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. Twenty-eight baseline sociodemographic, knee-specific, and health-related characteristics were assessed. Group-based dual-trajectory modeling identified pain experience patterns indicated by ICOAP intermittent and constant pain scores over 4 years. Multivariable multinomial logistic regression models determined baseline factors associated with membership in each dual-trajectory group. Four longitudinal pain experience patterns were identified (n = 3,584, mean age = 64.8 [standard deviation 9.0] years, BMI = 28.6 [5.0] kg/m2; 57.9% women). Group 1 (37.7%) had minimal intermittent and no constant pain; Group 2 (35.1%) had mild intermittent and no constant pain; Group 3 (18.5%) had mild intermittent and low-grade constant pain; and Group 4 (8.7%) had moderate intermittent and constant pain. Baseline widespread pain, knee stiffness, back pain, hip pain, ankle pain, obesity, depressive symptoms, more advanced radiographic disease, and analgesic use were each associated with an increased risk of membership in less favorable Groups 2, 3, and 4. These distinct courses of pain experience may be driven by different underlying pain mechanisms. The benchmarked ICOAP scores could be used to stratify patients and tailor management. Addressing and preventing the development of modifiable risks (eg, widespread pain and knee joint stiffness) may reduce the chance of belonging to unfavorable dual-trajectory groups. PERSPECTIVE: Concurrently tracking intermittent versus constant pain experience, group-based dual-trajectory modeling identified 4 distinct pain experience patterns over 4 years. The benchmarked ICOAP scores in these dual trajectories could aid in stratifying patients for tailored management strategies and intensity of care.

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. Ankle, knee, and hip contributions to TSM were computed as joint moments divided by TSM, expressed as percentages. Participants underwent MRI of both knees at baseline and 2 years later. Logistic regression models assessed associations of baseline ankle contribution to TSM with baseline-to-2-year cartilage damage and bone marrow lesion worsening, adjusted for age, sex, BMI, gait speed, disease severity, and pain. We used similar analytic approaches for knee and hip contributions to TSM. Sample included 391 knees from 204 persons (age[SD]: 64[10] years; 76.5% women). Greater ankle contribution may be associated with increased odds of tibiofemoral cartilage damage worsening (OR = 2.38; 95% CI: 1.02-5.57) and decreased odds of patellofemoral bone marrow lesion worsening (OR = 0.14; 95% CI: 0.03-0.73). The ORs for greater knee contribution were in the protective range for tibiofemoral compartment and in the deleterious range for patellofemoral. Greater hip contribution may be associated with increased odds of tibiofemoral worsening (OR = 2.71; 95% CI: 1.17-6.30). Greater ankle contribution to TSM may be associated with baseline-to-2-year tibiofemoral worsening, but patellofemoral tissue preservation. Conversely, greater knee contribution may be associated with patellofemoral worsening, but tibiofemoral preservation. Preliminary findings illustrate potential challenges in developing biomechanical interventions beneficial to both tibiofemoral and patellofemoral compartments.

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. Lack of knee confidence was defined as a score of ≥2. We used latent class models to identify subgroups that share similar underlying knee confidence trajectories over an 8-year period and multivariable multinomial logistic regression models to examine baseline factors associated with poor trajectories. RESULTS: Among 4,515 participants (mean ± SD age 61.2 ± 9.2 years, mean ± SD BMI 28.6 ± 4.8 kg/m2 ; 2,640 [58.5%] women), 4 distinct knee confidence trajectories were identified: persistently good (65.6%); declining (9.1%); poor, improving (13.9%); and persistently poor (11.4%). Baseline predictors associated with persistently poor confidence (reference: persistently good) were younger age, male sex, higher body mass index (BMI), depressive symptoms, more advanced radiographic disease, worse knee pain, weaker knee extensors, history of knee injury and surgery, and reported hip and/or ankle pain. CONCLUSION: Findings suggest the dynamic nature of self-reported knee confidence and that addressing modifiable factors (e.g., BMI, knee strength, depressive symptoms, and lower extremity pain) may improve its long-term course.

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. Design, Setting, and Participants: This cohort study analyzed data from the Osteoarthritis Initiative, a prospective longitudinal cohort study of men and women with or at an increased risk of developing symptomatic, radiographic KOA. Community-dwelling adults were recruited from 4 US sites (Baltimore, Maryland; Columbus, Ohio; Pittsburgh, Pennsylvania; and Pawtucket, Rhode Island) and were followed up for up to 10 years. Individuals were included if they had a baseline Kellgren and Lawrence grade of 0 in both knees and completed a PASE (Physical Activity Scale for the Elderly) questionnaire at baseline and at least 2 follow-up visits over an 8-year interval. Data analyses were conducted from May 2018 to November 2018. Exposures: Baseline to 8-year trajectories of strenuous physical activity participation and extensive sitting behavior were identified using group-based trajectory models. Main Outcomes and Measures: Incident radiographic KOA, defined as Kellgren and Lawrence grade 2 or higher in either knee by the 10-year follow-up visit. Results: A total of 1194 participants were included in the sample (697 women [58.4%]), with a baseline mean (SD) age of 58.4 (8.9) years and mean body mass index (BMI) of 26.8 (4.5). Four distinct trajectories of weekly hours spent in strenuous physical activities and 3 distinct trajectories of extensive sitting were identified. Long-term engagement in low-to-moderate physical activities (adjusted odds ratio [OR], 0.69; 95% CI, 0.48-1.01) or any strenuous physical activities (adjusted OR, 0.75; 95% CI, 0.53-1.07) was not associated with 10-year incident radiographic KOA. Persistent extensive sitting was not associated with incident KOA. Despite relatively mild symptoms and high function in this early-stage sample, 594 participants (49.7%) did not engage in any strenuous physical activities (ie, 0 h/wk) across 8 years, and 507 (42.5%) engaged in persistent moderate-to-high frequency of extensive sitting. Older age, higher BMI, more severe knee pain, non-college graduate educational level, weaker quadriceps, and depression were each associated with a persistent lack of engagement in strenuous physical activities. Conclusions and Relevance: Results from this study appeared to show no association between long-term strenuous physical activity participation and incident radiographic KOA. The findings raise the possibility of a protective association between incident KOA and a low-to-moderate level of strenuous physical activities.

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. We sought to develop and validate risk stratification trees for incident slow gait in persons at high risk for knee osteoarthritis, feasible in community and clinical settings. METHODS: Osteoarthritis Initiative (derivation cohort) and Multicenter Osteoarthritis Study (validation cohort) participants at high risk for knee osteoarthritis were included. Outcome was incident slow gait over up to 10-year follow-up. Derivation cohort classification and regression tree analysis identified predictors from easily assessed variables and developed risk stratification models, then applied to the validation cohort. Logistic regression compared risk group predictive values; area under the receiver operating characteristic curves (AUCs) summarised discrimination ability. RESULTS: 1870 (derivation) and 1279 (validation) persons were included. The most parsimonious tree identified three risk groups, from stratification based on age and WOMAC Function. A 7-risk-group tree also included education, strenuous sport/recreational activity, obesity and depressive symptoms; outcome occurred in 11%, varying 0%-29 % (derivation) and 2%-23 % (validation) depending on risk group. AUCs were comparable in the two cohorts (7-risk-group tree, 0.75, 95% CI 0.72 to 0.78 (derivation); 0.72, 95% CI 0.68 to 0.76 (validation)). CONCLUSIONS: In persons at high risk for knee osteoarthritis, easily acquired data can be used to identify those at high risk of incident functional impairment. Outcome risk varied greatly depending on tree-based risk group membership. These trees can inform individual awareness of risk for impaired function and define eligibility for prevention trials.

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. We further considered hypothesized associations adjusted for static alignment, anticipating some attenuation. METHODS: Gait was observed for the presence of thrust by 1 of 2-3 examiners per study site at 4 sites. In eligible knees, incident OA was defined as subsequent incident Kellgren/Lawrence grade ≥2, whole- and partial-grade medial joint space narrowing (JSN), and annualized loss of joint space width (JSW); progression was defined as medial JSN and JSW loss. Outcome measures were assessed for up to 7 years of follow-up. Analyses were knee-level, using multivariable logistic and linear regression with generalized estimating equations to account for between-limb correlation. RESULTS: The incident OA sample included 4,187 knees (2,610 persons); the progression sample included 3,421 knees (2,284 persons). In knees with OA, thrust was associated with progression as assessed by each outcome measure, with adjustment for age, sex, body mass index, and pain on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. In knees without OA, varus thrust was not associated with incident OA or other outcomes. After adjustment for alignment, the thrust-progression association was attenuated, but an independent association persisted for partial-grade JSN and JSW loss outcome models. WOMAC pain and alignment were consistently associated with all outcome measures. Within the stratum of varus knees, thrust was associated with an increased risk of progression. CONCLUSION: Varus thrust visualized during gait is associated with knee OA progression and should be a target of intervention development.

Impact of urinary incontinence on medical rehabilitation inpatients.

AIMS: To determine the prevalence of urinary incontinence (UI) and its association with rehabilitation outcomes in patients receiving inpatient medical rehabilitation in the United States. METHODS: A retrospective, cohort study of 425,547 Medicare patients discharged from inpatient rehabilitation facilities (IRFs) in 2005. We examined prevalence of UI at admission and discharge for 5 impairment groups. We examined the impact of demographics, health, and functional status on the primary outcome, change in continence status, and secondary outcomes of discharge location and 6-month mortality. RESULTS: Approximately one-quarter (26.6%) of men were incontinent at admission compared to 22.2% of women. In all diagnostic groups, continence status remains largely unchanged from admission to discharge. Patients who are older, have cognitive difficulties, less functional improvement, and longer lengths of stay (LOS), are more likely to remain incontinent, compared to those who improved, after controlling for patient factors and clinical variables. UI was significantly associated with discharge to another post-acute setting (PAC). For orthopedic patients, UI was associated with a 71% increase in the likelihood of discharge to an institutional setting after controlling for patient factors and clinical variables. UI was not associated with death at 6 months post-discharge. CONCLUSIONS: UI is highly prevalent in IRF patients and is associated with increased likelihood of discharge to institutional care, particularly for orthopedic patients. Greater attention to identifying and treating UI in IRF patients may reduce medical expenditures and improve other outcomes. Neurourol. Urodynam. 36:176-183, 2017. © 2015 Wiley Periodicals, Inc.

Esophageal dilatation and interstitial lung disease in systemic sclerosis: A cross-sectional study.

OBJECTIVE: A patulous esophagus on high-resolution computed tomography (HRCT) of the thorax is frequently observed in patients with systemic sclerosis (SSc). Microaspiration has been purported to play a role in the development and progression of SSc interstitial lung disease (ILD), but studies examining the role of microaspiration in SSc ILD have yielded conflicting results. This study was conducted to determine the association between esophageal diameter and SSc ILD. METHODS: A cross-sectional study of Northwestern Scleroderma Registry patients with available HRCT exams was conducted. The predictor variable was the widest esophageal diameter (WED) on HRCT, and the primary and secondary outcome variables were radiographic ILD and pulmonary function tests respectively. The degree of radiographic ILD was assessed using a semi-quantitative score adapted from published methods. Estimated regression coefficients adjusted for age, sex, race, body mass index, smoking; SSc disease subtype, serum autoantibodies, and disease duration; modified Rodnan skin score, proton pump inhibitor, and immune suppressant medication use and erythrocyte sedimentation rate were calculated. RESULTS: A total of 270 subjects were studied. In the adjusted analyses, there were positive associations between WED and total ILD score (ß = 0.27; 95% CI: 0.09-0.41), fibrosis (ß = 0.15; 95% CI: 0.07-0.23), and ground glass opacities (ß = 0.12; 95% CI: 0.04-0.20); there were negative associations between WED and FVC % predicted (ß = -0.42; 95% CI: -0.69 to -0.13), and adjusted DLCO % predicted (ß = -0.45; 95% CI: -0.80 to -0.09) after adjusting for potential confounders. CONCLUSIONS: Increasing esophageal diameter on HRCT in patients with SSc is associated with more severe radiographic ILD, lower lung volumes, and lower DLCO % predicted. Longitudinal studies are needed to determine if esophageal dilatation is associated with the incidence and/or progression of ILD in patients with SSc.

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. Multivariable logistic regression was used to evaluate associations between 12-48 month worsening versus stable status and outcome (12-48 month incident KL ≥1 and KL ≥2, and 48-84 month persistent symptoms defined as frequent symptoms or medication use most days of ≥1 month in past 12 month, at consecutive visits 48-84 months), adjusting for age, gender, body mass index (BMI), injury and surgery. RESULTS: Mean age was 59.6 (8.8), BMI 26.7 (4.2) and 55.9% were women. 12-48 month status worsening of cartilage damage, meniscal tear, meniscal extrusion, and BMLs was associated with 12-48 month incident radiographic outcomes, and worsening of cartilage damage and BMLs with 48-84 month persistent symptoms. There was a dose-response association for magnitude of worsening of cartilage damage, meniscal tear, meniscal extrusion, and BMLs and radiographic outcomes, and cartilage damage and BMLs and persistent symptoms. CONCLUSIONS: In persons at higher risk, worsening MRI lesion status was associated with concurrent incident radiographic osteoarthritis and subsequent persistent symptoms. These findings suggest that such lesions represent early osteoarthritis, and add support for a paradigm shift towards investigation of intervention effectiveness at this stage.

Molecular characterization of systemic sclerosis esophageal pathology identifies inflammatory and proliferative signatures.

INTRODUCTION: Esophageal involvement in patients with systemic sclerosis (SSc) is common, but tissue-specific pathological mechanisms are poorly understood. There are no animal scleroderma esophagus models and esophageal smooth muscle cells dedifferentiate in culture prohibiting in vitro studies. Esophageal fibrosis is thought to disrupt smooth muscle function and lead to esophageal dilatation, but autopsy studies demonstrate esophageal smooth muscle atrophy and the absence of fibrosis in the majority of SSc cases. Herein, we perform a detailed characterization of SSc esophageal histopathology and molecular signatures at the level of gene expression. METHODS: Esophageal biopsies were prospectively obtained during esophagogastroduodenoscopy in 16 consecutive SSc patients and 7 subjects without SSc. Upper and lower esophageal biopsies were evaluated for histopathology and gene expression. RESULTS: Individual patient's upper and lower esophageal biopsies showed nearly identical patterns of gene expression. Similar to skin, inflammatory and proliferative gene expression signatures were identified suggesting that molecular subsets are a universal feature of SSc end-target organ pathology. The inflammatory signature was present in biopsies without high numbers of infiltrating lymphocytes. Molecular classification of esophageal biopsies was independent of SSc skin subtype, serum autoantibodies and esophagitis. CONCLUSIONS: Proliferative and inflammatory molecular gene expression subsets in tissues from patients with SSc may be a conserved, reproducible component of SSc pathogenesis. The inflammatory signature is observed in biopsies that lack large inflammatory infiltrates suggesting that immune activation is a major driver of SSc esophageal pathogenesis.

Survival in systemic sclerosis-pulmonary arterial hypertension by serum autoantibody status in the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) Registry.

OBJECTIVE: To determine the association between serum autoantibodies and survival in patients with incident systemic sclerosis (SSc)-pulmonary arterial hypertension (PAH) enrolled in the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) Registry. METHODS: Patients with definite PAH diagnosed by right heart catheterization within 6 months of registry enrollment were studied. Serum autoantibodies were assayed at each participating institution's clinical laboratory. Mortality data were collected from electronic medical records and/or the Social Security Death Index. Kaplan-Meier survival estimates were reported for five autoantibody groups (anticentromere/AC, nucleolar ANA/NUC, anti-topoisomerase/Scl-70, overlapping or non-specific autoantibodies/other, and a combined group with similar survival consisting of RNA polymerase III, U1RNP, and autoantibody-negative patients). Cox proportional hazards models permitted examination of the association between autoantibody groups and overall survival, controlling for age, sex, race, and SSc disease duration. RESULTS: In all, 162 subjects had PAH, and serum autoantibody and survival information; 60 (37%) had AC, 39 (24%) NUC, 11 (7%) Scl-70, 28 (17%) had other, 9 (6%) RNA pol, 8 (5%) U1RNP autoantibodies, and 7 (4%) had negative antibodies; 32 (20%) subjects died over a median follow-up time of 2.1 years (range: 0.01-6.8); 1- and 3-year survival estimates were, respectively, 94% and 78% for AC, 94% and 72% for NUC, 89% and 63% for Scl-70, 92% and 79% for the other group, and 100% and 93% for the combined group. Unadjusted and adjusted hazard ratios revealed no statistically significant association between risk of death and autoantibodies. CONCLUSION: Anticentromere and NUC autoantibodies are prevalent in SSc-PAH patients. An association between serum autoantibodies and survival in patients with SSc-PAH was not identified in the PHAROS cohort.

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. In this prospective longitudinal study, we tested the hypothesis that overall knee confidence, buckling confidence, buckling, and frontal plane motion during gait are associated with advanced 2-year function outcomes in persons with knee OA. METHODS: Persons with knee OA were queried about overall knee confidence (higher score = worse confidence), buckling confidence, and knee buckling, and underwent quantitative gait analysis to quantify varus-valgus excursion and angular velocity. Physical function was assessed using the Late-Life Function and Disability Instrument Basic and Advanced Lower Extremity Domain scores. Logistic regression was used to evaluate the relationship between baseline instability measures and baseline-to-2-year function outcome, adjusting for potential confounders. RESULTS: The sample was comprised of 212 persons (mean age 64.6 years, 76.9% women). Buckling was significantly associated with poor advanced function outcome (adjusted odds ratio [OR] 2.08, 95% confidence interval [95% CI] 1.03-4.20) but not basic function outcome. Overall knee confidence was significantly associated with advanced outcome (adjusted OR 1.65, 95% CI 1.01-2.70), while associations between buckling confidence and both outcomes approached significance. Neither varus-valgus excursion nor angular velocity during gait was associated with either outcome. CONCLUSION: Knee buckling and low knee confidence were each associated with poor 2-year advanced function outcomes. Current treatment does not address these modifiable factors; interventions to address them may improve outcome in knee OA.

Factors associated with pain experience outcome in knee osteoarthritis.

OBJECTIVE: Few strategies to improve pain outcome in knee osteoarthritis (OA) exist in part because how best to evaluate pain over the long term is unclear. Our objectives were to determine the frequency of a good pain experience outcome based on previously formulated OA pain stages and test the hypothesis that less depression and pain catastrophizing and greater self-efficacy and social support are each associated with greater likelihood of a good outcome. METHODS: Study participants, all with knee OA, reported pain stage at baseline and 2 years. Baseline assessments utilized the Geriatric Depression Scale, Pain Catastrophizing Scale, Arthritis Self-Efficacy Scale, and Medical Outcomes Study social support survey. Using pain experience stages, good outcome was defined as persistence in or movement to no pain or stage 1 (predictable pain, known trigger) at 2 years. A multivariable logistic regression model was developed to identify independent predictors of a good outcome. RESULTS: Of 212 participants, 136 (64%) had a good pain outcome and 76 (36%) a poor pain outcome. In multivariable analysis, higher self-efficacy was associated with a significantly higher likelihood of good outcome (adjusted odds ratio [OR] 1.14 [95% confidence interval (95% CI) 1.04-1.24]); higher pain catastrophizing was associated with a significantly lower likelihood of good outcome (adjusted OR 0.88 [95% CI 0.83-0.94]). CONCLUSION: This stage-based measure provides a meaningful and interpretable means to assess pain outcome in knee OA. The odds of a good 2-year outcome in knee OA were lower in persons with greater pain catastrophizing and higher in persons with greater self-efficacy. Targeting these factors may help to improve pain outcome in knee OA.

Significance of preradiographic magnetic resonance imaging lesions in persons at increased risk of knee osteoarthritis.

OBJECTIVE: Little is known about early knee osteoarthritis (OA). The significance of lesions on magnetic resonance imaging (MRI) in older persons without radiographic OA is unclear. Our objectives were to determine the extent of tissue pathology by MRI and evaluate its significance by testing the following hypotheses: cartilage damage, bone marrow lesions, and meniscal damage are associated with prevalent frequent knee symptoms and incident persistent symptoms; bone marrow lesions and meniscal damage are associated with incident tibiofemoral (TF) cartilage damage; and bone marrow lesions are associated with incident patellofemoral (PF) cartilage damage. METHODS: In a cohort study of 849 Osteoarthritis Initiative (OAI) participants who had a bilateral Kellgren/Lawrence (K/L) score of 0, we assessed cartilage damage, bone marrow lesions, and meniscal damage using the MRI OA Knee Score, as well as prevalent frequent knee symptoms, incident persistent symptoms, and incident cartilage damage. Multiple logistic regression (one knee per person) was used to evaluate associations between MRI lesions and each of these outcomes. RESULTS: Of the participants evaluated, 76% had cartilage damage, 61% had bone marrow lesions, 21% had meniscal tears, and 14% had meniscal extrusion. Cartilage damage (any; TF and PF), bone marrow lesions (any; TF and PF), meniscal extrusion, and body mass index (BMI) were associated with prevalent frequent symptoms. Cartilage damage (isolated PF; TF and PF), bone marrow lesions (any; isolated PF; TF and PF), meniscal tears, and BMI were associated with incident persistent symptoms. Hand OA, but no individual lesion type, was associated with incident TF cartilage damage, and bone marrow lesions (any; any PF) with incident PF damage. Having more lesion types was associated with a greater risk of outcomes. CONCLUSION: MRI-detected lesions are not incidental and may represent early disease in persons at increased risk of knee OA.

Comparison of discharge functional status after rehabilitation in skilled nursing, home health, and medical rehabilitation settings for patients after hip fracture repair.

OBJECTIVE: To examine differences in rehabilitation outcomes across 3 post-acute care (PAC) rehabilitation settings for patients after hip fracture repair. DESIGN: Prospective, observational cohort study. SETTING: Six skilled nursing facilities (SNFs), 4 inpatient rehabilitation facilities (IRFs), and 8 home health agencies (HHAs) in 10 states. PARTICIPANTS: Patients (N=181) receiving PAC rehabilitation following hip fracture with internal fixation (n=116) or total hip replacement (n=64), or no surgical intervention (n=1). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Self-care and mobility status at PAC discharge measured by the Inpatient Rehabilitation Facility Patient Assessment Instrument. RESULTS: IRF and HHA patients had lower self-care function at discharge relative to SNF patients controlling for patient characteristics, severity, comorbidities, and services. Adding length of stay (LOS) resulted in nonsignificant differences between IRFs and SNFs. In contrast, there was no setting-specific advantage in discharge mobility for patients with or without the addition of LOS. The average LOS of HHA patients was 2 weeks longer than that of SNF patients, whose average LOS was 9 days longer than that of IRF patients (average, 15d). IRF and SNF patients received about the same total minutes of therapy over their PAC stays (∼2100min on average), whereas HHA patients received only approximately 25% as many minutes. CONCLUSIONS: Setting-specific effects varied depending on whether self-care or mobility was the outcome of focus. It remains unclear to what extent rehabilitation intensity or natural recovery effects changes in functional status for patients with hip fracture. This study points to important directions for PAC setting comparative effectiveness studies in the future, including uniform measurement, limited consensus on factors affecting recovery, accounting for selection bias, and using end-point data collection that is at the same follow-up time periods for all settings.

The role of varus and valgus alignment in the initial development of knee cartilage damage by MRI: the MOST study.

OBJECTIVE: Varus and valgus alignment are associated with progression of knee osteoarthritis, but their role in incident disease is less certain. Radiographic measures of incident knee osteoarthritis may be capturing early progression rather than disease development. The authors tested the hypothesis: in knees with normal cartilage morphology by MRI, varus is associated with incident medial cartilage damage and valgus with incident lateral damage. METHODS: In MOST, a prospective study of persons at risk of or with knee osteoarthritis, baseline full-limb x-rays and baseline and 30-month MRI were acquired. In knees with normal baseline cartilage morphology in all tibiofemoral subregions, logistic regression was used with generalised estimating equations to examine the association between alignment and incident cartilage damage adjusting for age, gender, body mass index, laxity, meniscal tear and extrusion. RESULTS: Of 1881 knees, 293 from 256 persons met the criteria. Varus versus non-varus was associated with incident medial damage (adjusted OR 3.59, 95% CI 1.59 to 8.10), as was varus versus neutral, with evidence of a dose effect (adjusted OR 1.38/1° varus, 95% CI 1.19 to 1.59). The findings held even excluding knees with medial meniscal damage. Valgus was not associated with incident lateral damage. Varus and valgus were associated with a reduced risk of incident lateral and medial damage, respectively. CONCLUSION: In knees with normal cartilage morphology, varus was associated with incident cartilage damage in the medial compartment, and varus and valgus with a reduced risk of incident damage in the less loaded compartment. These results support that varus increases the risk of the initial development of knee osteoarthritis.

Excess body weight and four-year function outcomes: comparison of African Americans and whites in a prospective study of osteoarthritis.

OBJECTIVE: We evaluated whether African Americans in the Osteoarthritis Initiative (OAI) have a greater risk (versus whites) of poor 4-year function outcome within strata defined by sex, body mass index (BMI), and waist circumference. METHODS: Using Western Ontario and McMaster Universities Osteoarthritis Index function, 20-meter walk, and chair stand performance, poor outcome was defined as moving into a worse function group or remaining in the 2 worst groups over 4 years. Logistic regression was used to evaluate the relationship between racial group and outcome within each stratum, adjusting for age, education, and income, and then further adjusting for BMI, comorbidity, depressive symptoms, physical activity, knee pain, and osteoarthritis (OA) severity. RESULTS: In 3,695 persons with or at higher risk for knee OA, higher BMI and large waist circumference were each associated with poor outcome. Among women with high BMI and among women with large waist circumference, African Americans were at greater risk for poor outcome by every measure, adjusting for age, education, and income. From fully adjusted models, potential explanatory factors included income, comorbidity, depressive symptoms, pain, and disease severity. Findings were less consistent for men, emerging only for the 20-meter walk or chair stand outcomes, and potentially explained by age and knee pain. CONCLUSION: Among OAI women with excess body weight, African Americans are at greater risk than whites for poor 4-year outcome. Modifiable factors that may help to explain these findings in the OAI include comorbidity, depressive symptoms, and knee pain. Targeting such factors, while supporting weight loss, may help to lessen the outcome disparity between African American and white women.

A comparison of discharge functional status after rehabilitation in skilled nursing, home health, and medical rehabilitation settings for patients after lower-extremity joint replacement surgery.

OBJECTIVE: To examine differences in outcomes of patients after lower-extremity joint replacement across 3 post-acute care (PAC) rehabilitation settings. DESIGN: Prospective observational cohort study. SETTING: Skilled nursing facilities (SNFs; n=5), inpatient rehabilitation facilities (IRFs; n=4), and home health agencies (HHAs; n=6) from 11 states. PARTICIPANTS: Patients with total knee (n=146) or total hip replacement (n=84) not related to traumatic injury. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Self-care and mobility status at PAC discharge measured by using the Inpatient Rehabilitation Facility Patient Assessment Instrument. RESULTS: Based on our study sample, HHA patients were significantly less dependent than SNF and IRF patients at admission and discharge in self-care and mobility. IRF and SNF patients had similar mobility levels at admission and discharge and similar self-care at admission, but SNF patients were more independent in self-care at discharge. After controlling for differences in patient severity and length of stay in multivariate analyses, HHA setting was not a significant predictor of self-care discharge status, suggesting that HHA patients were less medically complex than SNF and IRF patients. IRF patients were more dependent in discharge self-care even after controlling for severity. For the full discharge mobility regression model, urinary incontinence was the only significant covariate. CONCLUSIONS: For the patients in our U.S.-based study, direct discharge to home with home care was the optimal strategy for patients after total joint replacement surgery who were healthy and had social support. For sicker patients, availability of 24-hour medical and nursing care may be needed, but intensive therapy services did not seem to provide additional improvement in functional recovery in these patients.

Varus-valgus alignment: reduced risk of subsequent cartilage loss in the less loaded compartment.

OBJECTIVE: Varus-valgus alignment has been linked to subsequent progression of osteoarthritis (OA) within the mechanically stressed (medial for varus, lateral for valgus) tibiofemoral compartment. Cartilage data from the off-loaded compartment are sparse. The purpose of this study was to examine our hypotheses that neutral and valgus (versus varus) knees each have reduced odds of cartilage loss in the medial subregions and that neutral and varus (versus valgus) knees each have reduced odds of cartilage loss in the lateral subregions. METHODS: Patients with knee OA underwent knee magnetic resonance imaging at baseline and 2 years. The mean cartilage thickness was quantified within 5 tibial and 3 femoral subregions. We used logistic regression with generalized estimating equations to analyze the relationship between baseline alignment and subregional cartilage loss at 2 years, adjusting for age, sex, body mass index, and disease severity. RESULTS: A reduced risk of cartilage loss in the medial subregions was associated with neutral (versus varus) alignment (external tibial, central femoral, external femoral) and with valgus (versus varus) alignment (central tibial, external tibial, central femoral, external femoral). A reduced risk of cartilage loss in the lateral subregions was associated with neutral (versus valgus) alignment (central tibial, internal tibial, posterior tibial) and with varus (versus valgus) alignment (central tibial, external tibial, posterior tibial, external femoral). CONCLUSION: Neutral and valgus alignment were each associated with a reduction in the risk of subsequent cartilage loss in certain medial subregions and neutral and varus alignment with a reduction in the risk of cartilage loss in certain lateral subregions. These results support load redistribution as an in vivo mechanism of the long-term alignment effects on cartilage loss in knee OA.