BACKGROUND-Magnetic resonance imaging (MRI) of the knee is often performed in patients who have knee symptoms of unclear cause. When meniscal tears are found, it is commonly assumed that the symptoms are attributable to them. However, there is a paucity of data regarding the prevalence of meniscal damage in the general population and the association of meniscal tears with knee symptoms and with radiographic evidence of osteoarthritis.

Objective. Knee osteoarthritis (OA) is highly prevalent, especially in the elderly. Preventive strategies require a knowledge of risk factors that precede disease onset. The present study was conducted to determine the longitudinal risk factors for knee OA in an elderly population.Methods. A longitudinal study of knee OA involving members of the Framingham Study cohort was performed. Weight-bearing knee radiographs were obtained in 1983-1985 (baseline) index increased the risk of OA (OR = 1.6 per 5-unit increase, 95% CI 1.2-2.2), and weight change was directly correlated with the risk of OA (OR = 1.4 per 10-lb change in weight, 95% CI 1.1-1.8). Physical activity increased the risk of OA (for those in the highest quartile, OR = 3.3, 95% CI 1.4-7.5). Smokers had a lower risk than did nonsmokers (for those who smoked an average of 1 1 0 cigarettedday, OR = 0.4, 95% CI 0.2-0.8). Factors not associated with the risk of OA included chondrocalcinosis and a history of hand OA. Weight-related factors affected the risk of OA only in women.Conclusion. Elderly persons at high risk of developing radiographic knee OA included obese persons, nonsmokers, and those who were physically active. The direction of weight change correlated directly with the risk of developing OA.Osteoarthritis (OA) is the most common joint disease, especially in the elderly. However, partly because of the slow time course of disease development, no substantial longitudinal studies of risk factors for the disease have been performed. Knowledge of the risk factors for knee OA has been derived from crosssectional studies.Similar to many chronic diseases, the pathogenesis of OA is likely to be multifactorial. Risk factors consistently associated with the disease in cross-sectional studies include older age, female sex, and being overweight (1). In cross-sectional studies, the OA could develop first, leading a person to become sedentary and to gain weight. We have reported that higher weight in early life predisposes patients to knee OA (2), and that weight loss lowers the risk of developing symptomatic knee OA (3). Both results were based on a one-time assessment of OA occurrence (3). We (4) and others ( 5 )

Objective. To determine the incidence of radiographic knee osteoarthritis (OA) and symptomatic OA (symptoms plus radiographic OA), as well as the rate of progression of preexisting radiographic OA in a population-based sample of elderly persons.Methods. Framingham Osteoarthritis Study subjects who had knee radiographs and had answered questions about knee symptoms in 1983-1985 were reexamined in 1992-1993 (mean 8. l-year interval) using the same protocol. Subjects were defined as having new (incident) radiographic OA if they developed grade 2 2 OA (at least definite osteophytes or definite joint space narrowing). New symptomatic OA was present if subjects developed a combination of knee symptoms and grade 2 2 OA. Progressive OA was diagnosed when radiographs showing grade 2 disease at baseline showed grade 2 3 disease on followup.Results. progressive disease occurred slightly more often in women (relative risk = 1.4; 95% CI 0.8-2.5) but rates did not vary by age in this sample. Among women, approximately 2 % per year developed incident radiographic disease, 1 % per year developed symptomatic knee OA, and about 4% per year experienced progressive knee OA.Conchsion. In elderly persons, the new onset of knee OA is frequent and is more common in women than men. However, among the elderly, age may not affect new disease occurrence or progression.Symptomatic knee osteoarthritis (OA) affects -6% of the adult population and occurs in almost 10% of those over age 65 (1). It accounts for the majority of total knee replacements in the United States, and recent evidence suggests that it accounts for as much lower extremity physical disability in the elderly as any other disease (2). For a disease so common and with such an enormous impact on affected persons and on society, remarkably little is known about its incidence and progression in the population. While the prevalence of knee OA has now been studied, the development of OA over time and the rate of progression of both radiographic and symptomatic disease are poorly characterized. Evaluations of etiologic factors, secular trends in disease, and comparisons of disease rates across populations are best performed with information on the rate of incident or new disease.There has been only one population-based incidence study of knee OA that incorporated serial radiographs of the knees and questions about symptoms. This important 12-year followup study of subjects from Holland (3) evaluated only 258 subjects and found low incidence rates.Studies of disease progression have been more

Osteoarthritis is one of the most common joint disorders in the elderly, yet few studies have targeted symptomatic osteoarthritis, especially symptomatic hand osteoarthritis. The authors conducted a survey in 1992-1993 among an elderly population to estimate the prevalence of symptomatic hand osteoarthritis and to assess its impact on grip strength and functional activities. Framingham Study subjects received hand radiographs and answered queries on joint symptoms. Functional activities were assessed using an interviewer-administered questionnaire. Grip strength and observed functional performance were evaluated using standard procedures. A hand joint was defined as having symptomatic osteoarthritis if both symptoms and radiographic evidence of osteoarthritis were present. Of 1,041 subjects aged 71-100 years (36% men), the prevalence of symptomatic hand osteoarthritis was higher in women (26.2%) than in men (13.4%). Compared with those without symptomatic hand osteoarthritis, subjects with the disease had 10% reduced maximal grip strength, reported more difficulty writing, handling, or fingering small objects (odds ratio = 3.4), and showed more self-reported and observed difficulty carrying a 10-pound (4.5-kg) bundle (odds ratio = 1.7 and 1.6, respectively). In conclusion, in the context of a remarkable paucity of data on the epidemiology of symptomatic hand osteoarthritis, this study suggests that symptomatic hand osteoarthritis is a common disease among elders and frequently impairs hand function.

Objectives To describe the prevalence and longitudinal course of radiographic, erosive and symptomatic hand osteoarthritis (HOA) in the general population. Methods Framingham osteoarthritis (OA) study participants obtained bilateral hand radiographs at baseline and 9-year follow-up. The authors defined radiographic HOA at joint level as Kellgren–Lawrence grade (KLG)≥2, erosive HOA as KLG≥2 plus erosion and symptomatic HOA as KLG≥2 plus pain/aching/stiffness. Presence of HOA at individual level was defined as ≥1 affected joint. The prevalence was age-standardised (US 2000 Population 40–84 years). Results Mean (SD) baseline age was 58.9 (9.9) years (56.5% women). The age-standardised prevalence of HOA was only modestly higher in women (44.2%) than men (37.7%), whereas the age-standardised prevalence of erosive and symptomatic OA was much higher in women (9.9% vs 3.3%, and 15.9% vs 8.2%). The crude incidence of HOA over 9-year follow-up was similar in women (34.6%) and men (33.7%), whereas the majority of those women (96.4%) and men (91.4%) with HOA at baseline showed progression during follow-up. Incident metacarpophalangeal and wrist OA were rare, but occurred more frequently and from an earlier age in men than women. Development of erosive disease occurred mainly in those with non-erosive HOA at baseline (as opposed to those without HOA), and was more frequent in women (17.3%) than men (9.6%). Conclusions The usual female predominance of prevalent and incident HOA was less clear for radiographic HOA than for symptomatic and erosive HOA. With an ageing population, the impact of HOA will further increase.

Objective To examine use of magnetic resonance imaging (MRI) of knees with no radiographic evidence of osteoarthritis to determine the prevalence of structural lesions associated with osteoarthritis and their relation to age, sex, and obesity.Design Population based observational study. Setting Community cohort in Framingham, MA, United States (Framingham osteoarthritis study).Participants 710 people aged >50 who had no radiographic evidence of knee osteoarthritis (Kellgren-Lawrence grade 0) and who underwent MRI of the knee. Main outcome measuresPrevalence of MRI findings that are suggestive of knee osteoarthritis (osteophytes, cartilage damage, bone marrow lesions, subchondral cysts, meniscal lesions, synovitis, attrition, and ligamentous lesions) in all participants and after stratification by age, sex, body mass index (BMI), and the presence or absence of knee pain. Pain was assessed by three different questions and also by WOMAC questionnaire. ResultsOf the 710 participants, 393 (55%) were women, 660 (93%) were white, and 206 (29%) had knee pain in the past month. The mean age was 62.3 years and mean BMI was 27.9. Prevalence of "any abnormality" was 89% (631/710) overall. Osteophytes were the most common abnormality among all participants (74%, 524/710), followed by cartilage damage (69%, 492/710) and bone marrow lesions (52%, 371/710). The higher the age, the higher the prevalence of all types of abnormalities detectable by MRI. There were no significant differences in the prevalence of any of the features between BMI groups. The prevalence of at least one type of pathology ("any abnormality") was high in both painful (90-97%, depending on pain definition) and painless (86-88%) knees.Conclusions MRI shows lesions in the tibiofemoral joint in most middle aged and elderly people in whom knee radiographs do not show any features of osteoarthritis, regardless of pain. IntroductionAgeing of the population and increasing obesity contribute to morbidity worldwide. Osteoarthritis is the most prevalent medically treated arthritic condition worldwide (for example, 3532 per 100 000 people in the United States).1 2 Diagnosis of osteoarthritis is made on the basis of clinical examination or radiography. Population based longitudinal studies in the US 3 and the United Kingdom 4 showed the lifetime risk of knee osteoarthritis increases with age, 3 with the risk highest in obese people.3 4 Other prevalence surveys showed that radiographic osteoarthritis of the knee is common in middle aged and older adults. Although many publications have reported structural changes in people with radiographic knee osteoarthritis, few data are available regarding what structural changes are present in knees without any radiographic features of osteoarthritis. About half of people with knee pain have no radiographic osteoarthritis. In clinical practice, it is unclear how to investigate and manage such people and whether additional imaging with magnetic resonance imaging would be of clinical value. Such data can be collected only i...

Objective. Results of cross-sectional studies have suggested that bone marrow lesions (BMLs) visualized on magnetic resonance imaging (MRI) are related to knee pain, but no longitudinal studies have been done. This study was undertaken to determine whether enlarging BMLs are associated with new knee pain.Methods. Subjects ages 50-79 years with knee osteoarthritis (OA) or at high risk of knee OA were asked twice at baseline about the presence of knee pain, aching, or stiffness (classified as frequent knee pain) on most days; absence of knee pain was the baseline eligibility criterion. At 15 months' followup, subjects were again queried twice about frequent knee pain. A case knee was defined as absence of knee pain at baseline but presence of knee pain both times at followup. Controls were selected randomly from among knees with absence of pain at baseline. All MR images were scored for volume of BMLs in the medial, lateral, and patellofemoral compartments. We focused on the maximal change in BML score among the knee compartments from baseline to 15 months. Multiple logistic regression, with adjustments for demographic and clinical variables, was used to assess whether an increased BML score is predictive of the development of knee pain.Results. Among case knees, 54 of 110 (49.1%) showed an increase in BML score within a compartment, whereas only 59 of 220 control knees (26.8%) showed an increase (P < 0.001 by chi-square test). A BML score increase of at least 2 units was much more common in case knees than in control knees (27.5% versus 8.6%; adjusted odds ratio 3.2, 95% confidence interval 1.5-6.8). Among case knees with increased BMLs, most already had BMLs at baseline, with enlarging BMLs at followup, but among the subset of knees with no BMLs at baseline, new BMLs were more common in case knees (11 [32.4%] of 34) than in control knees (9 [10.8%] of 83).Conclusion. Development of knee pain is associated with an increase in BMLs as revealed on MRI.

Objective To examine the relation of radiographic features of osteoarthritis to knee pain in people with knees discordant for knee pain in two cohorts. Design Within person, knee matched, case-control study. Setting and participants Participants in the Multicenter Osteoarthritis (MOST) and Framingham Osteoarthritis studies who had knee radiographs and assessments of knee pain. Main outcome measures Association of each pain measure (frequency, consistency, and severity) with radiographic osteoarthritis, as assessed by Kellgren and Lawrence grade (0-4) and osteophyte and joint space narrowing grades (0-3) among matched sets of two knees within individual participants whose knees were discordant for pain status. Results 696 people from MOST and 336 people from Framingham were included. Kellgren and Lawrence grades were strongly associated with frequent knee pain -for example, for Kellgren and Lawrence grade 4 v grade 0 the odds ratio for pain was 151 (95% confidence interval 43 to 526) in MOST and 73 (16 to 331) in Framingham (both P<0.001 for trend). Similar results were also seen for the relation of Kellgren and Lawrence scores to consistency and severity of knee pain. Joint space narrowing was more strongly associated with each pain measure than were osteophytes. Conclusions Using a method that minimises between person confounding, this study found that radiographic osteoarthritis and individual radiographic features of osteoarthritis were strongly associated with knee pain.