Incident Symptomatic Knee Research Articles

Weight-Bearing Physical Activity, Lower-Limb Muscle Mass, and Risk of Knee Osteoarthritis.

It has been demonstrated that total physical activity is not associated with risk of osteoarthritis. However, the association of different types of physical activity with incident knee osteoarthritis remains unclear. To determine whether weight-bearing recreational physical activities are associated with increased risk of incident knee osteoarthritis. This prospective cohort study used data from the Rotterdam Study (1996 to 2009), including participants with knee x-ray measurements at baseline and follow-up examinations. Participants with knee osteoarthritis at baseline were excluded. Residents aged 45 years and older of the Ommoord district in the city of Rotterdam in The Netherlands were invited to join the Rotterdam Study (78% response rate). Analysis was conducted in June 2023. Total, weight-bearing, and non-weight-bearing recreational physical activities collected by questionnaires at baseline. Incident radiographic knee osteoarthritis measured by knee x-ray was the primary outcome, and incident symptomatic knee osteoarthritis defined by x-ray and knee pain questionnaire was the secondary outcome. The association of different types of recreational physical activity with radiographic knee osteoarthritis was examined using logistic regression within generalized estimating equation framework after adjusting for potential confounders. A prespecified stratification analysis was planned on the basis of lower-limb muscle mass index (LMI) tertiles, measured by dual-energy x-ray absorptiometry. A total of 5003 individuals (2804 women [56.0%]; mean [SD] age, 64.5 [7.9] years) were included. The knee osteoarthritis incident rate was 8.4% (793 of 9483 knees) for a mean (SD) follow-up time of 6.33 (2.46) years. Higher weight-bearing activity was associated with increased odds of incident knee osteoarthritis (odds ratio [OR], 1.22; 95% CI, 1.10-1.35; P < .001), but non-weight-bearing activity was not (OR, 1.04; 95% CI, 0.95-1.15; P = .37). In the analysis stratified by LMI tertiles, the association of weight-bearing activity with incident osteoarthritis was found only among 431 patients in the lowest LMI tertile (OR, 1.53; 95% CI, 1.15-2.04; P = .003), but not among patients in the middle or high LMI tertile. The findings of this study suggest that weight-bearing activity is associated with incident knee osteoarthritis in people with low levels of lower-limb muscle mass, which might be a promising avenue for tailored advice for physical activity.

Essential Fatty Acids and Osteoarthritis.

Inflammation worsens joint destruction in osteoarthritis (OA) and aggravates pain. Although n-3 fatty acids reduce inflammation, different n-3 fatty acids have different effects on inflammation and clinical outcomes, with eicosapentaenoic acid (EPA) having the strongest effect. We examined whether specific essential fatty acid levels affected the development of OA. We studied participants from the Multicenter Osteoarthritis Study (MOST) at risk of developing knee OA. As part of MOST, participants were asked repeatedly about knee pain, and knee radiographs and magnetic resonance images (MRIs) were obtained. Using baseline fasting samples, we analyzed serum fatty acids with standard assays. After excluding participants with baseline OA, we defined two sets of cases based on their status through 60 months' follow-up: those developing incident radiographic OA and those developing incident symptomatic OA (knee pain and radiographic OA). Controls did not develop these outcomes. Additionally, we examined worsening of MRI cartilage damage and synovitis and worsening knee pain and evaluated the number of hand joints affected by nodules. In regression models, we tested the association of each OA outcome with levels of specific n-3 and n-6 fatty acids, adjusting for age, sex, body mass index, education, physical activity, race, baseline pain, smoking, statin use, and depressive symptoms. We studied 363 cases with incident symptomatic knee OA and 295 with incident radiographic knee OA. The mean age was 62 years (59% women). We found no associations of specific n-3 fatty acid levels, including EPA, or of n-6 fatty acid levels with incident OA (eg, for incident symptomatic knee OA, the odds ratio per SD increase in EPA was 1.0 [95% confidence interval 0.87-1.17]). Results for other OA outcomes also failed to suggest a protective effect of specific n-3 fatty acids with OA outcomes. We found no association of serum levels of EPA or of other specific n-3 fatty acids or n-6 fatty acids with risk of incident knee OA or other OA outcomes.

Melatonin is a potential novel analgesic agent for osteoarthritis: Evidence from cohort studies in humans and preclinical research in rats.

Melatonin exhibits potential for pain relief and long-term safety profile. We examined the analgesic effects of oral melatonin on osteoarthritis (OA) and investigated the underlying mechanism. Using data from a UK primary care database, we conducted a cohort study in individuals with OA to compare the number of oral analgesic prescriptions and the risk of knee/hip replacement between melatonin initiators and hypnotic benzodiazepines (i.e., active comparator) initiators using quantile regression models and Cox-proportional hazard models, respectively. To elucidate causation, we examined the effects of melatonin on pain behaviors and explored several metabolites that may serve as potential regulatory agents of melatonin in the monoiodoacetate rat model of OA. Using data from another community-based cohort study,that is, the Xiangya OA Study, we verified the association between the key serum metabolite and incident symptomatic knee OA. Compared with the hypnotic benzodiazepines cohort (n = 8135), the melatonin cohort (n = 813) had significantly fewer subsequent prescriptions of oral analgesics (50th percentile: 5 vs. 7, 75th percentile: 19 vs. 29, and 99th percentile: 140 vs. 162) and experienced a lower risk of knee/hip replacement (hazard ratio = 0.47, 95% Cl: 0.30-0.73) during the follow-up period. In rats, oral melatonin alleviated pain behaviors and increased serum levels of glycine. There was an inverse association between baseline serum glycine levels and the risk of incident symptomatic knee OA in humans (n = 760). In conclusion, our findings indicate that oral melatonin shows significant potential to be a novel treatment for OA pain. The potential role of glycine in its analgesic mechanism warrants further investigation.

Roles of low muscle strength and sarcopenic obesity on incident symptomatic knee osteoarthritis: A longitudinal cohort study.

Sarcopenia is prevalent in middle to old age. We aimed to investigate the association between muscle strength and the incident knee osteoarthritis (OA). 12,043 participants were collected from the China Health and Retirement Longitudinal Study. The effects of sarcopenic obesity (defined by obesity in combination with possible sarcopenia) on knee OA onset were calculated using Poisson regression models. Mediation analysis was fit to estimate mediating proportion of muscle strength on the association between obesity and incident knee OA. The study all enrolled 12,043 participants with 2,008 progressed to knee OA. Poisson analyses demonstrated causal association of general obesity (RR:1.23, 95% CI: 1.08 to 1.39) and abdominal obesity (RR:1.23, 95% CI: 1.11 to 1.35) with knee OA onset. For the risk of incident knee OA, participants with the highest level of normalized grip strength had a decreased risk of incident knee OA by 0.33 (RR:0.67, 95% CI: 0.60 to 0.75) times compared to the control group, and chair-rising time was associated with increased risk of incident knee OA by 0.65 (RR:1.65, 95% CI: 1.17 to 2.33) times. Sensitivity analysis identified similar results. Participants with sarcopenic obesity were about 2 times risk of incident knee OA than reference group. Normalized grip strength and chair-rising time mediated the association between obesity and incidence of knee OA. Sarcopenic obesity is correlated with an increased risk of knee OA. Muscle strength recovery may alleviate the risk of incident knee OA in middle to old age with obesity.

The KNee OsteoArthritis Prediction (KNOAP2020) challenge: An image analysis challenge to predict incident symptomatic radiographic knee osteoarthritis from MRI and X-ray images

The KNee OsteoArthritis Prediction (KNOAP2020) challenge was organized to objectively compare methods for the prediction of incident symptomatic radiographic knee osteoarthritis within 78 months on a test set with blinded ground truth. The challenge participants were free to use any available data sources to train their models. A test set of 423 knees from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study consisting of magnetic resonance imaging (MRI) and X-ray image data along with clinical risk factors at baseline was made available to all challenge participants. The ground truth outcomes, i.e., which knees developed incident symptomatic radiographic knee osteoarthritis (according to the combined ACR criteria) within 78 months, were not provided to the participants. To assess the performance of the submitted models, we used the area under the receiver operating characteristic curve (ROCAUC) and balanced accuracy (BACC). Seven teams submitted 23 entries in total. A majority of the algorithms were trained on data from the Osteoarthritis Initiative. The model with the highest ROCAUC (0.64 (95% confidence interval (CI): 0.57-0.70)) used deep learning to extract information from X-ray images combined with clinical variables. The model with the highest BACC (0.59 (95% CI: 0.52-0.65)) ensembled three different models that used automatically extracted X-ray and MRI features along with clinical variables. The KNOAP2020 challenge established a benchmark for predicting incident symptomatic radiographic knee osteoarthritis. Accurate prediction of incident symptomatic radiographic knee osteoarthritis is a complex and still unsolved problem requiring additional investigation.

ALKYLRESORCINOL, A BIOMARKER FOR WHOLE GRAIN INTAKE, IS NOT ASSOCIATED WITH OSTEOARTHRITIS: THE MULTICENTER OSTEOARTHRITIS (MOST) STUDY

Purpose: Whole grain wheat and rye cereal are major sources of dietary fiber. Wheat, in particular, is a major source of fiber in the US. Whole grain cereal intake has been inversely associated with chronic disease risk. Similar relationships have been reported for incident symptomatic osteoarthritis (OA) and knee pain persisting after adjustment for confounders. Total fiber intake assessed using food frequency questionnaires, has been reported to be inversely associated with symptomatic knee osteoarthritis (KOA) risk in both the Framingham Osteoarthritis and the Osteoarthritis Initiative (OAI) studies (Dai et al, ARD 2017).

Magnetic Resonance Imaging-Assessed Subchondral Cysts and Incident Knee Pain and Knee Osteoarthritis: Data From the Multicenter Osteoarthritis Study.

To examine whether knee subchondral cysts, measured on magnetic resonance imaging (MRI), are associated with incident knee osteoarthritis (OA) outcomes. We used longitudinal data from the Multicenter Osteoarthritis Study, a community-based cohort of subjects with risk factors for knee OA. Participants without a history of knee surgery and/or inflammatory arthritis (i.e., rheumatoid arthritis and gout) were followed up for 84 months for the following incident outcomes: 1) radiographic knee OA (Kellgren/Lawrence grade ≥2), 2) symptomatic radiographic knee OA (radiographic knee OA and frequent knee pain), and 3) frequent knee pain (with or without radiographic knee OA). In a subset of participants, subchondral cysts were scored on baseline MRIs of 1 knee. Multiple logistic regression, with adjustment for participant characteristics and other baseline knee MRI findings, was used to assess whether subchondral cysts were predictive of incident outcomes. Among the participants with knees eligible for analyses of outcomes over 84 months, incident radiographic knee OA occurred in 22.8% of knees with no baseline radiographic knee OA, symptomatic radiographic knee OA occurred in 17.0% of knees with no baseline symptomatic radiographic knee OA, and frequent knee pain (with or without radiographic knee OA) occurred in 28.8% of knees with no baseline radiographic knee OA and 43.7% of knees with baseline radiographic knee OA. With adjustment for age, sex, and body mass index, the presence of subchondral cysts was not associated with incident radiographic knee OA but was associated with increased odds of incident symptomatic radiographic knee OA (odds ratio 1.92 [95% confidence interval 1.16-3.19]) and increased odds of incident frequent knee pain in those who had radiographic knee OA at baseline (odds ratio 2.11 [95% confidence interval 0.87-5.12]). Stronger and significant associations were observed for outcomes based on consistent reports of frequent knee pain within ~1 month of the study visit. Subchondral cysts are likely to be a secondary phenomenon, rather than a primary trigger, of radiographic knee OA, and may predict symptoms in knees with existing disease.

An interpretable deep learning model to predict symptomatic knee osteoarthritis

Purpose: Purpose- Early prediction of knee osteoarthritis may help to initiate potential interventions or treatments sooner, which can result in preventing or delaying knee osteoarthritis development. In this study, we aim to develop a deep learning (DL) prediction model to predict the incident symptomatic radiographic knee osteoarthritis over the next 78 months using radiographs at baseline. Methods: 427 knee radiography images from the Osteoarthritis Initiative (OAI) dataset were used to train and validate our model, with a mean age of 55.7 (SD: 3.2, range: 50 - 62) years and a mean BMI of 31.7 (SD: 3.7, range: 26.1 - 47.1) kg/m2. All subjects had Kellgren-Lawrence (KL) grades of 0 or 1 without symptoms at baseline. Incident symptomatic knee osteoarthritis was defined as knee pain and a definite tibiofemoral osteophyte in the same knee developed at 78-month follow up. Attention scores and probability of symptomatic knee osteoarthritis from radiography images were first extracted using an interpretable hierarchical attention-based convolutional neural network (CNN) model. The proposed model leveraged a transfer learning approach based on VGG-16 architecture. A 5-fold stratified cross-validation was used to evaluate and tune the neural network with 20% of training data as validation set in each fold. Twelve clinical variables including: age, body mass index (BMI), gender, KL grade, varus malalignment, history of knee injury, mild symptoms, presence of Heberden nodes, joint line tenderness, crepitus, morning stiffness and postmenopausal status, along with the attention and probability scores from our trained CNN, were then fed into a logistic regression model to predict the 78-month probability of knee osteoarthritis incident for each individual. The developed model was evaluated using an independent test set of 108 baseline knee radiographs from the OAI dataset (age, BMI, KL distribution, no symptoms at baseline). Results: The developed multi-modal model using radiographs and 12 clinical variables demonstrated an area under the receiver operating characteristic curve (AUC) of 0.91 (Figure 1), which outperforms the results reported in the literature using deep learning based methods. Moreover, the proposed model is interpretable, which can detect the specific location of potential abnormalities within knee images using the learned attention scores (Figure 2). Conclusions: A novel deep learning-based predictive model that takes knee radiographs and clinical variables as inputs was developed. It can predict the risk of symptomatic knee osteoarthritis incident over the next 6.5 years with a high AUC value. The attention maps on knee images confirm that the model predictions at baseline match the knee progression pattern in the course of the disease.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Metabolic osteoarthritis – relation of diabetes and cardiovascular disease with knee osteoarthritis

There is an interest in identifying a metabolic OA phenotype. We therefore assessed the relation of diabetes and cardiovascular disease to prevalent and incident radiographic (ROA) and symptomatic knee osteoarthritis (SxOA). In two large cohort studies of individuals with or at risk for knee OA, the Multicenter Osteoarthritis Study (MOST) and Osteoarthritis Initiative (OAI), participants self-reported diabetes and cardiovascular disease (CVD) at baseline. We assessed the relation of baseline diabetes and CVD (exposures) to ROA and SxOA cross-sectionally and after 60 (MOST) or 48 (OAI) months of follow-up using logistic regression with GEE to account for 2 knees within an individual, adjusting for potential confounders. In MOST, 6,020 knees of 3,021 participants (60.1% female, mean±SD age 62.5±8.1, mean BMI 30.7±6.0, 83.3% Caucasian) were included in the analyses. In OAI, 8,645 knees of 4,339 participants (58.2% female, mean±SD age 61.1±9.2, mean BMI 28.6±4.8, 80.3% Caucasian) were included. We found no significant associations between prevalent diabetes or CVD and prevalent or incident ROA or SxOA. Effect estimates for prevalent ROA and SxOA ranged from 0.80 (95% CI 0.63-1.03) to 1.17 (0.91-1.51). Effect estimates for incident ROA ranged from 0.80 (0.58-1.11) to 0.88 (0.60-1.29) in MOST and from 0.75 (0.50-1.14) to 1.19 (0.81-1.74) in OAI, and for incident SxOA from 0.93 (0.65-1.31) to 1.22 (0.89-1.67) in MOST and from 0.82 (0.59-1.16) to 1.19 (0.85-1.66) in OAI). Diabetes and CVD were not associated with prevalent or incident knee OA.

Incidence and risk factors of symptomatic knee osteoarthritis among the Chinese population: analysis from a nationwide longitudinal study

BackgroundKnee osteoarthritis (OA) is a common disease condition associated with aging and a frequent cause of primary care consultations. Few longitudinal studies have been conducted to investigate the incidence of symptomatic knee osteoarthritis (OA) and to identify its risk factors among the Chinese population.MethodsThe China Health and Retirement Longitudinal Study (CHARLS) is a nationwide longitudinal survey of persons aged ≥45 years. Symptomatic knee OA was diagnosed when both self-reported knee pain and self-reported physician-diagnosis arthritis existed. Using the national survey data collected from the CHARLS, we estimated the incidence of symptomatic knee OA, taking into account the complex survey design and response rate. We applied weighted logistic regression analysis to identify its risk factors.ResultsIn the 4-year follow-up, the cumulative incidence of symptomatic knee OA among middle-aged and older Chinese adults was 8.5%; the incidence was higher among females (11.2%) than males (5.6%). Female (odds ratio (OR) 1.98 [95% confidence interval (CI) 1.65–2.37]), rural area (OR 1.32 [95% CI 1.08–1.60]), and West region (OR 2.33 [95% CI 1.89–2.87]) were associated with a higher risk of incident symptomatic knee OA. Physical activities (OR 0.47 [95% CI 0.29–0.76]) and high education level (OR 0.60 [95% CI 0.41–0.88]) was associated with a lower risk of incident symptomatic knee OA, while histories of heart disease (OR 1.40 [95% CI 1.07–1.82]), kidney disease (OR 1.80 [95% CI 1.35–2.39]), and digestive disease (OR 1.54 [95% CI 1.30–1.82]) were associated with a higher risk of incident symptomatic knee OA.ConclusionThe cumulative incidence of symptomatic knee OA over 4 years was relatively high, and varied by province and region. Lack of physical activities was confirmed to be risk factors of incident symptomatic knee OA. The presence of heart disease, kidney disease, and digestive disease may be associated with a higher risk of incident symptomatic knee OA, further research need to confirm these findings.

Inflammatory potential of diet and risk of knee osteoarthritis: data from the osteoarthritis initiative

Purpose: Diet plays a fundamental role in prevention of many chronic diseases by regulating inflammation and body weight. The evidence of diet in OA development is accumulating. We aimed to examine the relation of inflammatory potential of diet, a modifiable risk factor, to incident knee osteoarthritis (OA) and the role of BMI in the association of interest. Methods: We used data from the Osteoarthritis Initiative. Dietary inflammatory index®(DII®) was calculated based on theBlock Brief 2000 Food Frequency Questionnaire and categorized into sex-specific quartiles. DII® is a literature-derived population-based scoring algorithm to assess the inflammatory potential of diet as a whole and was evaluated for validity and shown to predict inflammatory markers. A higher score of DII® indicates a greater inflammatory potential of diet (i.e., pro-inflammatory effect of diet). Outcomes were incident radiographic knee OA (ROA) (i.e., a KL grade ≥2) and incident symptomatic knee OA (SxOA) (i.e., a combination of a frequent knee pain and ROA). We examined the association of DII® with the risk of knee ROA (or SxOA) by comparing a higher quartile (Q2, Q3 and Q4) with the lowest quartile (Q1: reference category) using generalized estimating equations to account for the correlation between two knees for each participant. In the base model (model 1), we adjusted for age, sex (men vs. women), race (white vs. non-white) and total energy intake (kcal/day). In model 2, we further adjusted for educational attainment (below college vs college or above), annual income (<50,000 US$ vs ≥50,000 US$), tobacco use (non-smoker vs former and current smoker) and PASE score. We tested linear trends using the median value of each quartile of DII®as a continuous variable in the regression model. We conducted sensitivity analyses by including knee replacement due to knee OAduring the follow-up period as incident knee ROA or SxOA, respectively. We performed mediation analyses to assess mediation effect of BMI in DII®-OA relation. Results: We included 1786 and 2940 eligible participants in the final analyses for the association of DII®with incident knee ROA and SxOA, respectively (Figure 1). We identified 232 and 978 knees developed ROA and SxOA among eligible participants over 48-month follow-up period, respectively. Compared with the lowest quartile of DII®, odds ratio (OR) of incident ROA for the highest quartile of DII®was 1.73 (95% confidence interval (CI): 1.15 to 2.62, P for trend= 0.007) (Table 1). The corresponding OR of SxOA was 1.43 (95% CI: 1.16 to 1.76, P for trend = 0.001) (Table 1). When total knee replacement due to knee OA was counted as an incident case of either ROA or SxOA, the results did not change materially.The DII®-OA association was significantly mediated via BMI with an indirect effect of 1.05 (95% CI: 1.02,1.08) for ROA and 1.05 (95% CI: 1.05, 1.11) for SxOA, accounting for 15.6% and 36.0% of total effect, respectively (Table 2). Conclusions: A higher inflammatory potential of diet increased the risk of knee OA. The association was significantly mediated via BMI. A role of inflammatory potential in dietary strategy for OA was indicated.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Body Mass Index Mediates the Association between Dietary Fiber and Symptomatic Knee Osteoarthritis in the Osteoarthritis Initiative and the Framingham Osteoarthritis Study

Dietary fiber reduces body weight and inflammation in clinical trials. It is unclear whether body mass index (BMI) and inflammation might explain the observed association between higher fiber intake and the lower risk of symptomatic knee osteoarthritis (SXKOA). We quantified the extent to which BMI and inflammation influenced the relation between dietary fiber and SXKOA. We used longitudinal data from the Osteoarthritis Initiative (OAI) and the Framingham Offspring Osteoarthritis Study. At baseline of each study, men and women (mean age: 61 y) with or at risk of knee osteoarthritis were followed for 48 mo in the OAI. Adults (mean age: 53 y) were followed for 9.5 y in the Framingham study. Dietary fiber intake was estimated using a validated food-frequency questionnaire. Measured weight and height were used to calculate BMI. Serum high-sensitivity C-reactive protein (CRP) was measured in the Framingham study only. Incident SXKOA was defined as new onset of a combination of knee pain and radiographic osteoarthritis. We applied marginal structural models to quantify the mediation through BMI in the OAI and the sequential mediation through BMI and CRP in the Framingham study. Incident SXKOA occurred in 861 knees among 2876 persons in the OAI and in 143 knees among 971 persons in the Framingham study. In persons whose fiber intake was ≥21 g/d compared with those with intakes <21 g/d, the OR (95% CI) was 0.70 (0.53, 0.91) for the overall association with SXKOA and was 0.93 (0.92, 0.95) for the mediation via BMI (per kg/m2) in the OAI. In the Framingham study, the overall association was 0.57 (0.30, 1.09), the mediation through BMI (via BMI and the influence of BMI on CRP) was 0.94 (0.85, 1.02), and the mediation through CRP (per milligram per liter) was 0.99 (0.84, 1.19). Our findings suggest that the inverse association of fiber intake and the risk of incident symptomatic knee osteoarthritis is partially mediated by BMI.

Subjective Crepitus as a Risk Factor for Incident Symptomatic Knee Osteoarthritis: Data From the Osteoarthritis Initiative.

Subjective crepitus is the reporting of hearing grating, cracking, or popping sounds in and/or around a joint. We aimed to evaluate whether there is an association between crepitus and incident symptomatic knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), a multicenter longitudinal US cohort. Knees without baseline symptomatic OA were included. Crepitus frequency was assessed using a question from the Knee Injury and Osteoarthritis Outcome Score at baseline and at 12, 24, and 36 months. Frequent knee pain and radiographs were assessed at baseline and at annual visits up to 48 months. Radiographic OA was defined as a tibiofemoral Kellgren/Lawrence grade ≥2. Symptomatic OA was defined as a knee with both frequent symptoms and radiographic OA. We performed a repeated-measures analysis with a predictor of crepitus and outcome of incident symptomatic OA, adjusting for age, sex, and body mass index (BMI), with those never reporting crepitus as the referent group. There were a total of 3,495 participants (42.2% male), with mean ± SD age of 61.1 ± 9.2 years and a mean ± SD BMI of 28.2 ± 4.7 kg/m². The odds of incident symptomatic OA were higher with greater frequency of crepitus (never, rarely, sometimes, often, and always, with adjusted odds ratios of (referent), 1.5, 1.8, 2.2, and 3.0, respectively; P < 0.0001 for trend). The group with radiographic OA at OAI baseline but without symptoms contributed 26% of the observations but more than 75% of the incident symptomatic OA cases. In those without symptomatic OA, subjective knee crepitus predicts incident symptomatic OA longitudinally, with most cases occurring in those with preexisting tibiofemoral radiographic OA but without frequent knee pain. However, an important limitation is that patellofemoral OA was not systematically evaluated within the OAI. Subjective crepitus offers utility for the identification of at-risk individuals, predictive modeling, and future research.

Predictive Capacity of Thigh Muscle Strength in Symptomatic and/or Radiographic Knee Osteoarthritis Progression: Data from the Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium.

Thigh muscle weakness is a risk factor for incident radiographic and symptomatic knee osteoarthritis (KOA). The role of thigh muscle weakness in radiographic and/or symptomatic KOA progression remains elusive. Five hundred twenty-seven knees of 527 Osteoarthritis Initiative participants with baseline Kellgren-Lawrence grades 1 to 3 were included in this nested case-control study evaluating whether baseline muscle strength predicted symptomatic and/or radiographic KOA progression. Case knees (n = 173) displayed both medial tibiofemoral joint space loss (≥0.7 mm) and a persistent increase in Western Ontario McMasters Osteoarthritis Index pain (≥9 on a 0- to 100-point scale) over 24 to 48 months from baseline. Control knees (n = 354) included 174 with neither radiographic nor symptomatic progression, 91 with radiographic progression only, and 89 with symptomatic progression only. Isometric knee extensor and flexor strength were recorded at baseline. Using logistic regression models, muscle strength was not associated with case status. However, knee extensor (odds ratio, 1.7; 95% confidence interval, 1.1-3.3; P = 0.035) and flexor weakness (odds ratio, 2.0; 95% confidence interval, 1.1, 3.3; P = 0.016) predicted isolated symptomatic progression in males, but not in females. The results indicate that thigh muscle strength may affect symptomatic and structural progression differently in males with KOA and identify an important window for potentially lowering risk of symptomatic osteoarthritis progression in men.

Effect of Knee Extensor Strength on Incident Radiographic and Symptomatic Knee Osteoarthritis in Individuals With Meniscal Pathology: Data From the Multicenter Osteoarthritis Study.

High knee extensor strength may be important to protect against the development of knee osteoarthritis (OA) in populations at elevated risk, such as individuals with meniscal pathology. We investigated the extent to which high knee extensor muscle strength was associated with a decreased risk of developing radiographic or symptomatic knee OA in individuals with medial meniscal pathology. We studied knees that at the baseline visit of the Multicenter Osteoarthritis Study had medial meniscal pathology but did not have radiographic knee OA (373 knees in 373 participants) or symptomatic knee OA (combination of radiographic knee OA and frequent knee symptoms; 531 knees in 531 participants). Isokinetic knee extensor strength was measured at baseline, and participants were followed for development of incident radiographic knee OA or incident symptomatic knee OA at 84 months. Separate binomial regression analyses with robust SEs adjusted for age, history of knee surgery, physical activity level, and clinic site were conducted for men and women. High knee extensor strength (normalized by allometric scaling) was associated with a reduced risk of radiographic knee OA in women (relative risk [RR] 0.52, 95% confidence interval [95% CI] 0.29-0.94) but not in men (RR 0.56, 95% CI 0.27-1.16). High knee extensor strength did not protect against the development of symptomatic knee OA, either in women or men. The results only partly confirm the hypothesis that high knee extensor muscle strength protects against later development of knee OA in individuals with medial meniscal pathology.

Is waist circumference a better predictor of incident symptomatic radiographic knee osteoarthritis, radiographic knee osteoarthritis and knee pain than body mass index over 10 years?

Is waist circumference a better predictor of incident symptomatic radiographic knee osteoarthritis, radiographic knee osteoarthritis and knee pain than body mass index over 10 years?

Longitudinal Course of Physical Function in People With Symptomatic Knee Osteoarthritis: Data From the Multicenter Osteoarthritis Study and the Osteoarthritis Initiative.

Pain and functional decline are hallmarks of knee osteoarthritis (OA). Nevertheless, longitudinal studies unexpectedly reveal stable or improved physical function. The aim of this study was to impute missing and pre-total knee replacement (TKR) values to describe physical function over time among people with symptomatic knee OA. We included participants from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) with incident symptomatic knee OA, observed during the first 30 months in MOST and 36 months in OAI. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function (WOMAC-PF), the 5-times sit-to-stand test, and the 20-meter-walk test were assessed at 4 and 5 years in MOST and at 6 years in OAI. We used a multiple imputation method for missing visits, and estimated pre-TKR values close to the time of TKR, using a fitted local regression smoothing curve. In mixed-effect models, we investigated the physical function change over time, using data before and after imputation and calculation of pre-TKR values. In MOST, 225 (8%) had incident knee OA, with corresponding 577 (12.7%) in OAI. After adjusting for pre-TKR values and imputing missing values, we found that WOMAC-PF values remained stable or slightly declined over time, and the 20-meter-walk test results changed from stable in nonimputed analyses to worsening using imputed data. Data from MOST and OAI showed stable to worsening physical function over time in people with incident symptomatic knee OA after imputing missing values and adjusting pre-TKR values.

Association between knee extensor muscle strength and incident radiographic and symptomatic knee osteoarthritis in middle-aged or older adults with medial meniscal pathology: the most study

s / Osteoarthritis and Cartilage 22 (2014) S7–S56 S43 We then performed sensitivity analyses restricting to those with KL grade < 2 at baseline. Results: For the medial JSN analysis, 2424 people were included with a meanage of 59.5 (9.0) years,meanBMI of 27.7 (4.6) kg/m2, 39%weremale, 81% were white. For the lateral JSN analysis, 3905 people were included with ameanageof62.1 (9.1) years,meanBMIof 28.5 (4.8) kg/m2, 43%were male, 81%werewhite. Sensitivity analyses restricting to thosewith KL< 2 at baseline were similar to those reported in tables 1 and 2. Conclusions: This study identifies that PP and perhaps SBP are associated with incident radiographic medial TF OA. Because PP is known to be elevated when arteries are stiff, additional studies studying a possible relationship between elevated pulse pressure, arterial stiffness, and medial TF OA are warranted. Further study of underlying mechanisms to explainwhy PP and SBP may be associated with medial but not lateral TF OA is warranted. 66 ASSOCIATION BETWEEN KNEE EXTENSOR MUSCLE STRENGTH AND INCIDENT RADIOGRAPHIC AND SYMPTOMATIC KNEE OSTEOARTHRITIS IN MIDDLE-AGED OR OLDER ADULTS WITH MEDIAL MENISCAL PATHOLOGY: THE MOST STUDY J.B. Thorlund y, D.T. Felson z, N.A. Segal x, T. Neogi z, M.C. Nevitt k, C.E. Lewis{, J. Niu z, A. Guermazi z, F.W. Roemer z#, M. Englund zyy. yUniv. of Southern Denmark, Odense M, Denmark; zBoston Univ., Boston, MA, USA; xUniv. of Iowa, Iowa City, IA, USA; kUniv. of California at San Francisco, San Francisco, CA, USA; {Univ. of Alabama at Birmingham, Birmingham, AL, USA; Klinikum Augsburg, Augsburg, Germany; yy Lund Univ., Lund, Sweden Purpose: Patients with knee osteoarthritis (OA) often have impaired knee extensor strength. There is also evidence that high knee extensor strength may postpone or prevent knee OA development in the general population. Hypothetically, the importance of knee extensor strength maybe evenmore pronounced in subjects at high risk of kneeOA.Hence, our aim was to determine the association between knee extensor strength and incident radiographic whole knee OA (ROA) and incident symptomatic radiographic whole knee OA (SxOA) in participants with meniscal pathology. We hypothesized that higher baseline knee extensor strength would be associated with a lower risk for incident ROA and incident SxOA among those with pre-existing meniscal pathology. Table 2 Incident symptomatic whole knee osteoarthritis in persons with medial meniscal pathol

Risk factors for incident symptomatic knee osteoarthritis: A population-based case control study in Lebanon

To identify risk factors for symptomatic knee osteoarthritis (OA) and explain the geographical disparities in its occurrence. A population-based case control study used data from a national Community Oriented Program for the Control of Rheumatic Diseases (COPCORD) study conducted in Lebanon in 2009. The sample included 59 incident cases of symptomatic knee OA with no past knee injury, knee pain for a period of < 12 months, and were examined by rheumatologists. One hundred and eighteen randomly sampled population-based controls were frequency matched with cases by age and gender. Obesity, overweight and area of residence were significant risk factors for knee OA, after adjusting for type of job, monthly income and family history of joint problems. Determinants of symptomatic knee OA in Lebanon may differ by geographical location, potentially reflecting differences in social conditions, biological elements and environmental factors. The geographical differences remained significant even after accounting for investigated factors. Thus, further research is needed to explore other potential determinants, such as living conditions, biomechanical and hormonal factors.

Is Quadriceps Muscle Weakness a Risk Factor for Incident or Progressive Knee Osteoarthritis?

The role of the quadriceps muscle in mediating risk for knee osteoarthritis (OA) is a common subject of investigation. The quadriceps muscle is a principal contributor to knee joint stability and provides shock absorption for the knee during ambulation. Clinically, weakness of the quadriceps muscle is consistently found in patients with knee OA. Research has shown that higher quadriceps muscle strength is associated with a reduced risk for incident symptomatic knee OA. However, there is limited evidence to suggest that quadriceps muscle plays a significant role in the incidence of radiographic knee OA. In addition, greater quadriceps muscle strength is associated with a lower risk for progression of tibiofemoral joint space narrowing and cartilage loss in women. This article summarizes knowledge of the relationship between quadriceps muscle strength and risk for knee OA.