Do Existing MRI Definitions of Knee Osteoarthritis Identify Knees That Will Develop Clinically Significant Disease Over Up To 11 Years of Follow-Up?

Objective: In individuals without radiographic knee osteoarthritis (OA), we investigated whether magnetic resonance imaging (MRI)-defined knee OA at baseline was associated with incident radiographic and symptomatic disease during up to 11 years of follow-up.

Methods: Osteoarthritis Initiative participants without tibiofemoral radiographic knee OA at baseline were assessed for MRI-based tibiofemoral cartilage damage, osteophyte presence, bone marrow lesions, and meniscal damage/extrusion. We defined MRI knee OA using alternative, reported definitions (Def A and Def B).

The Natural History of Knee Osteoarthritis Pain Experience and Risk Profiles.

The study aimed to characterize the natural history of the pain experience, concurrently considering intermittent and constant pain over 4 years, and determine baseline factors associated with unfavorable trajectories in individuals with chronic knee pain. The Osteoarthritis Initiative (OAI) is a prospective, observational study of people with or at higher risk for knee osteoarthritis. The Intermittent and Constant Osteoarthritis Pain (ICOAP) was assessed annually at 48-to-96-month OAI visits.

Ambulatory support moment contribution patterns and MRI-detected tibiofemoral and patellofemoral disease worsening in adults with knee osteoarthritis: A preliminary study.

We investigated whether baseline sagittal-plane ankle, knee, and hip contribution to the total support moment (TSM) are each associated with baseline-to-2-year tibiofemoral and patellofemoral tissue damage worsening in adults with knee osteoarthritis. Ambulatory lower-limb kinetics were captured and computed. TSM is the sum of ankle, knee, and hip extensor moments at each instant during gait.

The Association Between Severity of Radiographic Knee OA and Recurrent Falls in Middle and Older Aged Adults: The Osteoarthritis Initiative.

Background: Knee osteoarthritis (KOA) is the most prevalent type of OA and a leading cause of disability in the United States. Falls are a major public health concern in older adults. Our aim was to examine how the severity of radiographic KOA affects recurrent falls in a cohort of middle-aged and older individuals enrolled in the Osteoarthritis Initiative.

Longitudinal Relationship Between Tibiofemoral Contact Stress at Baseline and Worsening of Knee Pain Over 84 Months in the Multicenter Osteoarthritis Study.

Objective: The aim of the study was to determine whether tibiofemoral contact stress predicts risk for worsening knee pain over 84 ms in adults aged 50-79 yrs with or at elevated risk for knee osteoarthritis.

Design: Baseline tibiofemoral contact stress was estimated using discrete element analysis. Other baseline measures included weight, height, hip-knee-ankle alignment, Kellgren-Lawrence grade, and Western Ontario and McMaster Universities Osteoarthritis Index pain subscale.

Knee Confidence Trajectories Over Eight Years and Factors Associated With Poor Trajectories in Individuals With or at Risk for Knee Osteoarthritis.

Objective: To identify distinct trajectories of lack of knee confidence over an 8-year follow-up period and to examine baseline factors associated with poor trajectories in individuals with or at risk for knee osteoarthritis (OA).

Methods: The Osteoarthritis Initiative is a prospective cohort study of individuals with or at high risk for knee OA. Confidence in the knees was assessed within the Knee Injury and Osteoarthritis Outcome Score instrument querying how much the individual is troubled by lack of confidence in his/her knee(s), rated as not-at-all (score = 0), mildly (score = 1), moderately (score = 2), severely (score = 3), and extremely (score = 4) troubled, reported annually from baseline to 96 months.

Is Laminar Cartilage Composition as Determined by T2 Relaxometry Associated with Incident and Worsening of Cartilage or Bone Marrow Abnormalities?

Objective: To test the hypothesis that superficial cartilage composition (T2) is associated with subsequent incidence or worsening of cartilage damage, and deep T2 with that of bone marrow lesions (BMLs) in knees without radiographic osteoarthritis (ROA).

Design: A total of 201 knees from the Osteoarthritis Initiative without ROA were included: 78 from the healthy reference cohort, 60 without ROA but with risk factors, and 63 without ROA but with contralateral ROA. Year 1 (Y1) superficial and deep cartilage T2 were derived in the medial and lateral (weightbearing) femur (MF/LF) and tibia (MT/LT), using sagittal multiecho spin echo magnetic resonance images.

Association of Long-term Strenuous Physical Activity and Extensive Sitting With Incident Radiographic Knee Osteoarthritis.

Importance: Persons with knee symptoms recognize the health benefits of engaging in physical activity, but uncertainty persists about whether regular strenuous physical activity or exercise can accelerate tissue damage. A sedentary lifestyle of inactivity or underloading may also be associated with deleterious joint health.

Objective: To establish whether long-term strenuous physical activity participation and extensive sitting behavior are each associated with increased risk of developing radiographic knee osteoarthritis (KOA) in individuals at high risk for the disease.

Frequencies of MRI-detected structural pathology in knees without radiographic OA and worsening over three years: How relevant is contralateral radiographic osteoarthritis?

Purpose: To test whether radiographically normal knees with contralateral radiographic knee osteoarthritis (ROA) (i.e. 'early OA model') exhibit MRI-defined structural tissue pathology to a greater extent and show higher rates of progression compared to knees with bilateral radiographically normal knees without risk factors ('healthy reference').

Development and validation of risk stratification trees for incident slow gait speed in persons at high risk for knee osteoarthritis.

Objectives: Disability prevention strategies are more achievable before osteoarthritis disease drives impairment. It is critical to identify high-risk groups, for strategy implementation and trial eligibility. An established measure, gait speed is associated with disability and mortality.

One Hour a Week: Moving to Prevent Disability in Adults With Lower Extremity Joint Symptoms.

Introduction: Physical activity guidelines recommend minimum thresholds. This study sought to identify evidence-based thresholds to maintain disability-free status over 4years among adults with lower extremity joint symptoms.

Methods: Prospective multisite Osteoarthritis Initiative accelerometer monitoring cohort data from September 2008 through December 2014 were analyzed.

Association of Varus Knee Thrust During Walking With Worsening Western Ontario and McMaster Universities Osteoarthritis Index Knee Pain: A Prospective Cohort Study.

Objective: To investigate the 2-year association of varus knee thrust observed during walking to the odds of worsening Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain in older adults with or at risk of osteoarthritis (OA).

Methods: Video recordings of self-paced walking trials of Multicenter Osteoarthritis Study participants were assessed for the presence of varus thrust at baseline. Knee pain was assessed using the WOMAC questionnaire at baseline and at 2 years.

Physical Activity and Worsening of Radiographic Findings in Persons With or at Higher Risk of Knee Osteoarthritis.

Objective: The benefits of physical activity among persons with or at higher risk for knee osteoarthritis are well established. However, activity levels in this population are low, in part due to concern that activity will damage the knee joint. We hypothesized that sedentary and moderate-vigorous physical activity are each associated with greater risk of radiographic worsening of knee OA.

Organizing seniors to protect the health safety net: the way forward.

Over the past century, the organized voice of seniors has been critical in building the U.S. health safety net.

Varus Thrust and Incident and Progressive Knee Osteoarthritis.

Objective: To determine if varus thrust, a bowing out of the knee during gait (i.e., the first appearance or worsening of varus alignment during stance), is associated with incident and progressive knee osteoarthritis (OA), we undertook an Osteoarthritis Initiative ancillary study.

Do Inactive Older Adults Who Increase Physical Activity Experience Less Disability: Evidence From the Osteoarthritis Initiative.

Background: Physical inactivity is a leading risk factor for developing disability. Although randomized clinical trials have demonstrated improving physical activity can reduce this risk in older adults with arthritis, these studies did not specifically evaluate inactive adults.

Objectives: The aim of this study was to evaluate the relationship of changes in physical activity with disability changes among initially inactive adults with or at high risk of knee osteoarthritis from Osteoarthritis Initiative.

Clinical significance of worsening versus stable preradiographic MRI lesions in a cohort study of persons at higher risk for knee osteoarthritis.

Background: Whether preradiographic lesions in knees at risk for osteoarthritis are incidental versus disease is unclear. We hypothesised, in persons without but at higher risk for knee osteoarthritis, that: 12-48 month MRI lesion status worsening is associated with 12-48 month incident radiographic osteoarthritis (objective component of clinical definition of knee osteoarthritis) and 48-84 month persistent symptoms.

Methods: In 849 Osteoarthritis Initiative participants Kellgren/Lawrence (KL) 0 in both knees, we assessed cartilage damage, bone marrow lesions (BMLs), and menisci on 12 month (baseline) and 48 month MRIs.

Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative.

Objective: To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement.

Methods: Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI.

Knee Instability and Basic and Advanced Function Decline in Knee Osteoarthritis.

Objective: Manifestations of instability in knee osteoarthritis (OA) include low overall knee confidence, low confidence that the knees will not buckle, buckling, and excessive motion during gait. Confidence and buckling may particularly influence activity choices, contributing to events leading to disability. Buckling is more likely to affect advanced than basic functional tasks.

Sedentary behavior and physical function: objective evidence from the Osteoarthritis Initiative.

Objective: Investigate the relationship between sedentary behavior and physical function in adults with knee osteoarthritis (OA), controlling for moderate-vigorous physical activity (MVPA) levels.

Methods: Sedentary behavior was objectively measured by accelerometer on 1,168 participants ages 49-83 years in the Osteoarthritis Initiative with radiographic knee OA at the 48-month clinic visit. Physical function was assessed using 20-meter walk and chair stand testing.