Acetabular dysplasia and the risk of developing hip osteoarthritis within 4-8 years: An individual participant data meta-analysis of 18,807 hips from the World COACH consortium.

Objective: To study the association between various radiographic definitions of acetabular dysplasia (AD) and incident radiographic hip osteoarthritis (RHOA), and to analyze in subgroups.

Methods: Hips free of RHOA at baseline and with follow-up within 4-8 years were drawn from the World COACH consortium. The Wiberg center edge angle (WCEA), acetabular depth width ratio (ADR), and the modified acetabular index (mAI) were calculated.

Comparison of definitions of early knee osteoarthritis for likelihood of progression at 2-year and 5-year follow-up: the Multicenter Osteoarthritis Study.

Background: Preventing worsening osteoarthritis (OA) in persons with early OA is a major treatment goal. We evaluated if different early OA definitions yielded enough cases of worsening OA within 2-5 years to make trial testing treatments feasible.

Methods: We assessed different definitions of early OA using data from Multicenter Osteoarthritis (MOST) Study participants who were followed up longitudinally.

Clinical and imaging findings associated with preservation of knee joint health over 8 years in individuals aged 65 and over: data from the OAI.

Objective: While risk factors for osteoarthritis (OA) are well known, it is not well understood why certain individuals maintain high mobility and joint health throughout their life while others demonstrate OA at older ages. The purpose of this study was to assess which demographic, clinical and MRI quantitative and semi-quantitative factors are associated with preserving healthy knees in older individuals.

Methods: This study analyzed data from the OA Initiative (OAI) cohort of individuals at the age of 65 years or above.

Associations of pain sensitivity and conditioned pain modulation with physical activity: findings from the Multicenter Osteoarthritis Study (MOST).

Objective: Individuals with chronic pain due to knee osteoarthritis (OA) are insufficiently physically active, and alterations of facilitatory and inhibitory nociceptive signaling are common in this population. Our objective was to examine the association of these alterations in nociceptive signaling with objective accelerometer-based measures of physical activity in a large observational cohort.

Design: We used data from the Multicenter Osteoarthritis Study.

Bicycling over a Lifetime Is Associated with Less Symptomatic Knee Osteoarthritis: Data from the Osteoarthritis Initiative.

Introduction: This study aimed to evaluate the relationship between a history of bicycling and symptomatic and structural outcomes of knee osteoarthritis (OA), the most common form of arthritis.

Methods: This was a retrospective, cross-sectional study within the Osteoarthritis Initiative (OAI), where we investigated OAI participants with complete data on bicycling, knee pain, and radiographic evidence of knee OA. We used a self-administered questionnaire at the 96-month OAI visit to identify participation in bicycling during four time periods throughout a participant's lifetime (ages 12-18, 19-34, 35-49, and >50 yr).

Gardening/yardwork in people with knee osteoarthritis is not associated with symptom or structural progression over 48 months: data from the Osteoarthritis Initiative.

Objective: To evaluate the relationship of gardening/yardwork with symptomatic and structural progression in those with pre-existing radiographic knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), an observational study designed to evaluate potential and known biomarkers and risk factors of knee OA.

Methods: We conducted a cohort study nested within the OAI, including participants ≥ 50 years old with radiographic OA in at least one knee at the time of OAI enrollment. A participant reported the level of gardening/yardwork activity in a self-administered survey.

Gait Alterations and Association With Worsening Knee Pain and Physical Function: A Machine Learning Approach With Wearable Sensors in the Multicenter Osteoarthritis Study.

Objective: The objective of this study was to identify gait alterations related to worsening knee pain and worsening physical function, using machine learning approaches applied to wearable sensor-derived data from a large observational cohort.

Methods: Participants in the Multicenter Osteoarthritis Study (MOST) completed a 20-m walk test wearing inertial sensors on their lower back and ankles. Parameters describing spatiotemporal features of gait were extracted from these data.

Intra-Articular Mineralization on Computerized Tomography of the Knee and Risk of Cartilage Damage: The Multicenter Osteoarthritis Study.

Objective: Intra-articular (IA) mineralization may contribute to osteoarthritis (OA) structural progression. We studied the association of IA mineralization on knee computed tomography (CT) with cartilage damage worsening on knee magnetic resonance imaging (MRI), with a focus on location- and tissue-specific effects.

Methods: Participants from the Multicenter Osteoarthritis Study with knee CT and MRI scans were included.

Assessing the association of epigenetic age acceleration with osteoarthritis in the Multicenter Osteoarthritis Study (MOST).

Purpose: Advancing age is one of the strongest risk factors for osteoarthritis (OA). DNA methylation-based measures of epigenetic age acceleration may provide insights into mechanisms underlying OA.

Methods: We analyzed data from the Multicenter Osteoarthritis Study in a subset of 671 participants ages 45-69 years with no or mild radiographic knee OA.

Essential Fatty Acids and Osteoarthritis.

Objective: 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.

Thigh muscle and fat volumes are associated with knee cartilage abnormalities and bone marrow edema-like lesions: data from the osteoarthritis initiative.

Objective: To investigate the associations of thigh muscle and fat volumes with structural abnormalities on MRI related to knee osteoarthritis.

Materials And Methods: MRI studies of the thighs and knees from 100 individuals were randomly selected from the Osteoarthritis Initiative Cohort. Whole Organ MR Scoring (WORMS) and effusion-synovitis scoring were performed in all knee MRI.

Strength Training Is Associated With Less Knee Osteoarthritis: Data From the Osteoarthritis Initiative.

Objective: We aimed to evaluate the relationship of a history of strength training with symptomatic and structural outcomes of knee osteoarthritis (OA).

Methods: This study was a retrospective, cross-sectional study within the Osteoarthritis Initiative (OAI), a multicenter prospective longitudinal observational study. Data were collected at four OAI clinical sites: Memorial Hospital of Rhode Island, the Ohio State University, the University of Pittsburgh, and the University of Maryland/Johns Hopkins.

Mediating Effect of Pain Sensitization on the Paradoxical Relation of Taking Opioids to Pain Severity in Knee Osteoarthritis: The Multicenter Osteoarthritis Study.

Objective: One of the less understood adverse effects while taking opioids is the paradoxical increase in pain, known as opioid-induced hyperalgesia (OIH). We sought to determine whether pain sensitization mediates the relation of taking an opioid to pain severity in people with knee osteoarthritis (OA).

Methods: We included participants in a National Institutes of Health-funded cohort study of people with or at risk of knee OA.

Association of Medial Meniscus Root Tears and Nonroot Tears With Worsening of Radiographic Knee Osteoarthritis.

Background: Medial meniscus root tears (RTs) are associated with the development and worsening of knee osteoarthritis (OA), but little is known about their progression when compared with meniscal tears that spare the root (nonroot tears; NRTs).

Purpose: To compare radiographic worsening of OA in knees with RTs versus NRTs and to identify factors associated with radiographic worsening of OA in knees with RTs.

Study Design: Cohort study; Level of evidence, 3.

Exploring different models of pain phenotypes and their association with pain worsening in people with early knee osteoarthritis: The MOST cohort study.

Objective: To determine i) pain phenotypes (PP) in people with early-stage knee osteoarthritis (EKOA); ii) the longitudinal association between the phenotypes and pain worsening at two years.

Design: We studied participants with EKOA from the Multicenter Osteoarthritis Study defined as pain intensity ≤3/10, Kellgren and Lawrence grade ≤2, intermittent pain none to sometimes, and no constant pain. Two models of PP were explored.

Associations between weight change, knee subcutaneous fat and cartilage thickness in overweight and obese individuals: 4-Year data from the osteoarthritis initiative.

Objective: To assess (i) the impact of changes in body weight on changes in joint-adjacent subcutaneous fat (SCF) and cartilage thickness over 4 years and (ii) the relation between changes in joint-adjacent SCF and knee cartilage thickness.

Design: Individuals from the Osteoarthritis Initiative (total=399) with > 10% weight gain (n=100) and > 10% weight loss (n=100) over 4 years were compared to a matched control cohort with less than 3% change in weight (n=199). 3.

Relation of Intra-Articular Mineralization to Knee Pain in Knee Osteoarthritis: A Longitudinal Analysis in the MOST Study.

Objective: Intra-articular (IA) calcium crystal deposition is common in knee osteoarthritis (OA), but of unclear significance. It is possible that low-grade, crystal-related inflammation may contribute to knee pain. We examined the longitudinal relation of computed tomography (CT)-detected IA mineralization to the development of knee pain.

Hip Abductor Weakness and Its Association With New or Worsened Knee Pain: Data From the Multicenter Osteoarthritis Study.

Objective: Hip abductors, important for controlling pelvic and femoral orientation during gait, may affect knee pain. Our objective was to evaluate the relation of hip abductor strength to worsened or new-onset frequent knee pain. Given previously noted associations of knee extensor strength with osteoarthritis in women, we performed sex-specific analyses.

Gait, physical activity and tibiofemoral cartilage damage: a longitudinal machine learning analysis in the Multicenter Osteoarthritis Study.

Objective: To (1) develop and evaluate a machine learning model incorporating gait and physical activity to predict medial tibiofemoral cartilage worsening over 2 years in individuals without advanced knee osteoarthritis and (2) identify influential predictors in the model and quantify their effect on cartilage worsening.

Design: An ensemble machine learning model was developed to predict worsened cartilage MRI Osteoarthritis Knee Score at follow-up from gait, physical activity, clinical and demographic data from the Multicenter Osteoarthritis Study. Model performance was evaluated in repeated cross-validations.

Post-surgical contributors to persistent knee pain following knee replacement: The Multicenter Osteoarthritis Study (MOST).

Objective: Pain persistence following knee replacement (KR) occurs in ∼20-30% of patients. Although several studies have identified preoperative risk factors for persistent post-KR pain, few have focused on post-KR contributing factors. We sought to determine whether altered nociceptive signaling and other peripheral nociceptive drivers present post-operatively contribute to post-KR pain.

The Association of Metabolic Syndrome and Obesity With Clinical Hip Osteoarthritis in the Study of Osteoporotic Fractures and the Osteoporotic Fractures in Men Study Cohorts.

Objective: Metabolic dysregulation frequently co-occurs with obesity, which has been shown to be a risk factor for lower extremity osteoarthritis (OA). We evaluated the association between metabolic syndrome (MetS), alone and in combination with obesity, and hip OA.

Methods: In two parallel cross-sectional analyses, we studied 403 women from the Study of Osteoporotic Fractures (SOF) and 2354 men from the Osteoporotic Fractures in Men (MrOS) study.

Development of a Magnetic Resonance Imaging-Based Definition of Knee Osteoarthritis: Data From the Multicenter Osteoarthritis Study.

Objective: Although magnetic resonance imaging (MRI) is the imaging modality of choice for research, there is no widely accepted MRI definition of knee osteoarthritis (OA). We undertook this study to test the performance of different MRI definitions of OA.

Methods: We studied Multicenter Osteoarthritis Study participants with knee symptoms using posteroanterior and lateral knee radiographs and MRIs.

The effect of interactions between BMI and sustained depressive symptoms on knee osteoarthritis over 4 years: data from the osteoarthritis initiative.

Background: To assess the compound effects of BMI and sustained depressive symptoms on changes in knee structure, cartilage composition, and knee pain over 4 years using statistical interaction analyses.

Methods: One thousand eight hundred forty-four individuals from the Osteoarthritis Initiative Database were analyzed at baseline and 4-year follow-up. Individuals were categorized according to their BMI and presence of depressive symptoms (based on the Center for Epidemiological Studies Depression Scale (threshold≥16)) at baseline and 4-year follow-up.