Cartilage Deformation Research Articles

Zonal Characteristics of Collagen Ultrastructure and Responses to Mechanical Loading in Articular Cartilage.

The biomechanical properties of articular cartilage arise from a complex bioenvironment comprising hierarchically organised collagen networks within the extracellular matrix (ECM) that interact with the proteoglycan-rich interstitial fluid. This network features a depth-dependent fibril organisation across different zones. Understanding how collagen fibrils respond to external loading is key to elucidating the mechanisms behind lesion and managing degenerative conditions like osteoarthritis. This study employs polarisation-resolved second harmonic generation (pSHG) microscopy to quantify the ultrastructural organisation of collagen fibrils and their spatial gradient along the depth of bone-cartilage explants at a close-to-in vivo condition. By combining with in-situ loading, we examined the responses of collagen fibrils by quantifying changes in their principal orientation and degree of alignment. The spatial gradient and heterogeneity of collagen organisation were captured at high resolution (1 µm) along the longitudinal plane of explants (0.5 by 2 mm). Zone-specific ultrastructural characteristics were quantified to aid in defining zonal borders, revealing consistent zonal proportions with varying overall thicknesses. Under compression, the transitional zone exhibited the most significant re-organisation of collagen fibrils. It initially allowed large deformation through re-orientation of fibrils, which then tightened fibril alignment to prevent excessive deformation, indicating a dynamic adaptation mechanism in response to increasing strain levels. Our results provide comprehensive, zone-specific baselines of cartilage ultrastructure and micromechanics, crucial for investigating the onset and progression of degenerative conditions, setting therapeutic intervention targets, and guiding cartilage repair and regeneration efforts. STATEMENT OF SIGNIFICANCE: Achieved unprecedented quantification of the spatial gradient and heterogeneity of collagen ultrastructural organisation at a high resolution (1 µm) along the full depth of the longitudinal plane of osteochondral explants (500 by 2000 µm) in close-to-in vivo condition. Suggested new anatomical landmarks based on ultrastructural features for determining zonal borders and found consistent zonal proportions in explants with different overall thicknesses. Demonstrated that collagen fibrils initially respond by re-orientating themselves at low strain levels, playing a significant role in cartilage deformation, particularly within the transitional zone. At higher strain levels, more collagen fibrils changed their alignment, indicating a dynamic shift in the response mechanism at varying strain levels.

Experimental Investigation of the Effect of Polydioxanone Plate and Platelet-Rich Plasma on Cartilage Regeneration.

Objectives: This study aimed to investigate the effectiveness of polydioxanone (PDS) plate and platelet-rich plasma (PRP) on the regeneration of cartilage grafts, which are frequently used in nasal and septal surgery. Methods: Fifteen white New Zealand Albino-type female rabbits were used in the study. Our study was carried out on 4 different applications on each animal: cartilage only, cartilage+PRP, cartilage+PDS plate, and cartilage+PRP+PDS plate, and in 3 different periods: the first month, the second month, and the third month. Results: A significant difference was obtained between the groups using cartilage+PRP and cartilage+PRP+PDS only in the first month. When both application types were compared, a statistically significant decrease was found in the histopathological cartilage viability score after PDS use. In examining peripheral chondrocyte proliferation, a statistically significant difference was found only in the third-month comparison. When the group using only cartilage was compared with the group using cartilage+PDS, it was determined that peripheral chondrocyte proliferation was significantly reduced at the end of the third month with PDS. In evaluating fibrosis and foreign body reaction, a statistically significant increase was detected using a PDS plate. In histopathological cartilage viability score statistical analysis, a significant difference was obtained between the groups using cartilage+PRP and cartilage+PRP+PDS only in the first month. Degeneration in the cartilage structure was observed macroscopically in the specimens where the PDS plate was used. Shape change and cartilage deformation were observed in the PDS plate specimens. Conclusions: When the results were examined, this observation coincided with the statistically significant increase in foreign body reaction and fibrosis in the PDS plate groups. However, these results contradicted our hypothesis before the study and the information in the literature. Our results will help provide preliminary information and guidance for future studies and offer a different perspective.

Characteristics and Outcomes of Surgical Treatment for Anterolateral Ankle Impingement Due to the Distal Fascicle of the Anterior Inferior Tibiofibular Ligament.

The pathomechanism of anterolateral ankle impingement (ALAI) due to the distal fascicle of the anterior inferior tibiofibular ligament (DF-AITFL) has not been fully elucidated. In addition, because of its rarity, no definitive diagnostic criteria have been established for ALAI due to DF-AITFL. To document the symptom characteristics and magnetic resonance imaging (MRI) and and arthroscopic findings as well as postoperative clinical outcomes of ALAI due to DF-AITFL. Case series; Level of evidence, 4. Included were 12 patients (5 male and 7 female; mean age, 34.4 years [range, 21-76 years]) who were diagnosed with ALAI due to DF-AITFL and underwent excision of the DF-AITFL from November 2017 to August 2021. Symptom characteristics and symptom-related medical histories were evaluated, as were MRI and arthroscopic findings. Clinical outcomes were assessed using the visual analog scale for pain, American Orthopaedic Foot & Ankle Society ankle-hindfoot functional scale, and Foot Function Index. All 12 patients had a history of ankle sprain before symptom onset. DF-AITFL was confirmed by MRI in all patients. Bone edema of the talus was observed in 2 patients (16.7%), and cartilage abnormalities in 3 patients (25%). Arthroscopy showed that the DF-AITFL contacted the anterolateral aspect of the talar dome during range of motion in all patients and that the AITFL was bent where it contacted the anterolateral dome of the talus in 3 patients (25%). Partial tear or adhesion of the DF-AITFL was noted in 7 patients (58.3%), and cartilage deformation at the anterolateral talar dome in 4 patients (33.3%). Mean visual analog scale pain, American Orthopaedic Foot & Ankle Society, and Foot Function Index scores improved significantly from preoperatively to postoperatively. ALAI due to DF-AITFL should be considered a possible cause of anterolateral ankle pain after an ankle sprain. The diagnosis can be reliably made with a thorough clinical examination and imaging studies. Half of the patients in this series also had lateral ankle instability. Surgical resection of the DF-AITFL and ligament reconstruction, if necessary, resulted in significant symptom improvement.

Characteristics of Anterolateral Ankle Impingement Due to a Distal Fascicle of Anterior Inferior Tibiofibular Ligament

Category: Arthroscopy; Ankle Introduction/Purpose: The pathomechanism of anterolateral ankle impingement (ALAI) due to a distal fascicle of the anterior inferior tibiofibular ligament (DF-AITFL) has not been fully elucidated. In addition, due to its rarity, no definitive diagnostic criteria have been established for ALAI by DF-AITFL. This study was performed to document the symptom characteristics, MRI and arthroscopic findings, and postoperative clinical outcomes of ALAI due to a DF-AITFL. Methods: Twelve patients (5 males and 7 females of mean age 34.4 years (range 21-76 years)) diagnosed with ALAI due to DF-AITFL from November 2017 to August 2021 and treated surgically were included in this study. Symptom characteristics and symptom-related medical histories were evaluated. Clinical outcomes were assessed using a visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scale, and foot function index (FFI). In addition, magnetic resonance imaging (MRI) and arthroscopic findings were evaluated. Results: All 12 patients had a history of ankle sprain prior to symptom onset. Mean VAS, AOFAS ankle-hindfoot functional scale, and FFI improved significantly postoperatively. DF-AITFL was confirmed by MRI in all cases (Fig. 1). Bone edema of the talus was observed in two cases (16.7%), and cartilage abnormalities in three (25%). Arthroscopy showed that the DF-AITFL contacted the anterolateral aspect of the talar dome during ROM in all cases and that the AITFL was bent where it contacted the anterolateral dome of the talus in 3 cases (25%). Partial tear or adhesion of the DF-AITFLwas noted in seven cases (58.3%), and cartilage deformation at the anterolateral talar dome in 4 cases (33.3%). Conclusion: ALAI due to DF-AITFL should be considered a possible cause of anterolateral ankle pain, especially in cases of ankle sprain. Figure 1. (A) The coronal oblique plane was prescribed for the DF-AITFL (arrow) using standard axial planes parallel to the AITFL (arrowhead). (B) The axial oblique plane was prescribed using coronal oblique planes parallel to the AITFL. The DF-AITFL was in contact with the anterolateral dome of the talus. Abnormal findings, including bone edema (asterisk) (C) and cartilage abnormalities (circle) (D) related to DF-AITFL were evaluated by MRI.

Bat Ear Correction Steps and Outcomes for Better Life Support.

An unusually projecting human ear is known as a prominent ear, otapostasis, or bat ear. It might be both bilateral and unilateral. The scapha and antihelix of the big concha are not well formed. It is the outcome of cartilage deformity that occurred during early ear development in utero. After the child reaches five years old, the abnormality can be corrected at any time. In order to prevent psychological suffering, the procedure should ideally be performed as soon as possible. Otoplasty correction is reshaping the ear cartilage to bring the ear closer to the side of the head. The cartilage is reshaped, but the skin is left in place. Hearing remains unaffected by the operation. It is mainly done for aesthetic reasons. Although they are uncommon, the post-operative consequences from the operation include hematoma development, keloid formation, infection, and asymmetry in the ears. Otoplasty is a cosmetic operation that involves permanent sutures to alter the size, shape, or location of the ear. The main purpose of otoplasty is to treat promin auris, or bulging ears. Promin auris, the principal indication for otoplasty, is the subject of this review. The indications, contraindications, and method utilized in otoplasty are reviewed in this exercise, which also emphasizes the need of pre- and post-operative care for patients having this surgery. Otoplasty results are generally lifelong and will improve the self-confidence. The goals of otoplasties are to make the ears appear more natural in comparison to the head and help with the overall contour of the ears. Final ear surgery results will be visible after a two week recovery period, with small improvements appearing for up to 12 months post-procedure. A proper understanding of the diagnosis, indications, and surgical techniques will lead to positive outcomes in otoplasty.

Recent developments in computational modelling of the knee

ObjectiveModel calculations of knee joint loading range from an assumption of perfectly rigid articular surfaces to more realistic simulations of cartilage and meniscal deformation. Rigid-body musculoskeletal models simulate knee contact mechanics using the ‘bed of springs’ method from elastic foundation theory whereas finite-element models discretise each structure into a series of interconnected elements and ascribe material properties to each element. This mini-review describes some of the most recent developments in computational modelling of knee contact mechanics and suggests possible avenues for future improvements. DesignNarrative mini-review. ResultsMuscle and joint contact forces can be calculated synchronously at a reasonable computational cost (typically a few hours of CPU time) using rigid-body models and elastic foundation theory whereas similar calculations using fully deformable finite-element models can take several days and even weeks. The main computational expense incurred in finite-element musculoskeletal modelling is the solution of a muscle-force optimization problem. ConclusionCalculation of muscle and joint contact forces within the framework of a finite-element musculoskeletal model remains challenging. Integrating biomechanical data from human motion experiments with fully deformable finite-element models to simulate knee contact mechanics during dynamic activity is an evolving science. Future work should explore the use of efficient methods such as direct collocation to perform muscle-driven dynamic optimization simulations of movement using finite-element musculoskeletal models. Dynamic optimization may be combined with finite-element modelling to enable predictive simulations of movement so that the effects of changes in musculoskeletal anatomy on knee contact mechanics can be studied more systematically.

Relationships Between Running Biomechanics and Femoral Articular Cartilage Thickness and Composition in Anterior Cruciate Ligament Reconstruction Patients.

Although individuals with anterior cruciate ligament reconstruction (ACLR) are at high risk for posttraumatic osteoarthritis, mechanisms underlying the relationship between running and knee cartilage health remain unclear. We aimed to investigate how 30 min of running influences femoral cartilage thickness and composition and their relationships with running biomechanics in patients with ACLR and controls. Twenty patients with ACLR (time post-ACLR: 14.6 ± 6.1 months) and 20 matched controls participated in the study. A running session required both groups to run for 30 min at a self-selected speed. Before and after running, we measured femoral cartilage thickness via ultrasound imaging. A MRI session consisted of T2 mapping. The ACLR group showed longer T2 relaxation times in the medial femoral condyle at resting compared with the control group (central: 51.2 ± 16.6 vs. 34.9 ± 13.2 ms, p = 0.006; posterior: 50.2 ± 10.1 vs. 39.8 ± 7.4 ms, p = 0.006). Following the run, the ACLR group showed greater deformation in the medial femoral cartilage than the control group (0.03 ± 0.01 vs. 0.01 ± 0.01 cm, p = 0.001). Additionally, the ACLR group showed significant negative correlations between resting T2 relaxation time in the medial femoral condyle and vertical impulse (standardized regression coefficients = -0.99 and p = 0.004) during running. Our findings suggest that those who are between 6 and 24 months post-ACLR have degraded cartilage composition and their cartilage deforms more due to running vGRF.

In vivo human knee varus-valgus loading apparatus for analysis of MRI-based intratissue strain and relaxometry

The diagnosis of early-stage osteoarthritis remains as an unmet challenge in medicine and a roadblock to evaluating the efficacy of disease-modifying treatments. Recent studies demonstrate that unique patterns of intratissue cartilage deformation under cyclic loading can serve as potential biomarkers to detect early disease pathogenesis. However, a workflow to obtain deformation, strain maps, and quantitative MRI metrics due to the loading of articular cartilage in vivo has not been fully developed. In this study, we characterize and demonstrate an apparatus that is capable of applying a varus-valgus load to the human knee in vivo within an MRI environment to enable the measurement of cartilage structure and mechanical function. The apparatus was first tested in a lab environment, then the functionality and utility of the apparatus were examined during varus loading in a clinical 3T MRI system for human imaging. We found that the device enables quantitative MRI metrics for biomechanics and relaxometry data acquisition during joint loading leading to compression of the medial knee compartment. Integration with spiral DENSE MRI during cyclic loading provided time-dependent displacement and strain maps within the tibiofemoral cartilage. The results from these procedures demonstrate that the performance of this loading apparatus meets the design criteria and enables a simple and practical workflow for future studies of clinical cohorts, and the identification and validation of imaging-based biomechanical biomarkers.

Mid-term results of autologous matrix-induced chondrogenesis for large chondral defects in hips with femoroacetabular impingement syndrome.

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI). This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm2, who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain. A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (rs = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs. Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials.

Further Refinements in Otoplasty Surgery: A Modified Approach to Prevent Suture Extrusion in Cartilage-Suturing Otoplasty Using a Postauricular Dermofascial Flap.

Suture extrusion has been reported to be the most common complication after cartilage-sparing otoplasty. Several studies have described various designs of postauricular flaps to cover the cartilage sutures and reduce the incidence of suture extrusion. A total of 100 consecutive patients with prominent ears were operated on between January of 2018 and February of 2023 using a deepithelialized postauricular dermofascial flap that is performed as an adjunct to the authors' cartilage-sparing otoplasty technique, which is essentially a combined modified Mustardé and Furnas technique. The flap is used to cover the cartilage-holding sutures with an extra layer of vascularized tissue to avoid the scar being directly over these sutures. The median age of patients was 12 years (interquartile range, 9 to 15). One out of the 100 patients (1%) developed a postauricular skin infection requiring surgical removal of sutures. Primary suture extrusion did not occur; in an earlier study of cartilage-sparing technique without the postauricular flap, 17 out of 200 patients had suture extrusion ( P = 0.001). No hematoma occurred that necessitated return to the theater. Skin necrosis and wound dehiscence did not occur in any case. No patient developed cartilage deformities or relapse requiring surgical correction. Combining cartilage-sparing otoplasty using sutures and the described postauricular dermofascial flap is simple to perform and has significantly reduced the complication rate and improved the outcome compared with cartilage-sparing otoplasty alone. This flap is recommended for both primary and revisional otoplasty. Therapeutic, IV.

Experimental Ultrasound Approach for Studying Knee Intra-Articular Femur-Tibia Movements under Different Loads.

The purpose of the present study was to develop an experimental model for the study of intra-articular knee movements depending on the function of the knee joint and involved muscle groups under isometric stretching conditions with different loads. The experimental procedure included an ultrasound examination of a knee joint after isometric stretching in healthy men (n = 32). The changes (in millimeters) in the distances between the femur and tibia were measured using an ultrasound sonographer at three stages. The first stage was performed on ten (n = 10) healthy men in five different sitting and upright positions. In the second and third experimental model stages, lower limbs loading was applied to 22 participants. Our hypothesis, which was confirmed, was that as a result of increased loads on the participant's back, an intra-articular decrease in the femur-tibia cartilage surface distance would be observed. The accuracy of the created experimental model was improved over its three stages from 30% to 9%. Quantitative model data can help to create a mathematical model of the mechanical effects during the deformation of knee joint bone cartilage and it can also help outline some future tasks: increasing loading weights, enlarging participant groups, performing comparisons of men and women, and performing comparisons of healthy and pathological individuals.

Synergetic support of cartilage homeostasis via coupled thermal-pressure stimuli: a transcriptomic study in human cartilage explants

During daily activities, cartilage encounters complex biophysical cues upon loading. Foremost among these is the coupled stimulation of hydrostatic pressure (HP) and loading-induced temperature increase (T), which encompasses both mechanical and thermal aspects of biophysical stimulations in cartilage. While prior research on this subject has been initiated in our laboratory, the detailed mechanisms of combined HP-T effects on chondrocytes in their natural environment remain largely unexplored. Using a custom bioreactor, we applied both isolated and combined HP-T stimuli to cartilage explants obtained from a non-inflammatory adolescent knee joint. Tissue and cellular responses were evaluated through histochemical staining and transcriptomic analyses, employing bulk RNA-sequencing complemented with signaling enrichment analyses. Our findings reveal that the thermal component of the coupled HP-T stimulation predominantly regulates the chondrocytes’ transcriptional profile during the stimulation period. When coupled with HP stimulation, a peak in chondroinduction was observed. This coupling process notably boosted chondroprotection in a synergistic manner, as demonstrated by the corresponding enhanced negative regulation of apoptotic processes and increased levels of Heat Shock Protein 70 (HSPA). Our study suggests that the upregulation in protein translation and processing, triggered by thermal stimulation, may serve as an adaptive mechanism in chondrocytes to mechanical simulations, thereby contributing to the observed synergy during the coupling of these two biophysical stimuli. The results highlight the potential of integrating thermal stimulation, a natural accompanying process during cartilage deformation, in tissue engineering, cell therapy or physiotherapy.

Cartilage deformation following a walking bout in individuals with anterior cruciate ligament reconstruction.

The purpose was to (1) compare the effect of a walking bout on femoral cartilage deformation between limbs with and without anterior cruciate ligament reconstruction (ACLR) and (2) examine the association between gait kinetics and the magnitude of cartilage deformation. A total of 30 individuals with primary unilateral ACLR completed this study [14 male, 16 female; age = 22.57 (3.78) years; body mass index (BMI) = 25.88 (5.68) kg/m2 ; time since ACLR = 61.00 (16.43) months]. Overground walking biomechanics were assessed on day 1, and a 30-min walking bout or 30-min resting bout (control) were completed on days 2 and 3 (counterbalanced order). Femoral cartilage thickness was measured using ultrasound before, immediately following, and 30-min following each intervention. Linear mixed effects models compared the effect of walking on cartilage thickness between the ACLR and contralateral limbs after adjusting for sex, BMI, speed, and the number of steps. Stepwise regression examined the association between the external knee flexion and adduction moments and cartilage deformation following walking. There was a significant limb × time interaction for medial cartilage thickness. Post hoc analyses indicated that cartilage thickness decreased immediately following walking in the contralateral but not ACLR limb. Main effects of limb were observed for medial, central, and lateral cartilage thickness indicating thicker cartilage in the ACLR compared with contralateral limb. A higher knee adduction moment was associated with greater cartilage deformation in the ACLR limb. Femoral cartilage in the ACLR limb exhibited a less dynamic response to walking than the uninvolved limb, which may be due to habitual underloading during gait.

Порівняльний аналіз напружено-деформованого стану грудної клітки при корекції лійкоподібної деформації із застосуванням двох пластин: порівняння паралельного та схрещеного методів встановлення фіксаторів

Minimally invasive correction of funnel-shaped chest deformity by the Nuss is an effective and cosmetic method of surgical correction of this deformity. Some authors have proposed the use of two plates with a crossed technique for correction. Purpose - to study the changes that occur in the stressed-deformed state of the chest model in comparison of the parallel crossed arrangement of the fixators during the minimally invasive correction of funnel-shaped chest deformity according to Nuss. Materials and methods. 2 schemes for the correction of the funnel-shaped deformation of the sternum were modeled: with a parallel arrangement of plates (parallel method), with a cross-shaped arrangement of plates (crossed method). The models were loaded with a distributed force of 100 N applied to the sternum. They studied the stress values in the bone elements, the relative deformations of costal cartilage, as the softest and, as a result, the most favorable to deformation element of the models. The magnitudes of the maximum movements of the sternum and corrective plates were also studied as an indicator of the preservation of the achieved correction. Results. The crossed method of positioning the corrective plates ensures a slightly lower level of stress in almost all bone elements. An exception can be considered the seventh ribs, where the stress, in this case, reaches 9.0 MPa, which is close to the lower limit of the indicators of the strength limit of the ribs. From the point of view of preserving deformation correction, the crossed method of arranging the correcting plates has a slight advantage of 1.0 mm. But the parallel scheme provides a smaller relative deformation of the costal cartilages. Taking into account all of the above, it can be concluded that none of the studied schemes has an unequivocal advantage over the other according to the criteria of mechanical indicators. Therefore, when choosing one or another scheme for the correction of a funnel-shaped sternum deformity, additional information should be taken into account, such as the shape of the sternum deformity and the rib, the convenience of carrying out the plates, the age of the patient, etc. Conclusions. None of the studied schemes has an unequivocal advantage over the other according to the criteria of mechanical indicators. From the point of view of preserving deformation correction, the crossed method of arranging the correcting plates has a slight advantage of 1.0 mm. The parallel scheme ensures a smaller relative deformation of the costal cartilages. According to the criterion of stress distribution in the bone elements of the model, the crossed method of arranging the corrective plates provides a slightly lower level in almost all bone elements, but the maximum stress value of 9.0 MPa on the seventh rib with the cross-shaped arrangement of the corrective plates approaches the lower limit of the index of the strength limit of the ribs which, in some cases, can cause its fracture. Additional information should be taken into account when choosing one or another scheme for the correction of the funnel-shaped deformity of the sternum. No conflict of interests was declared by the authors.

Exposure to Butylparaben Induces Craniofacial Bone Developmental Toxicity in Zebrafish (Danio rerio) Embryos

Butylparaben (BuP) is a common antibacterial preservative utilized extensively in food, medical supplies, cosmetics, and personal care products. The current study reports the use of Zebrafish (Danio rerio) embryos to investigate potential developmental toxicity caused by exposure to BuP. The development of Neural crest cells (NCCs) is highly active during gastrulation in Zebrafish embryos. Thus, we utilized 0.5 mg/L, 0.75 mg/L, and 1 mg/L BuP solutions, respectively, in accordance with the international safety standard dosage. We observed severe craniofacial cartilage deformities, periocular edema, cardiac dysplasia, and delayed otolith development in the Zebrafish larvae 5 days after exposure. The oxidative stress response was significantly enhanced. In addition, the biochemical analysis revealed that the activities of catalase (CAT) and superoxide dismutase (SOD) were significantly reduced relative to the control group, whereas the concentration of malondialdehyde (MDA) was significantly elevated. Furthermore, ALP activity, a marker of osteoblast activity, was also reduced. Moreover, the RT-qPCR results indicated that the expression of chondrocyte marker genes sox9a, sox9b, and col2a1a was down-regulated. In addition, the morphology of maxillofacial chondrocytes was altered in Zebrafish larvae, and the proliferation of cranial NCCs was inhibited. Accordingly, our findings indicate that strong oxidative stress induced by BuP inhibits the proliferation of NCCs in larval Zebrafish, leading to craniofacial deformities.

Red blood cell - Platelet ratio (RPR) and Hemoglobin - Platelet ratio (HPR) in patients with rheumatoid arthritis: a study at Hue University of Medicine and Pharmacy Hospital

ABSTRACT Background: Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints, resulting in destruction and deformation of bones and cartilage. In addition to causing joint damage, up to 30 - 70% of RA patients have chronic anemia that reduces quality of life. The inflammatory process affects some red blood cell and platelet indices such as increased platelet count, anemia and hypochromic microcytic cells. Red blood cell - platelet ratio (RPR) and hemoglobin - platelet ratio (HPR) are considered as indicators to help assess inflammation and activity level in patients with RA. This study describes hematological characteristics and the relationship of RPR and HPR indices with inflammation in patients with RA. Methods: The study was conducted on 30 patients with RA at the Department of General Internal Medicine - Endocrinology - Musculoskeletal and a control group of 30 healthy people who came to hospital of Hue University of Medicine and Pharmacy from April 2023 to August 2023. Results: Both RPR and HPR indices in the disease group were statistically significant lower than the control group (p < 0.001). The predictive value of rheumatoid arthritis of RPR and HPR with cutoff points of 0.016 and 0.455 respectively (p < 0.05). The RPR index was strongly positively correlated with HPR (p < 0.001). PLT was strongly negatively correlated with RPR (p < 0.001) and HPR (p < 0.001). Conclusion: The RPR and HPR indices in RA patients were lower than those in controls, and could be one of the indicators to help assess inflammation in patients.

Study on the influence of buried thread nasal augmentation on dorsal soft tissue of nose and revision rhinoplasty

To investigate the influence of buried thread nasal augmentation on dorsal soft tissue of nose and revision rhinoplasty. A clinical data of 29 patients requesting revision rhinoplasty after buried thread nasal augmentation, who were admitted between July 2017 and July 2019 and met the selection criteria, was retrospectively analyzed. All patients were female with an average age of 26.8 years (range, 18-43 years). The patiens were admitted to the hospital at 3-48 months after buried thread nasal augmentation (median, 15 months). Among them, there were 18 cases of insufficient nasal tip projection, 22 cases of insufficient nasal root projection, 7 cases of threads ectasia, 5 cases of threads exposure, 3 cases of infection, and 10 cases with two or more conditions. There were 9 cases of combined short nose deformity, 1 case of spherical hypertrophy of the nasal tip, 3 cases of deviation of the nasal columella, 3 cases of excessive width of the nasal base, and 1 case of nasal hump. Three infected patients only underwent threads removal and debridement. The rest patients underwent revision rhinoplasty, and the dorsum of the nose was made with polytetrafluoroethylene expansion; the tip of the nose was reshaped by taking autologous rib cartilage and alar cartilage in 16 cases, and by taking autologous septal cartilage and alar cartilage in another 10 cases. The threads and surrounding tissue specimens removed during operation were subjected to histologic observation. Nasal length and nasal tip projection were measured after revision rhinoplasty and the ratio was calculated to evaluate the nasal morphology; patient satisfaction was evaluated using the Likert 5-grade scale. Patients were followed up 12-48 months (mean, 18 months). Inflammation was controlled in 3 patients with infections caused by buried thread nasal augmentation. The remaining 26 patients had satisfactory results immediately after revision rhinoplasty. Before revision rhinoplasty and at 7 days and 6 months after revision rhinoplasty, the nasal length was (4.11±0.34), (4.36±0.25), and (4.33±0.22) cm, respectively; the nasal tip projection was (2.34±0.25), (2.81±0.18), and (2.76±0.15) cm, respectively; and the nasal tip projection/nasal length ratio was 0.57±0.08, 0.65±0.05, and 0.64±0.04, respectively. There were significant differences in the nasal length and the nasal tip projection between time points ( P<0.05). There was a significant difference in the nasal tip projection/nasal length ratio between pre- and post-operation ( P<0.05), but there was no significant difference between 7 days and 6 months after operation ( P>0.05). The Likert score for satisfaction ranged from 1.5 to 5.0 (mean, 4.05). During follow-up period of 26 patients, no nasal prosthesis was exposed, and the shape of the nose was stable, and the nasal skin of 5 patients with exposed threads could be seen with different degrees of scarring; there was no infection, cartilage resorption, and no cartilage deformation, displacement, or exposure. Histological observation showed that absorbable threads were not only absorbed after implantation, but also with the prolongation of time, the inflammatory changes in the surrounding tissues caused by decomposition and absorption of the threads showed a gradual aggravation of the first, the heaviest inflammatory reaction in 6 to 12 months, and then gradually reduce the trend. After implantation of the absorbable thread into the subcutaneous tissue of the nasal dorsum, the nature of the thread is different from the body's own tissue, which will affect the soft tissue compliance of the nasal dorsum. The degradation and absorption of the thread will stimulate the infiltration of inflammatory cells and the proliferation of fibroblasts in the surrounding tissue and then form scar tissue, which will affect the design and effect of revision rhinoplasty.

Time-Resolved Quantification of Patellofemoral Cartilage Deformation in Response to Loading and Unloading via Dynamic MRI With Prospective Motion Correction.

In vivo cartilage deformation has been studied by static magnetic resonance imaging (MRI) with in situ loading, but knowledge about strain dynamics after load onset and release is scarce. To measure the dynamics of patellofemoral cartilage deformation and recovery in response to in situ loading and unloading by using MRI with prospective motion correction. Prospective. Ten healthy male volunteers (age: [31.4 ± 3.2] years). T1-weighted RF-spoiled 2D gradient-echo sequence with a golden angle radial acquisition scheme, augmented with prospective motion correction, at 3 T. In situ knee loading was realized with a flexion angle of approximately 40° using an MR-compatible pneumatic loading device. The loading paradigm consisted of 2 minutes of unloaded baseline followed by a 5-minute loading bout with 50% body weight and an unloading period of 38 minutes. The cartilage strain was assessed as the mean distance between patellar and femoral bone-cartilage interfaces as a percentage of the initial (pre-load) distance. Wilcoxon signed-rank tests (significance level: P < 0.05), Pearson correlation coefficient (r). The cartilage compression and recovery behavior was characterized by a viscoelastic response. The elastic compression ([-12.5 ± 3.1]%) was significantly larger than the viscous compression ([-7.6 ± 1.5]%) and the elastic recovery ([10.5 ± 2.1]%) was significantly larger than the viscous recovery ([6.1 ± 1.8]%). There was a significant residual offset strain ([-3.6 ± 2.3]%) across the cohort. A significant negative correlation between elastic compression and elastic recovery was observed (r = -0.75). The in vivo cartilage compression and recovery time course in response to loading was successfully measured via dynamic MRI with prospective motion correction. The clinical relevance of the strain characteristics needs to be assessed in larger subject and patient cohorts. 2 TECHNICAL EFFICACY: Stage 1.

A Scarless Method for Correcting Tanzer Group IIB-Constricted Ear Without Cartilage Grafting.

Tanzer group IIB-constricted ear is described as a deformity of the helix, antihelix, or scapha. Deficiency of the auricular skin and cartilage is a key point in the reconstruction of the cartilaginous framework. Traditionally, the treatment of a constricted ear mainly includes 2 aspects: correction of cartilage deformity and restoration of skin volume deficiency. By mimicking the suspension principle of a cable bridge, our technique only requires adjustment of the spatial directions and mechanical forces between the 2 flaps to achieve an aesthetic effect. The authors were able to avoid harvesting the costal cartilage. The desired ear shape was obtained immediately postoperatively. Therefore, Vaseline gauze was not applied and was modeled along the scapha and antihelix. Expansion of the ear was remarkable in both horizontal and vertical lengths. Our technique causes less damage, less scarring, shorter operation time, fewer complications, faster rehabilitation, and no delays.

The Promise of Regenerative Medicine in the Reconstruction of Auricular Cartilage Deformities.

There are many physiologic and psychologic challenges associated with ear cartilage deformities which are incredibly distasteful to patients, particularly children. The development of regenerative medicine (RM) sciences has opened up a new window for the reconstruction of auricular cartilage because it allows the creation of a structure similar to the auricular in appearance and function. As part of this review, we discuss the role that each RM tool, including tissue engineering, cells, and biomolecules, plays in developing engineered auricular tissue. In previous studies, it was shown that the simultaneous use of natural and synthetic biomaterials as well as three-dimensional printing techniques could improve the biological and mechanical properties of this tissue. Another critical issue is using stem cells and differentiated cartilage cells to produce tissue-specific cellular structures and extracellular matrix. Also, the importance of choosing a suitable animal model in terms of handling and care facilities, physiologic similarities to humans, and breed uniformity in the preclinical assessments have been highlighted. Then, the clinical trials registered on the clinicaltrials.gov website, and the commercialized product, called AuriNovo, have been comprehensively explained. Overall, it is important to provide engineered auricular cartilage structures with acceptable safety and efficacy compared with standard methods, autologous cartilage transplantation, and prosthetic reconstruction in RM.