFα at different concentrations for 48 h to induce inflammation. Gene expression of anabolic (collagen 2, aggrecan, cartilage oligomeric protein (COMP)), catabolic (matrix metalloproteinases (MMP3, MMP13)), dedifferentiation (collagen 1) markers, inflammation markers (interleukin-6 (IL-6), nuclear factor kappa B (NFkB), cyclooxygenase-2 (COX), prostaglandin-E-synthase-2 (PTGES2)), and the apoptosis marker caspase 3 was determined. At the protein level, concentrations of IL-6, nitric oxide (NO), and sulfated glycosaminoglycans (GAG) were evaluated. Statistical analysis was performed using the independent t-test, and significance was defined as p < 0.05. In general, TNFα caused a decrease in anabolic markers and an increase in the expression of catabolic and inflammatory markers. There was a concentration-dependent threshold of 10 ng/mL to induce significant inflammatory effects. Most of the markers analyzed showed TNFα concentration-dependent effects (COMP, PRG4, AGN, Col1, MMP3, and NFkB). There was a statistical influence of selected gene expression markers from different passages on the TNFα chondrocyte inflammation model, including Col2, MMP13, IL-6, NFkB, COX2, and PTGES2. Considering the expression of collagen 2 and MMP3, passage 3 chondrocytes showed a higher sensitivity to TNFα stimulation compared to passages 1 and 2. On the other hand, MMP13, IL-6, NFkB, and caspase 3 gene expression were lower in P3 chondrocytes compared to the other passages. On the protein level, inflammatory effects showed a similar pattern, with cytokine effects starting at 10 ng/mL and differences between the passages. TNFα had a detrimental effect on cartilage, with a clear threshold observed at 10 ng/mL. Although TNFα effects showed concentration-dependent patterns, this was not consistent for all markers. The selected passage showed a clear influence, especially on inflammation markers. Further experiments were warranted to explore the effects of TNFα concentration and passage in long-term stimulation. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to prospectively investigate the progression of cartilage thinning in patients with symptomatic rotator cuff tears using MRI. Methods: Two hundred twenty-five consecutive patients with symptomatic rotator cuff tears visited our institute between 2009 and 2019. Of these, 28 shoulders of 27 patients (mean age, 65 years) who underwent at least two magnetic resonance imaging (MRI) examinations were prospectively enrolled. They all received conservative treatment. The mean follow-up was 67 months. Changes in cartilage thickness and the combined cartilage and subchondral bone thickness at the initial and final MRI were measured using a RadiAnt DICOM-viewer (Medixant, Poznan, Poland). The cartilage thickness of the humeral head was measured in the oblique coronal and sagittal images. The glenoid cartilage was measured in the axial and oblique coronal images. Results: At an average period of 5 years, 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head. The glenoid showed cartilage thinning in only one shoulder (4%). In the humeral head, progressive cartilage thinning was seen mainly in the anterior and posterior parts of the humeral head in the sagittal plane. In the glenoid, progressive cartilage thinning was seen on the entire surface except the posterior area. There was no significant difference in cartilage thickness between the first and final follow-ups for both the humeral head and the glenoid. Conclusions: A total of 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head, which was mainly observed in the anterior and posterior areas of the humeral head. [ABSTRACT FROM AUTHOR]

Purpose: To describe the clinical outcomes of patients who underwent surgical repair through an anterior approach that involved interposition a posterior cartilage for Type III or Type IV laryngotracheoesophageal cleft (LTEC). Methods: A chart view was performed on patients with Type III or Type IV LTEC between May 2017 and May 2022. Demographic features and surgical outcomes were collected and analyzed. Results: Seven patients were finally included. Five patients were diagnosed with Type III LTEC and two patients were diagnosed with Type IV LTEC. All but one patients survived and thrived. Four patients were able to successfully extubate with acceptable voice, and two patients were tracheostomized. Five patients were deemed safe for all consistencies food and one was safe for thickened food. After a mean follow-up of 49 months (18–83 months), neither complications nor recurrences were observed. Conclusion: An anterior laryngofissure approach to the cleft repair with a posterior cartilage grafting is an effective and safe treatment for Type III or IV LTEC, which enables closure of LTEC and reconstruction of cricoid plate in order to avoid tracheoesophageal fistula formation or subglottic stenosis postoperatively. Severe tracheomalacia and GERD are two main causes for surgical failure. [ABSTRACT FROM AUTHOR]

Background Chronic Otitis Media (COM) is one of the leading causes of hearing loss in the world. Tympanoplasty is the surgical treatment to repair the defective tympanic membrane in such patients. Aim To compare the healing and graft uptake using temporalis fascia versus cartilage perichondrium grafts in tympanoplasty type-1. Method A prospective randomized comparative cohort trial was conducted in the Department of Otorhinolaryngology at a Private Medical College in South India in the year 2020. This study compared the effect of two graft materials, tragal cartilage perichondrium and temporalis fascia, in tympanoplasty and evaluated the post-operative healing, among 60 patients randomized into 2 groups. Results 93% cases belonging to the cartilage perichondrium graft group had formation of neotympanum compared to only 53% cases in Temporalis fascia group. Statistically significant difference between the two groups in terms of formation of neotympanum suggests cartilage perichondrium was better in the aspect of healing and graft uptake. Conclusion Results of this study conclude that tragal cartilage perichondrium is significantly better than temporalis fascia in terms of graft uptake in cases of Type I Tympanoplasty. [ABSTRACT FROM AUTHOR]

Full-endoscopic lumbar interbody fusion (FELIF) is a critical yet challenging procedure. However, extensive analyses of discectomy and cartilage endplate preparation techniques are limited. This can be attributed to the lack of universal protocols owing to diverse surgical practices and equipment preferences. Therefore, this narrative review presents a comprehensive overview of discectomy and cartilage endplate preparation techniques in FELIF. A literature search of the PubMed, Embase, and Google Scholar databases in December 2023 retrieved 490 studies, of which 53 met the predefined inclusion criteria, and 1373 patients were included in the analyses. Spinal endoscopic disc and cartilage endplate removal can be categorized into 2 main types: removal under direct endoscopic visualization and removal under radiographic guidance with the protection of a working sheath following the endoscope's removal. Removal under direct visualization ensures the safety and precision of the procedure. Radiographic guidance can enhance the efficiency of the removal process. Specially designed instruments can be utilized through the narrow working channels of spinal endoscopes for the scraping surgery. Moreover, many traditional spinal endoscopic instruments, through specific techniques and manipulations, can also aid in cartilage removal. The approaches and techniques vary significantly among physicians, but overall, these instruments and techniques aim to achieve a safe and efficient disc-scraping outcome. Thus, this review may offer a comprehensive guidance to surgeons in selecting the most efficient practices for FELIF. Uniform procedural protocols are needed to ensure broader adoption and standardized practice. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this retrospective review was to determine the prevalence of osteochondral lesions (OCLs) of the lateral talar dome in patients with anterior ankle impingement with an associated hypertrophic distal fascicle of the anterior tibio‐fibular ligament. Methods: Retrospective chart review identified 40 patients who underwent anterior ankle arthroscopy for the management of anterior ankle impingement. Clinical outcomes assessed included pre‐ and postoperative foot and ankle outcome score (FAOS), visual analogue scale (VAS), complications, failures, secondary surgical procedures, return‐to‐work data and return‐to‐sport data. Results: Thirty‐two patients with a mean follow‐up time of 29.3 ± 10.4 months were included. The hypertrophic distal fascicle of the anterior tibio‐fibular ligament was hypertrophic in 29 patients (90.6%), with a mean thickness of 2.5 ± 0.4 mm on MRI. There were 22 OCLs of the lateral talar dome (75.9%) with an associated hypertrophic distal fascicle of the anterior tibio‐fibular ligament visualized during arthroscopy. The international cartilage repair society gradings of the lesions included 3 (13.6%) grade I lesions, 15 (68.1%) grade II lesions, 3 (13.6%) grade III lesions, and 1 (4.6%) grade IV lesion. There was a statistically significant improvement in mean FAOS and VAS scores from preoperative to postoperative (p < 0.001). No cases of syndesmotic instability were observed following resection of hypertrophic distal fascicle of the anterior tibio‐fibular ligament. Conclusion: This retrospective case series demonstrated that a hypertrophic distal fascicle of the anterior tibio‐fibular ligament was associated with an OCL of the lateral talar dome identified during arthroscopic evaluation. In addition, preoperative MRI demonstrated poor sensitivity for the detection of these OCLs. Heightened awareness is warranted for potential lateral talar dome OCLs in patients presenting with anterolateral ankle impingement with a hypertrophic ATiFLdf identified on preoperative MRI in the absence of an associated OCLs. Level of Evidence: Level IV, Retrospective case series. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the risk factors for varus progression after arthroscopic medial meniscal posterior root tear (MMPRT) repair and to compare the clinical outcomes between two groups: one with more varus progression and the other with less varus progression. Methods: Patients who underwent isolated arthroscopic repair of MMPRT between 2015 and 2020 were enroled, and 2‐year follow‐up data were collected. Participants were categorized into two groups based on preoperative values of the weight‐bearing line (WBL) ratio: group A with <5.9% increase and group B with ≥5.9% increase. Various factors, including demographic features and radiological findings, were analysed and compared between the two groups. Intra‐meniscal signal intensity, meniscal healing, medial meniscal extrusion (MME), and articular cartilage grade were assessed preoperatively and 1‐year postoperatively using coronal magnetic resonance imaging. Results: The final cohort consisted of 34 patients in group A and 46 in group B, with a mean age of 55.8 ± 11.2 and 59.8 ± 6.6 years, respectively. Preoperative WBL ratio and cartilage lesions in the medial compartment did not differ between the groups. Preoperative MME were significantly lower in group A than those in group B (2.6 ± 0.6 mm in group A and 3.5 ± 0.7 mm in group B, p < 0.05). Patient‐reported outcomes at the 2‐year follow‐up did not differ between the two groups (n. s.). In a logistic analysis, the odds ratio of MME was 2.1 (p < 0.05), and the cutoff value of MME was 3.02 mm. Conclusion: Preoperative MME is a risk factor for varus progression. However, no differences in patient‐reported outcomes were observed at 2‐year follow‐up, even in the group with greater varus progression. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated whether preoperative radiographs accurately predicted intra-articular cartilage damage in varus knees. Methods: The study assessed 181 knees in 156 patients who underwent total knee arthroplasty. Cartilage damage was graded by two examiners with the International Cartilage Repair Society classification; one used knee radiographs and the other used intraoperative photographs. It was then determined if this radiographic cartilage assessment over- or underestimated the actual damage severity. Knee morphological characteristics affecting radiographic misestimation of damage severity were also identified. Results: The concordance rate between radiographic and intraoperative assessments of the medial femoral condyle was high, at around 0.7. Large discrepancies were found for the lateral femoral condyle and medial trochlear groove. Radiographic assessment underestimated cartilage damage on the medial side of the lateral femoral condyle due to a large lateral tibiofemoral joint opening and severe varus alignment {both r = −0.43}. Medial trochlear damage was also underdiagnosed, in cases of residual medial tibiofemoral cartilage and shallow medial tibial slope {r = −0.25 and −0.21, respectively}. Conclusions: Radiographic evaluation of knee osteoarthritis was moderately practical using International Cartilage Repair Society grades. Lateral femoral condyle and medial trochlear cartilage damage tended to be misestimated, but considering morphologic factors might improve the diagnostic rate. [ABSTRACT FROM AUTHOR]

In the pathogenesis of osteoarthritis, various signaling pathways may influence the bone joint through a common terminal pathway, thereby contributing to the pathological remodeling of the joint. Semaphorins (SEMAs) are cell-surface proteins actively involved in and primarily responsible for regulating chondrocyte function in the pathophysiological process of osteoarthritis (OA). The significance of the SEMA family in OA is increasingly acknowledged as pivotal. This review aims to summarize the mechanisms through which different members of the SEMA family impact various structures within joints. The findings indicate that SEMA3A and SEMA4D are particularly relevant to OA, as they participate in cartilage injury, subchondral bone remodeling, or synovitis. Additionally, other elements such as SEMA4A and SEMA5A may also contribute to the onset and progression of OA by affecting different components of the bone and joint. The mentioned mechanisms demonstrate the indispensable role of SEMA family members in OA, although the detailed mechanisms still require further exploration. [ABSTRACT FROM AUTHOR]

Background and Aims: Multi-ligament knee injuries (MLKI) are serious and challenging to manage. This study aimed to elucidate the impact of surgical timing on both early and long-term outcomes following an MLKI. Methods: A comprehensive search strategy was employed across PubMed, Scopus, Web of Science, and the Cochrane Library. Studies were identified using a combination of relevant keywords encompassing "multi-ligament knee injury," "knee dislocation," "reconstruction," "repair," "surgery," and "timing," and their synonyms, along with appropriate Boolean operators. Selection of articles (systematic reviews and meta-analyses) adhered to predefined inclusion and exclusion criteria. Furthermore, a meta-analysis was conducted utilizing data extracted from primary studies. Results: Early surgery for MLKI demonstrated a significant advantage over delayed surgery, reflected by significantly higher Lysholm scores (Mean Difference [MD] 3.51; 95% Confidence Interval [CI] 1.79, 5.22), IKDC objective scores (Mantel–Haenszel Odds Ratio [MH-OR] 2.95; 95% CI 1.30, 6.69), Tegner activity scores (MD 0.38; 95% CI 0.08, 0.69), and Mayer's ratings (MH-OR 5.47; 95% CI 1.27, 23.56). In addition, we found a significantly reduced risk of secondary chondral lesions (MH-OR 0.33; 95% CI 0.23, 0.48), lower instrumented anterior tibial translation in the early surgery group (MD −0.92; 95% CI −1.83, −0.01), but no significant difference was observed in the secondary meniscal tears, between the two groups. However, the early surgery group also exhibited a significantly increased risk of knee stiffness (MH-OR 2.47; 95% CI 1.22, 5.01) and a greater likelihood of requiring manipulation under anaesthesia (MH-OR 3.91; 95% CI 1.10, 13.87). Conclusion: Early surgery for MLKI improves function, and stability, and reduces further articular cartilage damage, but increases the risk of stiffness. Level of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The triticeal cartilage, situated within the lateral thyrohyoid membrane, remains elusive in function yet crucial in clinical contexts. Composed of hyaline cartilage, it is prone to ossification, potentially leading to diagnostic challenges such as misidentification with atherosclerosis or fractures. Methods: This study, aiming to establish its prevalence and highlight clinical relevance, conducted a systematic review across several electronic databases such as Medline, PUBMED, Scopus, Google Scholar, Web of Science, SpringerLink and Sciencedirect using keywords "triticeal cartilage", "triticeous cartilage" or "cartilago triticea". An assurance tool for anatomical investigations was used to assess the quality of the methodology (AQUA). A random effects model was utilized to determine the pooled prevalence. Results: The true prevalence of triticeal cartilage was found to be variable, with an overall pooled proportion of 43% while crude prevalence were 50.6%. Its crude prevalence was notably higher in women compared to men, in contrary true prevalence was higher in men, posing sex-related disparities. It was mostly seen bilaterally. When the morphologic characteristics of the cartilage were evaluated, classification differences were observed in terms of shape, with a mean length of 5.48 mm, a mean width of 3.04 mm and a mean weight of 62.32 mg. The vertebral level at which the TC was located was mostly C4. The degree of calcification of the cartilage was most commonly mild. Conclusion: In conclusion, triticeal cartilage holds significant clinical importance, necessitating vigilance during diagnostic evaluations and surgical approaches. Further studies are imperative to elucidate its function comprehensively and refine diagnostic strategies, ensuring optimal patient care in neck-related pathologies. [ABSTRACT FROM AUTHOR]

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity. [ABSTRACT FROM AUTHOR]

Osteoarthritis is a common and complex joint disorder that shows higher prevalence and greater disease severity in women. Here, we investigate genome-wide methylation profiles of primary chondrocytes from osteoarthritis patients. We compare genome-wide methylation profiles of macroscopically intact (low-grade) and degraded (high-grade) osteoarthritis cartilage samples matched from osteoarthritis patients undergoing knee replacement surgery. We perform an epigenome-wide association study for cartilage degeneration across 170 patients and separately in 96 women and 74 men. We reveal widespread epigenetic differences with enrichments of nervous system and apoptosis-related processes. We further identify substantial similarities between sexes, but also sex-specific markers and pathways. Together, we provide the largest genome-wide methylation profiles of primary cartilage to date with enhanced and sex-specific insights into epigenetic processes underlying osteoarthritis progression. [ABSTRACT FROM AUTHOR]

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females. We compiled clinical data from multiple tissues within the knee joint—since OA is a whole joint disorder—aiming to reveal relevant factors behind the sex differences from different perspectives. The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures. We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life. [ABSTRACT FROM AUTHOR]

Understanding gender-specific differences in patterns of cartilage loss can improve our knowledge of the pathogenesis of knee osteoarthritis (KOA) development and progression and may inform clinical trials of treatments for KOA. The goal of our observational study was to examine gender differences in patterns of cartilage loss in the central weight-bearing regions of the femur. We measured cartilage volume change in the indexed knee of 700 subjects with Kellgren-Lawrence 1, 2, or 3 from the Osteoarthritis Initiative for four follow-up periods (baseline [BL] to 24 mo, BL to 48 mo, BL to 72 mo, and BL to 96 mo) using the local area cartilage segmentation (LACS) method. Briefly, the LACS method uses robust coordinate systems fixed to anatomical landmarks to measure patterns of change in cartilage volume in sub-regions using responsiveness heat maps. We observed a statistically significant gender difference in cartilage change in the medial femur (MF), lateral femur (LF), and medial tibia. The heat maps showed loss was primarily in the posterior central weight-bearing portion of the LF and more general in the LT and MF. Similar patterns were observed for each of the four follow-up periods. The LACS method was capable of illustrating gender-specific differences in patterns of cartilage loss that may offer insight into the variation of gender differences in the natural history of KOA and may be useful in evaluating the benefit of interventions for KOA. [ABSTRACT FROM AUTHOR]

Purpose: The anisotropy of R2 and R1ρ relaxation rates in articular cartilage contains information about the collagenous structure of the tissue. Here we determine and study the anisotropic and isotropic components of T2 and T1ρ relaxation parameters in articular cartilage with a clinical 3T MRI device. Furthermore, a visual representation of the topographical variation in anisotropy is given via anisotropy mapping. Methods: Eight bovine stifle joints were imaged at 22 orientations with respect to the main magnetic field using T2, continuous‐wave (CW) T1ρ, and adiabatic T1ρ mapping sequences. Relaxation rates were separated into isotropic and anisotropic relaxation components using a previously established relaxation anisotropy model. Pixel‐wise anisotropy values were determined from the relaxation‐time maps using Michelson contrast. Results: The relaxation rates obtained from the samples displayed notable variation depending on the sample orientation, magnetization preparation, and cartilage layer. R2 demonstrated significant anisotropy, whereas CW‐R1ρ (300 Hz) and CW‐R1ρ (500 Hz) displayed a low degree of anisotropy. Adiabatic R1ρ was largely isotropic. In the deep cartilage regions, relaxation rates were generally faster and more anisotropic than in the cartilage closer to the tissue surface. The isotropic relaxation rate components were found to have similar values regardless of measurement sequence. Conclusions: The fitted relaxation model for T2 and T1ρ demonstrated varying amounts anisotropy, depending on magnetization preparation, and studied the articular cartilage layer. Anisotropy mapping of full joints showed varying amounts of anisotropy depending on the quantitative MRI parameter and topographical location, and in the case of T2, showed systematic changes in anisotropy across cartilage depth. [ABSTRACT FROM AUTHOR]

Advancements in personalized medicine, threedimensional (3D) printing, miniaturization, and robot-assisted surgery are driving innovation in tissue engineering. A novel approach, known as in situ printing, focuses on the direct deposition of materials at the surgical site. Using the in situ printing approach, bone and/or cartilage defects can be addressed with high precision. Furthermore, highly customized 3D printed tissue constructs or implants can be deposited directly inside the body. Currently, most applications of in situ printing are limited to areas near the skin or open surgeries. Even though a minimally invasive approach would bring clinical benefits, only a few research groups have focused on this field. In this scoping review, we provide an overview of the current state of in situ minimally invasive 3D printing technology for bone and cartilage regeneration and discuss its advantages and current challenges. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) injuries are associated with a risk of post-traumatic osteoarthritis due to chondral damage. Magnetic resonance imaging (MRI) techniques provide excellent visualization and assessment of cartilage and can detect subtle and early chondral damage. This is often preceding clinical and radiographic post-traumatic osteoarthritis. Hypothesis: Morphologic and quantitative MRI techniques can assess early and progressive degenerative chondral changes after acute ACL injury. Study Design: Prospective longitudinal cohort. Level of Evidence: Level 3. Methods: Sixty-five participants with acute unilateral ACL injuries underwent bilateral knee MRI scans within 1 month of injury. Fifty-seven participants presented at 6 months, while 54 were evaluated at 12 months. MRI morphologic evaluation using a modified Noyes score assessed cartilage signal alteration, chondral damage, and subchondral bone status. Quantitative T1ρ and T2 mapping at standardized anatomic locations in both knees was assessed. Participant-reported outcomes at follow-up time points were recorded. Results: Baseline Noyes scores of MRI detectable cartilage damage were highest in the injured knee lateral tibial plateau (mean 2.5, standard error (SE) 0.20, P < 0.01), followed by lateral femoral condyle (mean 2.1, SE 0.18, P < 0.01), which progressed after 1 year. Longitudinal prolongation at 12 months in the injured knees was significant for T1ρ affecting the medial and lateral femoral condyles (P < 0.01) and trochlea (P < 0.01), whereas T2 values were prolonged for medial and lateral femoral condyles (P < 0.01) and trochlea (P < 0.01). The contralateral noninjured knees also demonstrated T1ρ and T2 prolongation in the medial and lateral compartment chondral subdivisions. Progressive chondral damage occurred despite improved patient-reported outcomes. Conclusion: After ACL injury, initial and sustained chondral damage predominantly affects the lateral tibiofemoral compartment, but longitudinal chondral degeneration also occurred in other compartments of the injured and contralateral knee. Clinical Relevance: Early identification of chondral degeneration post-ACL injury using morphological and quantitative MRI techniques could enable interventions to be implemented early to prevent or delay PTOA. [ABSTRACT FROM AUTHOR]

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Nowadays, the world is struggling with the problems of an aging society. With the increasing share of older people in the population, degenerative joint diseases are a growing problem. The result of progressive degenerative changes in joints is primarily the deterioration of the patients' quality of life and their gradual exclusion from activity and social life. The ability to effectively, non-invasively and quickly detect cases of chondromalacia of the knee joints is a challenge for modern medicine. The possibility of early detection of progressive degenerative changes allows for the appropriate selection of treatment protocols and significantly increases the chances of inhibiting the development of degenerative diseases of the musculoskeletal system. The article presents a non-invasive method for detecting degenerative changes in the knee joints based on recurrence analysis and classification using neural networks. The result of the analyses was a classification accuracy of 91.07% in the case of multilayer perceptron (MPL) neural networks and 80.36% for radial basis function (RBF) networks. [ABSTRACT FROM AUTHOR]

Physics-based modeling methods have the potential to investigate the mechanical factors associated with knee osteoarthritis (OA) and predict the future radiographic condition of the joint. However, it remains unclear what level of detail is optimal in these methods to achieve accurate prediction results in cohort studies. In this work, we extended a template-based finite element (FE) method to include the lateral and medial compartments of the tibiofemoral joint and simulated the mechanical responses of 97 knees under three conditions of gait loading. Furthermore, the effects of variations in cartilage thickness and failure equation on predicted cartilage degeneration were investigated. Our results showed that using neural network-based estimations of peak knee loading provided classification performances of 0.70 (AUC, p < 0.05) in distinguishing between knees that developed severe OA or mild OA and knees that did not develop OA eight years after a healthy radiographic baseline. However, FE models incorporating subject-specific femoral and tibial cartilage thickness did not improve this classification performance, suggesting there exists an optimal point between personalized loading and geometry for discrimination purposes. In summary, we proposed a modeling framework that streamlines the rapid generation of individualized knee models achieving promising classification performance while avoiding motion capture and cartilage image segmentation. [ABSTRACT FROM AUTHOR]

Purpose of Review: To reduce pain, improve function and possibly mitigate the risk for development of osteoarthritis in patients with functionally deficient meniscus pathology, meniscal allograft transplantation (MAT) can be used to restore native joint biomechanics and increase knee joint longevity. This review explores the senior author's preferred bridge-in-slot technique and recently published long-term clinical and radiographic outcomes following MAT. Recent Findings: Recent literature demonstrates MAT to be a safe and largely successful procedure for patients with functional meniscus deficiency. A majority of patients reach established minimal clinically important difference (MCID) values. Graft survivorship is approximately 80% at 10 years, significantly delaying and in some cases, preventing the need for future joint reconstruction procedures in these young patients. Return to sport rates are over 70%, revealing meniscal allografts can withstand high impact activities. Cartilage damage at the time of MAT increases the risk for graft and clinical failure, though this may be mitigated with a concomitant cartilage restoration procedure. Summary: Meniscal allograft transplantation can provide a durable and effective long-term solution to meniscal deficiency in symptomatic patients who wish to decrease the risk of symptomatic progression and possibly further osteoarthritis and continue activities of daily life and sports with less pain and more function. By restoring more normal joint biomechanics, MAT can mitigate the potential need for future knee arthroplasty in this young active patient population. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a prevalent cause of joint algesia, loss of function, and disability in adults, with cartilage injury being its core pathological manifestation. Since cartilage damage is non-renewable, the treatment outcome in the middle and late stages of OA is unsatisfactory, which can be minimized by changing lifestyle and other treatment modalities if diagnosed and managed in the early stages, indicating the importance of early diagnosis and monitoring of cartilage injury. Ultrasound technology has been used for timely diagnosis and even cartilage injury treatment, which is convenient and safe for the patient owing to no radiation exposure. Studies have demonstrated the effectiveness of ultrasound and its various quantitative ultrasound parameters, like ultrasound roughness index (URI), reflection coefficient (R), apparent integrated backscatter (AIB), thickness, and ultrasound elastography, in the early and accurate assessment of OA cartilage pathological changes, including surface and internal tissue, hardness, and thickness. Although many challenges are faced in the clinical application of this technology in diagnosis, ultrasound and ultrasound-assisted techniques offer a lot of promise for detecting early cartilage damage in OA. In this review, we have discussed the evaluation of ultrasonic cartilage quantitative parameters for early pathological cartilage changes. [ABSTRACT FROM AUTHOR]

Several studies describe the development of the chondrocranium of vertebrates. The details in these studies vary a lot, which makes it hard to compare developmental patterns and identify evolutionary trends. Therefore, we aim to close this gap for anurans, which is the largest order of amphibians. We present here a detailed description of the chondrocranium morphology and development of Smilisca phaeota, the New Granada cross-banded tree frog. The anatomy was described for the larvae at or older than Gossner stage 31 and before ossification starts. Following this, we describe the development of the chondrocranium from Gossner stages 19–26. Early in Gossner stage 19 no precursors of any cartilages are visible, while later in that stage the mesodermal Anlage of Meckel's cartilage was observed. In the subsequent stages more and more mesodermal anlagen become identifiable, followed by chondrification, and final differentiation of the cartilage elements. We used serial sections to study all the developmental stages and additionally utilized cleared and stained specimens and CT scan data. The latter were also used for the 3D reconstruction of the chondrocranium. We previously studied several species and compared these developmental patterns with S. phaeota, revealing potentially characteristic patterns significant for Lalagobatrachia, a clade that includes over 7000 frog species. These include (1) the suprarostral alae develop before the suprarostral corpus, (2) the infrarostral cartilage chondrifies late, after the chondrification of ceratobranchial 1, and (3) the ceratohyal body is the first element to show chondrocytes and to chondrify. However, with only six species studied so far, our data only provide a basis for future studies and developing hypotheses about the ancestral developmental pattern in anurans. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate tibial cartilage thickness (TCT), T1ρ and T2 values within both loaded and baseline configurations in a cadaveric knee model using a 3D bone based tibial coordinate system. Ten intact cadaveric knees were mounted into an magnetic resonance imaging (MRI) compatible loading device. Morphologic and quantitative MRI (qMRI) images were acquired with the knee in a baseline configuration and after application of 50% body weight. The morphologic images were evaluated for cartilage degeneration using a modified Noyes scoring system. A 3D bone‐based tibial coordinate system was utilized to evaluate regional changes of tibial T1ρ, T2, and cartilage thickness values among regions covered and uncovered by the meniscus. Inter‐regional differences in medial and lateral MRI outcomes were found between loaded and baseline configurations. Cartilage regions covered by the meniscus demonstrated disparate qMRI and TCT results as compared to cartilage regions not covered by the meniscus. The regions covered by meniscus experienced a ~3.5%, ~0.5%, and ~5.5% reduction of T1ρ (p < 0.05, medial and lateral compartments), T2 and TCT, respectively, in both compartments while regions not covered by the meniscus experienced larger reductions of ~10%, ~2%, and ~10.5% reduction of T1ρ (p < 0.05, medial and lateral compartments), T2 and TCT (p < 0.05, lateral compartment only), respectively, in both compartments. T1ρ and T2 decreases following application of 50% body weight load were substantially larger in the tibial regions with modified Noyes grade 3 (n = 2) compared to either healthy regions (n = 85, p < 0.0.003) or regions with modified Noyes grade 2 (n = 13, p < 0.004). Interregional differences in MRI outcomes reflect variations in structure and function, and largely followed a pattern in cartilage regions that were covered or not covered by the meniscus. Results of the current study suggest that ΔT1ρ and ΔT2 values may be sensitive to superficial fissuring, more than baseline or loaded T1ρ or T2 values, or TCT alone, however future studies with additional specimens, with greater variability in OA grade distribution, may further emphasize the current findings. [ABSTRACT FROM AUTHOR]

Natural cartilage exhibits superior lubricity as well as an ultra‐long service lifetime, which is related to its surface hydration, load‐bearing, and deformation recovery feature. Until now, it is of great challenge to develop reliable cartilage lubricating materials or coatings with persistent robustness. Inspired by the unique biochemical structure and mechanics of natural cartilage, the study reports a novel cartilage‐hydrogel composed of top composite lubrication layer and bottom mechanical load‐bearing layer, by covalently manufacturing thick polyelectrolyte brush phase through sub‐surface of tough hydrogel matrix with multi‐level crystallization phase. Due to multiple network dissipation mechanisms of matrix, this hydrogel can achieve a high compression modulus of 11.8 MPa, a reversible creep recovery (creep strain: ≈2%), along with excellent anti‐swelling feature in physiological medium (v/v0 < 5%). Using low‐viscosity PBS as lubricant, this hydrogel demonstrates persistent lubricity (average COF: ≈0.027) under a high contact pressure of 2.06 MPa with encountering 100k reciprocating sliding cycles, negligible wear and a deformation recovery of collapse pit in testing area. The extraordinary lubrication performance of this hydrogel is comparable to but beyond the natural animal cartilage, and can be used as compliant coating for implantable articular material of UHMWPE to present, offering more robust lubricity than current commercial system. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusions Level of Evidence The associated damage to articular cartilage in anterior cruciate ligament (ACL) injured patients is a well‐recognized phenomenon; however, there is a relative paucity in the literature regarding the different treatment techniques and outcomes. The purpose of this systematic review was to identify patients treated for acute ACL rupture and associated cartilage injury, with interest in the surgical management of these chondral injuries and any difference in patient‐reported outcome measures (PROMs) differing techniques.A systematic review was performed looking for treatment or management of International Cartilage Repair Society grade 3 or 4 articular cartilage injury at the time of ACL reconstruction.Seventeen studies fit the criteria, a total of 892 patients were included, 64.6% were male with a mean age of 33.7 and the average time to follow‐up was 41.7 months. 68.2% of the lesions were on the medial femoral condyle (MFC) with a mean lesion size of 3.9 cm2. Six different operative methods of dealing with chondral lesions were identified, there was no significant difference in PROMs between the techniques, although there was a significant difference between the preoperative and postoperative outcome measures.The systematic review found that chondral defects on the MFC are more common in concomitant ACL injuries, despite the pattern of bone bruising being more common on the lateral femoral condyle as reported in the literature. It also found no significant difference in the PROMs between the six different techniques identified for the concomitant management of ACL reconstruction and chondral defects.Level II. [ABSTRACT FROM AUTHOR]

In this study, Poly(vinyl alcohol)/cellulose nanofiber (PVA/CNF) hydrogels have been successfully prepared using γ-ray irradiation, annealing, and rehydration processes. In addition, the effects of CNF content and annealing methods on the hydrogel properties, including gel fraction, micromorphology, crystallinity, swelling behavior, and tensile and friction properties, are investigated. Consequently, the results show that at an absorbed dose of 30 kGy, the increase in CNF content increases the gel fraction, tensile strength, and elongation at break of irradiated PVA/CNF hydrogels, but decreases the water absorption. In addition, the cross-linking density of the PVA/CNF hydrogels is significantly increased at an annealing temperature of 80 °C, which leads to the transition of the cross-sectional micromorphology from porous networks to smooth planes. For the PVA/CNF hydrogel with a CNF content of 0.6%, the crystallinity increases from 19.9% to 25.8% after tensile annealing of 30% compared to the original composite hydrogel. The tensile strength is substantially increased from 65.5 kPa to 21.2 MPa, and the modulus of elasticity reaches 4.2 MPa. Furthermore, it shows an extremely low coefficient of friction (0.075), which suggests that it has the potential to be applied as a material for artificial joint cartilage. [ABSTRACT FROM AUTHOR]

Even after successful surgery for acute ankle fractures, many patients continue having complaints. A possible explanation is the presence of concomitant chondral lesions. The aim of this study is to investigate the accuracy of MRI compared to that of arthroscopy in the assessment of chondral lesions in acute ankle fractures. In this prospective single-center study, patients presenting with acute ankle fractures over a period of three years were identified. A preoperative MRI was performed within a maximum of 10 days after trauma. During surgery, ankle arthroscopy was also performed. The International Cartilage Repair Society (ICRS) cartilage lesion classification was used to grade the detected chondral lesions. To localize the chondral lesions, the talar dome was divided into eight zones and the tibial/fibular articular surfaces into three zones. In total, 65 patients (28 females) with a mean age of 41.1 ± 15 years were included. In the MRI scans, 70 chondral lesions were detected (69.2% of patients) affecting mostly the tibial plafond (30%) and mostly graded as ICRS 3. The mean lesion area measured was 20.8 mm2. In the arthroscopy, 85 chondral lesions were detected (70.8% of patients) affecting mostly the medial surface of the talar dome (25.9%) and mostly graded ICRS 3. The mean lesion area measured was 43.4 mm2. The highest agreement between the two methods was observed in the size estimation of the chondral lesions. The present study shows the reduced accuracy of MRI when compared to arthroscopy in the assessment of traumatic chondral lesions in the setting of acute ankle fractures especially regarding lesion size. MRI remains an essential instrument in the evaluation of such lesions; however, surgeons should take this discrepancy into consideration, particularly the underestimation of chondral lesions' size in the preoperative planning of surgical treatment and operative technique. [ABSTRACT FROM AUTHOR]

(1) Background: The objective of this study is to evaluate the predictive value of the Eaton–Littler radiologic classification for thumb carpometacarpal osteoarthritis (CMC OA) relating to intra-articular cartilage damage assessed by the Outerbridge arthroscopic classification. (2) Methods: A total of 51 thumb CMC OA arthroscopies were performed on patients classified as Eaton stages 1, 2, or 3. Post-arthroscopic evaluations of cartilage damage were categorized using the Outerbridge classification. Comparative analyses were conducted between the radiological Eaton stages and the arthroscopic Outerbridge stages. (3) Results: Arthroscopic examination revealed Outerbridge stage 3 and 4 cartilage damage in 26 cases classified as Eaton stage 2 and in 18 cases classified as Eaton stage 3. The detection of severe cartilage damage in patients classified as Eaton stage 2 was unexpected. (4) Conclusions: Arthroscopy demonstrated that many patients with mild radiological degenerative signs exhibited significant cartilage destruction. Although the Eaton classification is widely used for staging thumb CMC OA, it may not accurately reflect the severity of intra-articular damage. The Eaton classification does not reliably predict intra-articular damage in Eaton stage 2 cases. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Discussion Level of Evidence Kinematically aligned total knee arthroplasty (KA TKA), as a pure resurfacing procedure, is based on matching implant thickness with bone cut and kerf thickness, plus cartilage wear. However, the assumption of a consistent 2 mm femoral cartilage thickness remains unproven. This study aimed to systematically review the available literature concerning magnetic resonance imaging (MRI) assessment of femoral cartilage thickness in non‐arthritic patients. Our hypothesis was that cartilage thickness values would vary significantly among individuals, thereby challenging the established KA paradigm of ‘one‐cartilage‐fits‐all’.Systematic literature searches (Pubmed, Scopus and Cochrane Library) followed PRISMA guidelines. English‐language studies assessing distal and posterior femoral cartilage thickness using MRI in non‐arthritic adults were included. Studies lacking numerical cartilage thickness data, involving post‐operative MRI, considering total femoro‐tibial cartilage thickness, or failing to specify the compartment of the knee being studied were excluded.Overall, 27 studies comprising 8170 MRIs were analysed. Weighted mean femoral cartilage thicknesses were: 2.05 ± 0.62 mm (mean range 1.06–2.6) for the distal medial condyle, 1.95 ± 0.4 mm (mean range 1.15–2.5) for the distal lateral condyle, 2.44 ± 0.5 mm (mean range 1.37–2.6) for the posterior medial condyle and 2.27 ± 0.38 mm (mean range 1.48–2.5) for the posterior lateral condyle.Femoral cartilage thickness varies significantly across patients. In KA TKA, relying on a fixed thickness of 2 mm may jeopardize the accurate restoration of individual anatomy, leading to errors in implant coronal and rotational alignment. An intraoperative assessment of cartilage thickness may be advisable to express the KA philosophy at its full potential.Level IV. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is one of the most common causes of disability around the globe, especially in aging populations. The main symptoms of OA are pain and loss of motion and function of the affected joint. Hyaline cartilage has limited ability for regeneration due to its avascularity, lack of nerve endings, and very slow metabolism. Total joint replacement (TJR) has to date been used as the treatment of end-stage disease. Various joint-sparing alternatives, including conservative and surgical treatment, have been proposed in the literature; however, no treatment to date has been fully successful in restoring hyaline cartilage. The mechanical and frictional properties of the cartilage are of paramount importance in terms of cartilage resistance to continuous loading. OA causes numerous changes in the macro- and microstructure of cartilage, affecting its mechanical properties. Increased friction and reduced load-bearing capability of the cartilage accelerate further degradation of tissue by exerting increased loads on the healthy surrounding tissues. Cartilage repair techniques aim to restore function and reduce pain in the affected joint. Numerous studies have investigated the biological aspects of OA progression and cartilage repair techniques. However, the mechanical properties of cartilage repair techniques are of vital importance and must be addressed too. This review, therefore, addresses the mechanical and frictional properties of articular cartilage and its changes during OA, and it summarizes the mechanical outcomes of cartilage repair techniques. [ABSTRACT FROM AUTHOR]

Introduction: This present research was designed to investigate the antiinflammatory and immune-modulatory effects of a 50% hydroethanolic extract of "Gola" guava fruit (GF50%) and guava leaf (GL50%) against papain-induced knee osteoarthritis (KOA). Methods: Sixty Sprague-Dawley rats were divided into five groups (10 rats/group): T0 (negative control), T1 (positive control), T2 (200 mg/kg GF50%), T3 (400 mg/kg GF50%), T4 (200 mg/kg GL50%), and T5 (400 mg/kg GL50%). Physical parameters were evaluated throughout the trial, while biochemical, histopathological, and radiographic analyses were performed at 0, 15, and 30 days. The histopathological and radiographic analyses were evaluated using the Osteoarthritis Research Society International (OARSI) score and Kellgren-Lawrence (KL) classification systems, respectively. Results and discussion: The T1 group demonstrated a significant increase in knee diameter, confirming successful OA induction. The T5 group maintained a significantly lower body weight at day 30, and the T3 group exhibited the highest weight gain. The high dose of GL50% (400 mg/kg) effectively reduced knee inflammation and significantly downregulated myeloperoxidase (MPO), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). In contrast, it significantly (p < 0.001) upregulated the serum and knee capsule tissue superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). In addition, histopathological and X-ray examinations also confirmed the chondroprotective potential of GL50% extract against OA. Consequently, 400 mg/kg GL50% exhibited anti-inflammatory and chondroprotective potential by lowering oxidative stress and pro-inflammatory cytokines and elevating antioxidant status. These findings could provide a theoretical basis for understanding the mechanism and potential medicinal value of guava fruit and leaf in treating KOA. [ABSTRACT FROM AUTHOR]

Recent research on ferroptosis and cuproptosis has underscored the crucial role of trace element regulation in osteoarthritis (OA) treatment. However, research systematically addressing the alterations in nutrient elements in OA cartilage is lacking. This study is initiated using clinical specimens to quantify metal element concentrations in both damaged and intact cartilage to identify deficient trace elements within the inflammatory and senescent microenvironments of OA. Based on the preliminary findings of selenium (Se) and gallium (Ga) deficiencies in OA cartilage, tailored nanoparticles based on Se and Ga are designed and validated for their antioxidant ability. GaSex nanoparticles demonstrated significant efficacy in mitigating chondrocyte degeneration and extracellular matrix degradation induced by inflammatory factors and in alleviating cartilage abrasion, hyperalgesia, and abnormal gait in a destabilization of the medial meniscus (DMM) mouse model. Mechanistically, GaSex nanoparticles activated the Nrf2 pathway and competitively inhibited the ubiquitin‐mediated degradation of Gpx4, thus inhibiting ferroptosis. This study systematically designed GaSex nanoparticles based on the imbalance of trace elements within the OA knee joint microenvironment and demonstrated robust antioxidant capabilities and remarkable competitive properties for ubiquitin, thereby providing a novel therapeutic solution for OA treatment. [ABSTRACT FROM AUTHOR]