Features Of Knee Osteoarthritis Research Articles

XGBoost-SHAP-based interpretable diagnostic framework for knee osteoarthritis: a population-based retrospective cohort study

ObjectiveTo use routine demographic and clinical data to develop an interpretable individual-level machine learning (ML) model to diagnose knee osteoarthritis (KOA) and to identify highly ranked features.MethodsIn this retrospective, population-based cohort study, anonymized questionnaire data was retrieved from the Wu Chuan KOA Study, Inner Mongolia, China. After feature selections, participants were divided in a 7:3 ratio into training and test sets. Class balancing was applied to the training set for data augmentation. Four ML classifiers were compared by cross-validation within the training set and their performance was further analyzed with an unseen test set. Classifications were evaluated using sensitivity, specificity, positive predictive value, negative predictive value, accuracy, area under the curve(AUC), G-means, and F1 scores. The best model was explained using Shapley values to extract highly ranked features.ResultsA total of 1188 participants were investigated in this study, among whom 26.3% were diagnosed with KOA. Comparatively, XGBoost with Boruta exhibited the highest classification performance among the four models, with an AUC of 0.758, G-means of 0.800, and F1 scores of 0.703. The SHAP method reveals the top 17 features of KOA according to the importance ranking, and the average of the experience of joint pain was recognized as the most important features.ConclusionsOur study highlights the usefulness of machine learning in unveiling important factors that influence the diagnosis of KOA to guide new prevention strategies. Further work is needed to validate this approach.

Correlations Between Imaging and Clinical, Functional and Biological Features in Knee Osteoarthritis

Background: For knee osteoarthritis (OA) pathogeny, cartilage damage is important, and ultrasonography (US) is helpful in assessing specific joint issues. Objectives: We intend to find correlations between functionality, pain level, serum glucose, cholesterol, triglycer-ides, uric acid, systemic inflammation and US findings for patients with knee OA. Meth-ods: For 50 consecutive subjects with symptomatic bilateral knee OA staged according to the scale Kellgren-Laurence(K-L) noted anamnestic data, Body Mass Index (BMI), func-tionality evaluated by Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and pain’ intensity through Visual Analogue Scale (VAS). Using the US, the cartilage, meniscal and tendon changes, osteophytes, and fluid collections were assessed for 100 knee joints. SPSS 29.0.2.0 was used for statistical analysis. Results: In our group, with an average age of 60.54 years, there was observed a weak direct correlation between WOMAC and K-L grading (r=0.34) and a negative correlation between BMI and the carti-lage size on the external femoral condyle (r=-0.28). Its thickness on this site was directly correlated with lateral osteophyte severity. Smokers' injuries on the intercondylar groove were increased. Conclusion: Lateral femoral condyle cartilage thickness is inversely asso-ciated with BMI, and K-L grading directly correlates with dysfunctionality. The smokers had higher intercondylar cartilage injuries. Keywords: Knee, osteoarthritis, pain, cartilage, ultrasonography.

Diagnostic value of ultrasonography in knee osteoarthritis: A systematic review.

Knee osteoarthritis (KOA) is the most expected diagnosis for an arthropathy that causes discomfort and disability in older adults. Radiography is frequently used to assess patients with KOA and there have been few prior research evaluating the diagnostic efficacy of ultrasonography (US). The current study sought to assess the diagnostic efficacy of the US in identifying various characteristics of KOA in the scientific literature. This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. A systematic search in PubMed, Web of Science, Scopus, and Embase databases was completed in March 2023. This study focused on the diagnostic value of US in KOA, including sensitivity, specificity, positive predictive value, and negative predictive value. The quality assessment was conducted using the Joanna Briggs Institute critical appraisal tools. Out of 552 records of database searches, finally, two studies met this systematic review's eligibility criteria and were included in the study. Both of the included studies were cross sectional studies. US demonstrated remarkable sensitivity with adequate specificity for the detection of radiographic knee OA; however, it was found not to be an appropriate method for the detection of early KOA. This study as the first systematic review aims to evaluate the diagnostic performance of US in detecting KOA. These findings shed light on the importance of investigating the different US features in the evaluation of KOA to reach appropriate sensitivity and specificity in the diagnosis.

Effect of umbilical cord blood-mononuclear cells on knee osteoarthritis in rabbits

BackgroundTo investigate the effect and underlying mechanism of umbilical cord blood-mononuclear cells (UCB-MNCs) in treating knee osteoarthritis (KOA) in rabbits.MethodsA rabbit KOA model was prepared by anterior cruciate ligament transection (ACLT). Fifty New Zealand white rabbits were randomly divided into the control group, model group, sodium hyaluronate (SH) group, platelet-rich plasma (PRP) group and UCB-MNC group. Knee injections were performed once a week for five consecutive weeks. The gross view of the knee joint, morphology of knee cartilage and structural changes in the knee joint were observed on CT scans, and graded by the Lequesne MG behavioral score and the Mankin score. TNF-α and IL-1β levels in the synovial fluid of the knee were measured by the enzyme-linked immunosorbent assay (ELISA). Expression levels of MMP-13 and COL-II in the knee cartilage were detected by Western blotting and qRT-PCR.ResultsThe Lequesne MG behavioral score and the Mankin score were significantly higher in the model group than those in the control group (P < 0.05). Rabbits in the SH, PRP and UCB-MNC groups had sequentially lower scores than those in the model group. Imaging features of KOA were more pronounced in the model group than in the remaining groups. CB-MNC significantly relieved KOA, compared to SH and PRP. Significantly higher levels of TNF-α and IL-1β in the synovial fluid of the knee, and up-regulated MMP-13 and down-regulated COL-II in the knee cartilage were detected in the model group than in the control group. These changes were significantly reversed by the treatment with SH, PRP and UCB-MNCs, especially UCB-MNCs.ConclusionInjections of UCB-MNCs into knees protect the articular cartilage and hinder the progression of KOA in rabbits by improving the local microenvironment at knee joints.

Matrix stiffening promotes chondrocyte senescence and the osteoarthritis development through downregulating HDAC3

Extracellular matrix (ECM) stiffening is a typical characteristic of cartilage aging, which is a quintessential feature of knee osteoarthritis (KOA). However, little is known about how ECM stiffening affects chondrocytes and other molecules downstream. This study mimicked the physiological and pathological stiffness of human cartilage using polydimethylsiloxane (PDMS) substrates. It demonstrated that epigenetic Parkin regulation by histone deacetylase 3 (HDAC3) represents a new mechanosensitive mechanism by which the stiffness matrix affected chondrocyte physiology. We found that ECM stiffening accelerated cultured chondrocyte senescence in vitro, while the stiffness ECM downregulated HDAC3, prompting Parkin acetylation to activate excessive mitophagy and accelerating chondrocyte senescence and osteoarthritis (OA) in mice. Contrarily, intra-articular injection with an HDAC3-expressing adeno-associated virus restored the young phenotype of the aged chondrocytes stimulated by ECM stiffening and alleviated OA in mice. The findings indicated that changes in the mechanical ECM properties initiated pathogenic mechanotransduction signals, promoted the Parkin acetylation and hyperactivated mitophagy, and damaged chondrocyte health. These results may provide new insights into chondrocyte regulation by the mechanical properties of ECM, suggesting that the modification of the physical ECM properties may be a potential OA treatment strategy.

Dual-energy X-ray absorptiometry derived knee shape may provide a useful imaging biomarker for predicting total knee replacement: Findings from a study of 37,843 people in UK Biobank

ObjectiveWe aimed to create an imaging biomarker for knee shape using knee dual-energy x-ray absorptiometry (DXA) scans and investigate its potential association with subsequent total knee replacement (TKR), independently of radiographic features of knee osteoarthritis and established risk factors. MethodsUsing a 129-point statistical shape model, knee shape (expressed as a B-score) and minimum joint space width (mJSW) of the medial joint compartment (binarized as above or below the first quartile) were derived. Osteophytes were manually graded in a subset of images and an overall score was assigned. Cox proportional hazards models were used to examine the associations of B-score, mJSW and osteophyte score with TKR risk, adjusting for age, sex, height and weight. ResultsThe analysis included 37,843 individuals (mean age 63.7 years). In adjusted models, B-score was associated with TKR: each unit increase in B-score, reflecting one standard deviation from the mean healthy shape, corresponded to a hazard ratio (HR) of 2.25 (2.08, 2.43), while a lower mJSW had a HR of 2.28 (1.88, 2.77). Among the 6719 images scored for osteophytes, mJSW was replaced by osteophyte score in the most strongly predictive model for TKR. In ROC analyses, a model combining B-score, osteophyte score, and demographics outperformed a model including demographics alone (AUC ​= ​0.87 vs 0.73). ConclusionsUsing statistical shape modelling, we derived a DXA-based imaging biomarker for knee shape that was associated with kOA progression. When combined with osteophytes and demographic data, this biomarker may help identify individuals at high risk of TKR, facilitating targeted interventions.

Quality of Life Assessment in Patients with Knee Osteoarthritis

IntroductionOsteoarthritis is one of the most common diseases and a leading cause of functional limitation and dependence, significantly impacting the quality of life (QOL).ObjectivesThe aim of this study was to evaluate the impact of knee osteoarthritis on QOL and identify associated factors.Methods This prospective cross-sectional descriptive study was conducted in the Physical Medicine and Functional Rehabilitation Department over a 4-month period, involving patients with symptomatic bilateral knee osteoarthritis (according to the American College of Rheumatology (ACR) criteria). Sociodemographic data, comorbidities, and characteristics of knee osteoarthritis were collected. The assessment of QOL and the functional impact of knee osteoarthritis were based on the KOOS (Knee Injury and Osteoarthritis Outcome Score) self-questionnaire, Lequesne Index, and modified WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) Score. The KOOS questionnaire included 5 subscales: pain (KOOS-Pain), symptoms other than pain (KOOS-Symptoms), activities of daily living (KOOS-ADL), sports and recreational function (KOOS-Sport), and QOL (KOOS-QOL).Results We included 30 patients with an average age of 59.27±6.3; the male-to-female ratio was 0.15. Sixty percent of patients lived in urban areas, with varying levels of education: primary (n=10), secondary (n=4), and university (n=4), while the majority were illiterate (40%). Most of our patients were employed, with 64.28% engaging in significant physical activity, resulting in an average of 6±2 days of work absenteeism every 3 months due to knee pain. The mean duration of knee osteoarthritis was 7.97 years±3.14. The average pain visual analog scale (VAS) score was 5.2±0.4. Knee osteoarthritis was classified as stage 2 in 40% and stage 3 in 60% of cases. Regarding functional impact, the mean WOMAC global index was 16.6±4.68, and the mean Lequesne Index was 11.05±3.45; moderate disability was observed in 16.7%, significant disability in 50%, and severe disability in 16.7% of patients. Furthermore, the KOOS questionnaire revealed decreased KOOS-Sport and KOOS-QOL scores, with mean values of 35±10.2 and 37±8.9, respectively. Our study identified factors associated with a poor quality of life: age &gt; 65 years (p&lt;0.05), disease duration (p=0.02), and VAS pain &gt; 5 (p=0.02).ConclusionsImproving the quality of life is an essential therapeutic goal in managing knee osteoarthritis. Our study demonstrates that advanced age, longer disease duration, and high pain intensity can negatively impact quality of life.Disclosure of InterestNone Declared

Assessment of a novel deep learning-based software developed for automatic feature extraction and grading of radiographic knee osteoarthritis

BackgroundThe Kellgren-Lawrence (KL) grading system is the most widely used method to classify the severity of osteoarthritis (OA) of the knee. However, due to ambiguity of terminology, the KL system showed inferior inter- and intra-observer reliability. For a more reliable evaluation, we recently developed novel deep learning (DL) software known as MediAI-OA to extract each radiographic feature of knee OA and to grade OA severity based on the KL system.MethodsThis research used data from the Osteoarthritis Initiative for training and validation of MediAI-OA. 44,193 radiographs and 810 radiographs were set as the training data and used as validation data, respectively. This AI model was developed to automatically quantify the degree of joint space narrowing (JSN) of medial and lateral tibiofemoral joint, to automatically detect osteophytes in four regions (medial distal femur, lateral distal femur, medial proximal tibia and lateral proximal tibia) of the knee joint, to classify the KL grade, and present the results of these three OA features together. The model was tested by using 400 test datasets, and the results were compared to the ground truth. The accuracy of the JSN quantification and osteophyte detection was evaluated. The KL grade classification performance was evaluated by precision, recall, F1 score, accuracy, and Cohen's kappa coefficient. In addition, we defined KL grade 2 or higher as clinically significant OA, and accuracy of OA diagnosis were obtained.ResultsThe mean squared error of JSN rate quantification was 0.067 and average osteophyte detection accuracy of the MediAI-OA was 0.84. The accuracy of KL grading was 0.83, and the kappa coefficient between the AI model and ground truth was 0.768, which demonstrated substantial consistency. The OA diagnosis accuracy of this software was 0.92.ConclusionsThe novel DL software known as MediAI-OA demonstrated satisfactory performance comparable to that of experienced orthopedic surgeons and radiologists for analyzing features of knee OA, KL grading and OA diagnosis. Therefore, reliable KL grading can be performed and the burden of the radiologist can be reduced by using MediAI-OA.

Prevalence and Characteristics of Knee Osteoarthritis Among the General Public in Saudi Arabia.

Background Knee osteoarthritis (OA) is a chronic and progressive knee joint condition that is influenced by multiple factors. This research aims to examine the prevalence and characteristics of knee OA among the general public in Saudi Arabia. Methodology This cross-sectional online survey was conducted in September 2023 in Saudi Arabia. This research used a previously developed questionnaire to validate the diagnosis of OA, which was performed in accordance with the diagnostic criteria established by the American College of Rheumatology (ACR). The Western Ontario and McMaster Universities Arthritis Index questionnaire (WOMAC) was used to examine the severity and characteristics of knee OA patients. A binary logistic regression analysis was conducted to determine the variables that influence the severity of knee OA and the likelihood of developing OA. Results A total of 1,019 individuals participated in this study. Around one-third of the participants (34.5%) fulfilled the ACR criteria for knee OA diagnosis. Overall, the mean WOMAC score was 34.1 (18.8) out of 96, which represents 35.5% of the maximum obtainable score and demonstrates a low degree of knee OA severity. The mean pain sub-scale score was 7.4 (3.8) out of 20, which represents 37.0% of the maximum obtainable score and demonstrates a low level of pain intensity. The mean stiffness sub-scale score was 2.7 (1.8) out of 8, which represents 33.8% of the maximum obtainable score and demonstrates a low degree of stiffness in joints. The mean physical function sub-scale score was 24.0 (14.0) out of 68, which represents 35.3% of the maximum obtainable score and demonstrates a low level of physical function difficulty. Females, older participants (above 40 years), those with high body mass index (28.8 kg/cm2 and higher), non-smokers, those with comorbidities, those who did not practice daily physical activity, those who had a family history of knee OA, and those who suffered from flat feet, rheumatoid arthritis, gout, lupus, or back or hip pain were more likely to develop knee OA and have severe OA (p < 0.05). Conclusions Thefindings of this study demonstrated a significant prevalence rate of kneeOA and highlighted a discrepancy between the rates obtained by diagnostic criteria and those determined through clinical diagnosis. Several significant factors that contribute to the development of OAencompass lifestyle choices such as food and exercise, familial predisposition, genetic influences, and the presence of comorbidities. To effectively tackle this intricate matter, it is imperative to adopt a patient-centered strategy and prioritize early intervention.

Factors associated with pain pressure threshold in both local and remote sites in knee osteoarthritis.

Knee osteoarthritis (KOA) is a prevalent condition, and its most frequent symptom is pain that often leads to disability. Pain sensitization is a core feature of KOA, and it can be measured through quantitative sensory testing protocols such as pain pressure threshold (PPT). However, there is a lack of understanding about the factors that may influence changes in PPTs in the KOA population. To explore the clinical and functional factors associated with PPTs in a sample of people with chronic KOA pain and to compare models of local (knees) and remote (thenar regions) sites. Cross-sectional analysis of a prospective cohort. Primary care in public institution. 113 adults with KOA. N/A. Multivariable regression analyses evaluating demographic, clinical, and functional variables that could be associated with local and remote PPTs (main outcomes) were performed. Both thenar region (adjusted-R2 : 0.29) and knee (adjusted-R2 : 0.45) models had the same significant negative association with being a female, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain levels (thenar: β: -0.15, p = .002; knee: β: -0.2, p < .001), and the 10-Meter Walking Test (thenar: β: -0.05, p = .038; knee: β: -0.08, p = .004). A small significant positive association with depressive symptoms was identified in both models, which acted as a confounder for WOMAC pain and was likely affected by unmeasured confounders. PPTs in KOA pain are associated with functional outcomes such as the 10-Meter Walking Test and activity-related pain intensity; thus more disability is associated with smaller pain thresholds. Similarity between models may suggest central sensitization.

Stratifying knee osteoarthritis features through multitask deep hybrid learning: Data from the osteoarthritis initiative

Background and objectiveKnee osteoarthritis (OA) is a debilitating musculoskeletal disorder that causes functional disability. Automatic knee OA diagnosis has great potential of enabling timely and early intervention, that can potentially reverse the degenerative process of knee OA. Yet, it is a tedious task, concerning the heterogeneity of the disorder. Most of the proposed techniques demonstrated single OA diagnostic task widely based on Kellgren Lawrence (KL) standard, a composite score of only a few imaging features (i.e. osteophytes, joint space narrowing and subchondral bone changes). However, only one key disease pattern was tackled. The KL standard fails to represent disease pattern of individual OA features, particularly osteophytes, joint-space narrowing, and pain intensity that play a fundamental role in OA manifestation. In this study, we aim to develop a multitask model using convolutional neural network (CNN) feature extractors and machine learning classifiers to detect nine important OA features: KL grade, knee osteophytes (both knee, medial fibular: OSFM, medial tibial: OSTM, lateral fibular: OSFL, and lateral tibial: OSTL), joint-space narrowing (medial: JSM, and lateral: JSL), and patient-reported pain intensity from plain radiography. MethodsWe proposed a new feature extraction method by replacing fully-connected layer with global average pooling (GAP) layer. A comparative analysis was conducted to compare the efficacy of 16 different convolutional neural network (CNN) feature extractors and three machine learning classifiers. ResultsExperimental results revealed the potential of CNN feature extractors in conducting multitask diagnosis. Optimal model consisted of VGG16-GAP feature extractor and KNN classifier. This model not only outperformed the other tested models, it also outperformed the state-of-art methods with higher balanced accuracy, higher Cohen's kappa, higher F1, and lower mean squared error (MSE) in seven OA features prediction. ConclusionsThe proposed model demonstrates pain prediction on plain radiographs, as well as eight OA-related bony features. Future work should focus on exploring additional potential radiological manifestations of OA and their relation to therapeutic interventions.

Features of Knee and Multijoint Osteoarthritis by Sex and Race and Ethnicity: A Preliminary Analysis in the Johnston County Health Study.

To evaluate knee osteoarthritis (KOA) and multijoint osteoarthritis (MJOA), and to compare features by sex and race and ethnicity in a population-based cohort. Participants (n = 544) enrolled in the Johnston County Health Study (JoCoHS) as of January 2023 were categorized by radiographic and symptomatic KOA and MJOA phenotypes, and frequencies were compared by sex and race and ethnicity. Symptoms were assessed according to the Knee Injury and Osteoarthritis Outcome Score (KOOS) and pain, aching, and stiffness (PAS) scores at various joints. Models produced estimates (odds ratio [OR] or mean ratios [MR] and 95% CI) adjusted for age, BMI (kg/m2), and education. Men had twice the odds of having MJOA-6 (≥ 3 lower extremity joints affected); there were no significant differences in MJOA phenotypes by race and ethnicity. Women had 50% higher odds of having KOA or having various features of KOA. Women reported significantly worse KOOS Symptoms scores (MR 1.25). Black participants had higher odds of more severe KOA (OR 1.47), subchondral sclerosis (OR 2.06), and medial tibial osteophytes (OR 1.50). Black participants reported worse KOOS Symptoms than White participants (MR 1.18). Although not statistically significant, Hispanic participants (vs non-Hispanic participants) appeared to have lower odds of radiographic changes but reported worse symptoms. Preliminary findings in the diverse JoCoHS cohort suggest more lower extremity- predominant MJOA in men compared to women. Women and Black participants had more KOA features and more severe symptoms. Hispanic participants appear to have higher pain and symptoms scores despite having fewer structural changes. Studies in diverse populations are needed to understand the burden of OA.

Comparative Effect of Faradic and Russian Currents on the Quadriceps Muscle in Patients with Knee Osteoarthritis

Abstract: Osteoarthritis is amongst the most common musculoskeletal condition which affects overall function and quality of life in the Indian population. Clinical features of knee osteoarthritis include pain that affects the functional mobility of joints and thus interferes with walking and activities of daily living. Quadriceps function declines with age, and is further impaired in patients with knee and may contribute to the risk of falls. The aim of the present study was to compare the effect of Faradic and Russian Currents on the quadriceps muscle in Patients with knee osteoarthritis. Objectives: To evaluate the effect of Faradic Currants on the quadriceps muscle for the management ofknee osteoarthritis. To evaluate the effects of Russian Currants on the quadriceps muscle for t h e management of knee osteoarthritis. To Comparative effects between Faradic and Russian Currants on the quadriceps muscle formanagement of knee osteoarthritis. Methodology: Permission from the head of the department of Sanskriti University Mathura, and approval from the ethical committee. Patients pre-diagnosed with grade II OA were selected for this study. Consent was taken from the patients after confirming the diagnosis of Grade II OA. The subjects were divided into two groups (15 in each group): one group consist of a Faradic current + quadriceps isometric exercise (5 days a week for 4 weeks) and the second group consisted of a Russian current + quadriceps isometric exercise (5 days in a week for 4 weeks). Result: The statistics a r e done based on the objectives and hypotheses and it has been organized by following three sections: Section I: Frequency and percentage distributions of socio-demographic variables.Section II: Effectiveness of pre and post-test values. Section III: Comparison of Faradic Currants and Russian Currants Values. Conclusion: This study concludes that faradic current and Russian current show significant effect in quadriceps muscle in patients with knee osteoarthritis and there is no significant difference between faradic and Russian current on quadriceps muscle Patients with knee osteoarthritis.But the only significant difference in WOMAC scores after intervention (The WOMAC score ismore decreased in Russian as compared to faradic current)

Honey improves radiographic features of monosodium iodoacetate-induced stifle (knee) joint osteoarthritis in a rat model

Osteoarthritis (OA) is the most common form of joint disease with over half of all people older than 65 years demonstrating radiographic changes of osteoarthritis in the knees. Honey is known to contain bioactive compounds that exert chondroprotective effects by counteracting the homeostatic dysregulation of the joint. However, its effect on the radiographic features of osteoarthritis has not been proven. This study was carried out to evaluate the effect of honey on radiographic features of monosodium iodoacetate (MIA)- induced knee osteoarthritis in female Wistar rats. Thirty female Wistar rats were randomly divided into five groups of six animals each. Animals in group one were healthy (control) rats, while animals in groups two to five were subjected to experimental osteoarthritis of the right knee joint induced by a single intra-articular injection of 1mg of MIA. The animals in groups two, three, four, and five were treated with normal saline (1ml/kg b. w.), arthocare (glucosamine/chondroitin sulfate 6.67/8.33mg/kg b. w.), low dose honey (250mg/kg b. w.) and high dose honey (1,000mg/kg b. w.) respectively. All treatments were administered orally once daily using an oral cannula for twenty-one days. All animals were subjected to radiographic assessment of the right knee joint before and after induction of OA, and after treatment. High and low-dose honey reversed the loss of joint space; sclerosis of the tibial plateau, medial, and lateral femoral condyles, when compared to the arthocare-treated and untreated groups. In conclusion, honey improved radiographic features of knee osteoarthritis in a rat model induced by monosodium iodoacetate.

Histological features of knee osteoarthritis treated with triamcinolone acetonide and hyaluronic acid.

Osteoarthritis (OA) is one of the most common degenerative joint diseases leading to disability in the end stage. Although intra-articular triamcinolone acetonide (TA) is one of the OA treatments that have been widely used, the side effects of such corticosteroids are still controversial. Intra-articular hyaluronic acid (HA) injection is another therapeutic option for patients with OA who do not want to use corticosteroids because of their side effects. However, the difference between the histological features associated with TA and HA in the treatment of OA remains unclear. Thus, the present study aimed to compare the histological effects of TA and HA on the cartilage of patients with knee OA. In the current study, 31 patients diagnosed with grade 3-4 knee OA on the Kellgren-Lawrence radiographic grading scale were separated into three groups: TA (n=12); HA (n=7) and untreated group (n=12). Histological examination of the whole articular cartilages of the patients was performed with hematoxylin and eosin and Alcian staining, as well as using a TUNEL assay. Clinical data such as cartilage thickness, structural and component deterioration, proteoglycan levels, apoptosis and empty lacunae were compared between the three groups. The results showed a high level of deterioration in both TA and HA groups but not in the untreated group, although the thickness of cartilage in the HA group was lower compared with that in the TA and untreated groups. The proteoglycan levels in the TA group were lower compared with those in the HA group. Moreover, the number of empty lacunae in the HA group was higher compared with that in the TA group, while no difference in apoptosis was found between TA and HA groups. A significant difference was not found in the histological staining between TA and HA groups. On the other hand, a significant difference was found in cartilage deterioration between the medial and lateral sides in these groups. TA and HA groups showed comparable histological results. TA injection is cheaper and easier but has more adverse effects for patients with knee OA than HA injection. Therefore, orthopaedists should select TA or HA based on the economic and specific needs of patients.

Chrysin ameliorates synovitis and fibrosis of osteoarthritic fibroblast-like synoviocytes in rats through PERK/TXNIP/NLRP3 signaling.

Objective: Synovitis and fibrosis are common pathological features of knee osteoarthritis (KOA). The interaction of synovitis and fibrosis can promote KOA progression. Chrysin (CHR), a natural flavonoid, may treat inflammation and prevent fibrosis. However, the effect and mechanism of CHR in KOA synovitis and fibrosis remains unclear. Methods: The KOA model was established in male SD rats by anterior cruciate ligament transection (ACLT), and histological analysis was used to evaluate synovitis and fibrosis. IL-6, IL-1β and TNF-α mRNA expression in synovial tissue was measured by qRT‒PCR. Immunohistochemistry (IHC) was performed to detect GRP78, ATF-6 and TXNIP expression in vivo. Synovial fibroblasts (SFs) were treated with TGF-β1 to stimulate the inflammatory response and fibrosis. CCK-8 assays were used to detect the viability of CHR-treated SFs. The IL-1β level was detected by immunofluorescence analysis. Coimmunoprecipitation (Co-IP) and double immunofluorescence colocalization were used to detect the physiological interaction between TXNIP and NLRP3. The expression of fibrosis-related mediators and PERK/TXNIP/NLRP3 signaling molecules was detected by western blotting and qRT-PCR. Results: Four weeks after CHR treatment, pathological sections and associated scores showed that CHR improved synovitis and fibrosis in the ACLT model. In vitro, CHR attenuated the TGF-β1-induced inflammatory response and fibrosis in SFs. Moreover, CHR suppressed the expression of synovial fibrosis markers and PERK/TXNIP/NLRP3 signaling molecules in the synovial tissue of rats with ACLT and cultured SFs. More importantly, we found that CHR inhibited TXNIP-NLRP3 interactions in TGF-β-induced SFs. Conclusion: Our findings indicate that CHR can ameliorate synovitis and fibrosis in KOA. The underlying mechanism may be related to the PERK/TXNIP/NLRP3 signaling pathway.

Can serum MMP-3 diagnose early knee osteoarthritis?

AimsThis study aims to assess the ability of serum MMP-3 levels to differentiate between normal knee with primary knee osteoarthritis (KOA) and its ability to differentiate between various severity grades. Material & methodsThe study included 80 cases of primary knee osteoarthritis (KOA) and 80 young individuals with no features of KOA. ResultsThe subjects in Case group were younger (52.80 ± 10.31 years) than in Control group (28.55 ± 5.98 years) (p = 0.001). The BMI of Case group (27.5 ± 4.81 kg/m2) was significantly higher than in Control group (25.40 ± 5.71 kg/m2) (p = 0.012). Mean sMMP-3 level in Cases (59.85 ± 39.92 ng/ml) was significantly higher than in Controls (14.52 ± 6.09 ng/ml) (p = 0.0001). There was no gender difference in biomarker values in Cases (p = 0.1) and in Controls (p = 0.88). The level of sMMP-3 rises with increasing age in cases only (p = 0.0001). MMP-3 values were significantly elevated in cases in the sub-categories of BMI within case group and control group (>0.05) but higher in cases in normal, overweight and obese subcategories (p < 0.05). Serum MMP-3 level differs significantly between K-L grade 0-I (p = 0.004), K-L grade I-II (p = 0.000), K-L grade II-III (p = 0.007) and also between K-L grade III-IV (p = 0.02). Biomarker showed moderate positive correlation with KL grade (r = 0.68, p = 0.000) and age (r = 0.38, p = 0.000) and weak positive correlation with WOMAC score (r = 0.289, p = 0.009). The receiver operative curve (ROC) analysis suggested a cut off value of sMMP-3 as 20.03 ng/ml between Control group and Case group, as 12.25 ng/ml between K-L grade 0-I; as 18.37 ng/ml between K-L grade I-II; as 55.60 ng/ml between K-L grade II-III; as 102.0 ng/ml between K-L grade III-IV. ConclusionssMMP-3 estimation as a tool has a good discriminatory power to differentiate between healthy and a diseased knee (KOA) and between severity grades. It can be used as a test to identify individuals with KL grade I and II of KOA.

Deep learning applications in osteoarthritis imaging.

Deep learning (DL) is one of the most exciting new areas in medical imaging. This article will provide a review of current applications of DL in osteoarthritis (OA) imaging, including methods used for cartilage lesion detection, OA diagnosis, cartilage segmentation, and OA risk assessment. DL techniques have been shown to have similar diagnostic performance as human readers for detecting and grading cartilage lesions within the knee on MRI. A variety of DL methods have been developed for detecting and grading the severity of knee OA and various features of knee OA on X-rays using standardized classification systems with diagnostic performance similar to human readers. Multiple DL approaches have been described for fully automated segmentation of cartilage and other knee tissues and have achieved higher segmentation accuracy than currently used methods with substantial reductions in segmentation times. Various DL models analyzing baseline X-rays and MRI have been developed for OA risk assessment. These models have shown high diagnostic performance for predicting a wide variety of OA outcomes, including the incidence and progression of radiographic knee OA, the presence and progression of knee pain, and future total knee replacement. The preliminary results of DL applications in OA imaging have been encouraging. However, many DL techniques require further technical refinement to maximize diagnostic performance. Furthermore, the generalizability of DL approaches needs to be further investigated in prospective studies using large image datasets acquired at different institutions with different imaging hardware before they can be implemented in clinical practice and research studies.

Changes and Associations Between Gait Biomechanics and Knee Inflammation After Aspiration and Glucocorticoid Injection for Knee Osteoarthritis.

Although knee inflammation is thought to adversely affect joint function in patients with knee osteoarthritis (OA), the effects of reducing knee inflammation on gait biomechanics and strength are unknown. Our objectives were to compare ultrasound (US) measures of knee inflammation, gait biomechanics, knee extension and flexion strength, and pain before and after knee aspiration and glucocorticoid injection, and to explore associations among changes. Forty-nine patients (69 knees) with symptomatic knee OA and synovitis were tested before and 3-4 weeks after US-guided knee aspiration and glucocorticoid injection. At each visit, participants completed US assessments for inflammatory features of knee OA, 3D gait analysis, isokinetic knee extension and flexion strength tests, and Knee Osteoarthritis Outcome Score (KOOS) pain subscales. Linear and polynomial mixed-effects regression models were used to investigate changes and their associations. Changes were observed for the synovitis score (unstandardized β [post-injection minus pre-injection] -0.55/9 [95% confidence interval (95% CI) -0.97, -0.12]), effusion depth (-1.05 mm [95% CI -1.07, -0.39]), KOOS pain (unstandardized β 5.91/100 [95% CI 1.86, 9.97]), peak external knee flexion and extension moments (KFM; 3.33 Nm [95% CI 0.45, 6.22]), KEM (-2.99 Nm [95% CI -5.93, -0.05]), and knee extension strength (4.70 Nm [95% CI 0.39, 9.00]) and flexion strength (3.91 Nm [95% CI 1.50, 6.81]). The external KFM increased during 13-38% and 76-89% of stance post-injection. When controlled for time, greater synovitis was associated with lower knee extension strength, while lower pain was associated with increased knee extension and flexion strength. In patients with knee OA and synovitis, reduced inflammation and pain after aspiration and glucocorticoid injection are associated with changes in knee gait biomechanics and strength.

Association of Traumatic Knee Injury With Radiographic Evidence of Knee Osteoarthritis in Military Officers.

The association between knee injury and knee osteoarthritis (OA) is understudied relative to its importance, particularly in younger populations. This study was undertaken to examine the association of knee injury with radiographic features of knee OA in military officers, who have a physically demanding profession and high rates of knee injury. Participants were recruited in 2015-2017 from an existing program that enrolled 6,452 military officers during 2004-2009. Officers with a history of knee ligament or meniscal injuries (n=117 via medical record review) were compared to officers with no history of knee injury (n=143). Bilateral posteroanterior knee radiographs were obtained using a standardized fixed-flexion positioning frame. All images were read for Kellgren/Lawrence (K/L) grade, osteophyte (OST), and joint space narrowing (JSN) scores. Data were analyzed using linear-risk regression models with generalized estimating equations. Injured and noninjured participants were similar (mean age 28 years, mean body mass index 25 kg/m2 , ~40% female). The mean time from first knee injury to imaging among injured participants was 9.2 years. Compared with noninjured knees, greater prevalence of radiographic OA (K/L grade ≥ 2), OST (grade ≥ 1), and JSN (grade ≥ 1) was observed among injured knees, with prevalence differences of +16% (95% confidence interval [95% CI] 10%, 22%), +29% (95% CI 20%, 38%), and + 17% (95% CI 10%, 24%), respectively. Approximately 1 in 6 officers with prior knee injury progressed to radiographic OA by age 30 years. At the midpoint of a projected 20-year military career, officers with a history of traumatic knee injury have a markedly increased prevalence of knee radiographic OA compared to officers without injury.