Ear keloid and epidermal cyst following auricular cartilage harvest for rhinoplasty:A case report

BACKGROUND This case report highlights a rare instance of concurrent keloid and epidermal cyst development at an ear cartilage harvest site following rhinoplasty in a 25-year-old woman.Both conditions,which typically stem from skin trauma,seldom occur together,demonstrating the exceptional characteristics of this case.CASE SUMMARY The patient underwent successful surgical removal of both the keloid and the epidermal cyst.Postoperative treatment included the use of silicone sheets,gel,and oral tranilast to reduce scarring.No recurrence was observed over a 6-mo follow-up period,indicating effective management of the condition.CONCLUSION The effective management of complex skin trauma cases underscores the need for individualized treatment strategies in plastic surgery.

Clinical study on improving the diagnostic accuracy of adult elbow joint cartilage injury by multisequence magnetic resonance imaging

BACKGROUND Due to frequent and high-risk sports activities,the elbow joint is susceptible to injury,especially to cartilage tissue,which can cause pain,limited movement and even loss of joint function.AIM To evaluate magnetic resonance imaging(MRI)multisequence imaging for improving the diagnostic accuracy of adult elbow cartilage injury.METHODS A total of 60 patients diagnosed with elbow cartilage injury in our hospital from January 2020 to December 2021 were enrolled in this retrospective study.We analyzed the accuracy of conventional MRI sequences(T1-weighted imaging,T2-weighted imaging,proton density weighted imaging,and T2 star weighted image)and Three-Dimensional Coronary Imaging by Spiral Scanning(3D-CISS)in the diagnosis of elbow cartilage injury.Arthroscopy was used as the gold standard to evaluate the diagnostic effect of single and combination sequences in different injury degrees and the consistency with arthroscopy.RESULTS The diagnostic accuracy of 3D-CISS sequence was 89.34%±4.98%,the sensitivity was 90%,and the specificity was 88.33%,which showed the best performance among all sequences(P<0.05).The combined application of the whole sequence had the highest accuracy in all sequence combinations,the accuracy of mild injury was 91.30%,the accuracy of moderate injury was 96.15%,and the accuracy of severe injury was 93.33%(P<0.05).Compared with arthroscopy,the combination of all MRI sequences had the highest consistency of 91.67%,and the kappa value reached 0.890(P<0.001).CONCLUSION Combination of 3D-CISS and each sequence had significant advantages in improving MRI diagnostic accuracy of elbow cartilage injuries in adults.Multisequence MRI is recommended to ensure the best diagnosis and treatment.

Endoscopic push through tragal cartilage tympanoplasty: A 10-year retrospective review of our technique and outcomes

BACKGROUND Endoscopic ear surgery(EES)provides a magnified,high-definition view of the otological surgical field.EES allows otologists to avoid surgical incisions and associated postoperative complications.It is an ideal technique for the perfor-mance and teaching of tympanoplasty.AIM To examine the efficacy of total Endoscopic Push Through Tragal Cartilage Tympanoplasty(EPTTCT),at our institution over a 10-year period.METHODS A retrospective analysis of 168 cases of EPTTCT for closure of small to medium tympanic membrane perforations from 2013-2023 was conducted.Patient sex,age range(pediatric vs adult),etiology of injury,success rate,complications,and postoperative hearing status were collected.RESULTS Graft uptake results indicated success in 94%of patients,with less than a 2%complication rate.Postoperative pure tone audiometry demonstrated hearing status improvement in 69%of patients.CONCLUSION EPTTCT has been shown to be effective in tympanic membrane perforation closures with minimal complications.This study further demonstrates the efficacy and safety of these procedures in a single-center review.

Nano“Undercover Agents”Lodge in Cartilage to Treat Osteoarthritis

The relentless pain and disability caused by osteoarthritis stem from the body’s own cartilage cells going rogue under inflammatory conditions.They secrete enzymes that devour the cushioning cartilage matrix,leading to joint damage.Conventional drugs cannot effectively reach this inflammatory source within the dense cartilage.

Cartilage Wear in Healthy and Osteoarthritis Joints

This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study.

The role of TGF-beta3 in cartilage development and osteoarthritis

Articular cartilage serves as a low-friction,load-bearing tissue without the support with blood vessels,lymphatics and nerves,making its repair a big challenge.Transforming growth factor-beta 3(TGF-β3),a vital member of the highly conserved TGF-βsuperfamily,plays a versatile role in cartilage physiology and pathology.TGF-β3 influences the whole life cycle of chondrocytes and mediates a series of cellular responses,including cell survival,proliferation,migration,and differentiation.Since TGF-β3 is involved in maintaining the balance between chondrogenic differentiation and chondrocyte hypertrophy,its regulatory role is especially important to cartilage development.Increased TGF-β3 plays a dual role:in healthy tissues,it can facilitate chondrocyte viability,but in osteoarthritic chondrocytes,it can accelerate the progression of disease.Recently,TGF-β3 has been recognized as a potential therapeutic target for osteoarthritis(OA)owing to its protective effect,which it confers by enhancing the recruitment of autologous mesenchymal stem cells(MSCs)to damaged cartilage.However,the biological mechanism of TGF-β3 action in cartilage development and OA is not well understood.In this review,we systematically summarize recent progress in the research on TGF-β3 in cartilage physiology and pathology,providing up-to-date strategies for cartilage repair and preventive treatment.

Inhibition of fibroblast activation protein ameliorates cartilage matrix degradation and osteoarthritis progression

Fibroblast activation protein(Fap)is a serine protease that degrades denatured type I collagen,α2-antiplasmin and FGF21.Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor and can be inhibited by the bone growth factor Osteolectin(Oln).Fap is also expressed in synovial fibroblasts and positively correlated with the severity of rheumatoid arthritis(RA).However,whether Fap plays a critical role in osteoarthritis(OA)remains poorly understood.Here,we found that Fap is significantly elevated in osteoarthritic synovium,while the genetic deletion or pharmacological inhibition of Fap significantly ameliorated posttraumatic OA in mice.Mechanistically,we found that Fap degrades denatured type II collagen(Col II)and Mmp13-cleaved native Col II.Intra-articular injection of r Fap significantly accelerated Col II degradation and OA progression.In contrast,Oln is expressed in the superficial layer of articular cartilage and is significantly downregulated in OA.Genetic deletion of Oln significantly exacerbated OA progression,which was partially rescued by Fap deletion or inhibition.Intra-articular injection of r Oln significantly ameliorated OA progression.Taken together,these findings identify Fap as a critical pathogenic factor in OA that could be targeted by both synthetic and endogenous inhibitors to ameliorate articular cartilage degradation.

Robotic in situ bioprinting for cartilage tissue engineering

Articular cartilage damage caused by trauma or degenerative pathologies such as osteoarthritis can result in significant pain,mobility issues,and disability.Current surgical treatments have a limited capacity for efficacious cartilage repair,and long-term patient outcomes are not satisfying.Three-dimensional bioprinting has been used to fabricate biochemical and biophysical environments that aim to recapitulate the native microenvironment and promote tissue regeneration.However,conventional in vitro bioprinting has limitations due to the challenges associated with the fabrication and implantation of bioprinted constructs and their integration with the native cartilage tissue.In situ bioprinting is a novel strategy to directly deliver bioinks to the desired anatomical site and has the potential to overcome major shortcomings associated with conventional bioprinting.In this review,we focus on the new frontier of robotic-assisted in situ bioprinting surgical systems for cartilage regeneration.We outline existing clinical approaches and the utilization of robotic-assisted surgical systems.Handheld and robotic-assisted in situ bioprinting techniques including minimally invasive and non-invasive approaches are defined and presented.Finally,we discuss the challenges and potential future perspectives of in situ bioprinting for cartilage applications.

Divergent chondro/osteogenic transduction laws of fibrocartilage stem cell drive temporomandibular joint osteoarthritis in growing mice

The anterior disc displacement(ADD)leads to temporomandibular joint osteoarthritis(TMJOA)and mandibular growth retardation in adolescents.To investigate the potential functional role of fibrocartilage stem cells(FCSCs)during the process,a surgical ADDTMJOA mouse model was established.From 1 week after model generation,ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis(OA)-like joint cartilage degeneration,manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis.Lineage tracing using Gli1^(-)CreER^(+);Tm^(fl/-)mice and Sox9-CreER^(+);Tm^(fl/-)mice showed that ADD interfered with the chondrogenic capacity of Gli1+FCSCs as well as osteogenic differentiation of Sox9+lineage,mainly in the middle zone of TMJ cartilage.Then,a surgically induced disc reposition(DR)mouse model was generated.The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice.And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment.In conclusion,ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage,resulting in cartilage degeneration and loss of subchondral bone homeostasis,finally causing TMJ growth retardation.DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Purifi cation and identification of anti-inflammatory peptides from sturgeon (Acipenser schrenckii) cartilage

Cartilage is a nonedible byproduct with little saleable value.However,previous studies have proposed the possibility of producing peptides from cartilage with immune function modulation potential.The current study aimed to investigate the potential anti-inflammatory activity of peptides derived from sturgeon(Acipenser schrenckii)cartilage in lipopolysaccharide(LPS)-stimulated RAW264.7 macrophages.Five peptide sequences,including four novel peptides,were identified from ethanol-soluble cartilage hydrolysates.Among these five peptides,LTGP,LLLE,LLEL and VGPAGPAGP reduced the production of nitric oxide(NO)and interleukin-6(IL-6)while increasing interleukin-10(IL-10)excretion.Transcriptome analysis suggested the inhibition of activated mitogen-activated protein kinase(MAPK)and interleukin-17(IL-17)signaling pathways after LLEL intervention.MAPK,which is involved in the IL-17 signaling pathway,was further proved to be blocked by downregulating the phosphorylation of p38,extracellular-signal regulated protein kinase(ERK),and c-jun N-terminal kinase(JNK).This novel peptide offers an attractive approach to develop functional foods.

Functionalized Hydrogels for Articular Cartilage Tissue Engineering

Articular cartilage(AC)is an avascular and flexible connective tissue located on the bone surface in the diarthrodial joints.AC defects are common in the knees of young and physically active individuals.Because of the lack of suitable tissue-engineered artificial matrices,current therapies for AC defects,espe-cially full-thickness AC defects and osteochondral interfaces,fail to replace or regenerate damaged carti-lage adequately.With rapid research and development advancements in AC tissue engineering(ACTE),functionalized hydrogels have emerged as promising cartilage matrix substitutes because of their favor-able biomechanical properties,water content,swelling ability,cytocompatibility,biodegradability,and lubricating behaviors.They can be rationally designed and conveniently tuned to simulate the extracel-lular matrix of cartilage.This article briefly introduces the composition,structure,and function of AC and its defects,followed by a comprehensive review of the exquisite(bio)design and(bio)fabrication of func-tionalized hydrogels for AC repair.Finally,we summarize the challenges encountered in functionalized hydrogel-based strategies for ACTE both in vivo and in vitro and the future directions for clinical translation.

Study on the Microstructure of Human Articular Cartilage/Bone Interface

For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope （SEM）, histological sections and MicroCT were used to observe, measure and model the micro- structure of cartilage/bone interface. The results showed that the cartilage/bone interface is in a hierarchical structure which is composed of four different tissue layers. The interlocking of hyaline cartilage and calcified cartilage and that of calcified car- tilage and subchondral bone are in the manner of＂protrusion-pore＂ with average diameter of 17.0 gm and 34.1 lam respectively. In addition, the cancellous bone under the cartilage is also formed by four layer hierarchical structure, and the adjacent layers are connected by bone trabecula in the shape of H, I and Y, forming a complex interwoven network structure. Finally, the simplified structure model of the cartilage/bone interface was proposed according to the natural articular cartilage/bone interface. The simplified model is a 4-layer gradient biomimetic structure, which corresponds to four different tissues of natural cartilage/bone interface. The results of this work would be beneficial to the design of bionic scaffold for the tissue engineering of articular cartilage/bone.

Thyroid Cartilage Chondrosarcoma Review: Management and Prognosis of a Rare Tumor

Objective: This article is a critical review of the literature concerning thyroid cartilage chondrosarcoma and is particularly focused on the management and prognosis of this rare entity. Study Design: A review of all the cases of thyroid cartilage chondrosarcoma reported in the literature up to January 2013. Methods: The search was carried out through the introduction of the MeSH terms: Chondrosarcoma, Laryngeal Cartilages, Thyroid Cartilage, Therapeutics. All the studies related to thyroid cartilage chondrosarcoma were selected together with a newly presented case. Results: A total of 47 cases have been described in the literature, and 35 of these include sufficient data for statistical analysis. The age of patients ranged from 40 to 77 years, with a male predilection (88.6%). The main symptoms were neck mass and hoarseness. Grade I and II tumors were most frequent. A total of 13 cases described an extension of the tumor beyond the thyroid cartilage. The most common treatment was partial laryngectomy (50%). All patients who died were male, with grade II or II-III tumor or associated sarcoma, had metastases and received radiotherapy in addition to total laryngectomy. Conclusion: Patient age and tumor size does not influence the prognosis. Tumor grade I and I-II have good prognoses, whereas the prognosis is unpredictable in tumors between grade II and III. Patients with associated sarcoma, or metastasis, have a worse prognosis. Partial laryngectomy is a good therapeutic option, although total laryngectomy is sometimes required in order to ensure complete resection.

Injectable hydrogels for cartilage and bone tissue engineering

Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix(ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.

Use of bone morphogenetic proteins in mesenchymal stemcell stimulation of cartilage and bone repair

The extracellular matrix-associated bone morphogenetic proteins(BMPs) govern a plethora of biological processes. The BMPs are members of the transforming growth factor-β protein superfamily, and they actively participate to kidney development, digit and limb formation, angiogenesis, tissue fibrosis and tumor development. Since their discovery, they have attracted attention for their fascinating perspectives in the regenerative medicine and tissue engineering fields. BMPs have been employed in many preclinical and clinical studies exploring their chondrogenic or osteoinductive potential in several animal model defects and in human diseases. During years of research in particular two BMPs, BMP2 and BMP7 have gained the podium for their use in the treatment of various cartilage and bone defects. In particular they have been recently approved for employment in non-union fractures as adjunct therapies. On the other hand, thanks to their potentialities in biomedical applications, there is a growing interest in studying the biology of mesenchymal stem cell(MSC), the rules underneath their differentiation abilities, and to test their true abilities in tissue engineering. In fact, the specific differentiation of MSCs into targeted celltype lineages for transplantation is a primary goal of the regenerative medicine. This review provides an overview on the current knowledge of BMP roles and signaling in MSC biology and differentiation capacities. In particular the article focuses on the potential clinical use of BMPs and MSCs concomitantly, in cartilage and bone tissue repair.

Mesenchymal stem cells as a potent cell source for articular cartilage regeneration

Since articular cartilage possesses only a weak capac-ity for repair, its regeneration potential is considered one of the most important challenges for orthopedic surgeons. The treatment options, such as marrow stimulation techniques, fail to induce a repair tissue with the same functional and mechanical properties of native hyaline cartilage. Osteochondral transplantation is considered an effective treatment option but is as-sociated with some disadvantages, including donor-site morbidity, tissue supply limitation, unsuitable mechani-cal properties and thickness of the obtained tissue. Although autologous chondrocyte implantation results in reasonable repair, it requires a two-step surgical pro-cedure. Moreover, chondrocytes expanded in culture gradually undergo dedifferentiation, so lose morpho-logical features and specialized functions. In the search for alternative cells, scientists have found mesenchymal stem cells(MSCs) to be an appropriate cellular mate-rial for articular cartilage repair. These cells were origi-nally isolated from bone marrow samples and further investigations have revealed the presence of the cells in many other tissues. Furthermore, chondrogenic dif-ferentiation is an inherent property of MSCs noticedat the time of the cell discovery. MSCs are known to exhibit homing potential to the damaged site at which they differentiate into the tissue cells or secrete a wide spectrum of bioactive factors with regenerative proper-ties. Moreover, these cells possess a considerable im-munomodulatory potential that make them the general donor for therapeutic applications. All of these topics will be discussed in this review.

Recent advances in cell sheet technology for bone and cartilage regeneration: from preparation to application

Bone defects caused by trauma,tumour resection,infection and congenital deformities,together with articular cartilage defects and cartilage–subchondral bone complex defects caused by trauma and degenerative diseases,remain great challenges for clinicians.Novel strategies utilising cell sheet technology to enhance bone and cartilage regeneration are being developed.The cell sheet technology has shown great clinical potential in regenerative medicine due to its effective preservation of cell–cell connections and extracellular matrix and its scaffold-free nature.This review will first introduce several widely used cell sheet preparation systems,including traditional approaches and recent improvements,as well as their advantages and shortcomings.Recent advances in utilising cell sheet technology to regenerate bone or cartilage defects and bone–cartilage complex defects will be reviewed.The key challenges and future research directions for the application of cell sheet technology in bone and cartilage regeneration will also be discussed.

Cartilage repair techniques of the talus: An update

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients.Although their pathomechanism is well understood,it is well known that different aetiologic factors play a role in their origin.Additionally,it is well recognised that the talar articular cartilage strongly differs from that in the knee.Despite this fact,many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee.Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans.However,depending on the size of the lesions,surgical approaches are necessary to treat many of these defects.Bone marrow stimulation techniques may achieve good results in small lesions.Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation.Autologous chondrocyte transplantation,as a restorative procedure,is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor.The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.

Benefits of Ilizarov automated bone distraction for nerves and articular cartilage in experimental leg lengthening

AIM To determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage.METHODS Twenty-nine dogs were divided in two experimental groups: Group M-leg lengthening with manual distraction(1 mm/d in 4 steps), Group A-automated distraction(1 mm/d in 60 steps) and intact group. Animals were euthanized at the end of distraction, at 30 th day of fixation in apparatus and 30 d after the fixator removal. M-responses in gastrocnemius and tibialis anterior muscles were recorded, numerical histology of peronealand tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed.RESULTS Better restoration of M-response amplitudes in leg muscles was noted in A-group. Fibrosis of epineurium with adipocytes loss in peroneal nerve, subperineurial edema and fibrosis of endoneurium in some fascicles of both nerves were noted only in M-group, shares of nerve fibers with atrophic and degenerative changes were bigger in M-group than in A-group. At the end of experiment morphometric parameters of nerve fibers in peroneal nerve were comparable with intact nerve only in A-group. Quantitative parameters of articular cartilage(thickness, volumetric densities of chondrocytes, percentages of isogenic clusters and empty cellular lacunas, contents of sulfur and calcium) were badly changed in M-group and less changed in A-group.CONCLUSION Automated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.