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 measures Prevalence 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.Results Of 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.
Our objective was to identify precise mechanical metrics of the proximal tibia which differentiated OA and normal knees. We developed subject-specific FE models for 14 participants (7 OA, 7 normal) ...who were imaged three times each for assessing precision (repeatability). We assessed various mechanical metrics (minimum principal and von Mises stress and strain as well as structural stiffness) across the proximal tibia for each subject. In vivo precision of these mechanical metrics was assessed using CV%
. We performed parametric and non-parametric statistical analyses and determined Cohen's d effect sizes to explore differences between OA and normal knees. For all FE-based mechanical metrics, average CV%
was less than 6%. Minimum principal stress was, on average, 75% higher in OA versus normal knees while minimum principal strain values did not differ. No difference was observed in structural stiffness. FE modeling could precisely quantify and differentiate mechanical metrics variations in normal and OA knees, in vivo. This study suggests that bone stress patterns may be important for understanding OA pathogenesis at the knee.
Subchondral bone cysts are a widely observed, but poorly understood, feature in patients with knee osteoarthritis (OA). Clinical quantitative computed tomography (QCT) has the potential to ...characterize cysts in vivo but it is unclear which specific cyst parameters (e.g., number, size) are associated with clinical signs of OA, such as disease severity or pain. The objective of this study was to use QCT-based image-processing techniques to characterize subchondral tibial cysts in patients with knee OA and to explore relationships between proximal tibial subchondral cyst parameters and subchondral bone density as well as clinical characteristics of OA (alignment, joint space narrowing (JSN), OA severity, pain) in patients with knee OA.
The preoperative knee of 42 knee arthroplasty patients was scanned using QCT. Patient characteristics were obtained, including OA severity, knee pain, JSN, and alignment. We used 3D image processing techniques to obtain cyst parameters including: cyst number, cyst number per proximal tibial volume, cyst volume per proximal tibial volume, as well as maximum and average cyst volume across the proximal tibia, as well as regional bone mineral density (BMD) excluding cysts. We used Spearman's correlation coefficients to explore associations between patient characteristics and cyst parameters.
At both the medial and lateral compartments of the proximal tibia, greater cyst number and volume were associated with higher BMD. At the lateral region, cyst number and volume were also associated with lateral OA severity, lateral JSN, alignment and sex. Pain was not associated with any cyst parameters at any region.
Cyst number and volume were associated with BMD at both the medial and lateral compartments. Lateral cyst number and volume were also associated with joint alignment, OA severity, JSN and sex. This is the first study to use clinical QCT to explore subchondral tibial cysts in patients with knee OA and provides further evidence of the relationships between subchondral cysts and clinical OA characteristics.
Our objective was to examine the relationships between proximal tibial trabecular (epiphyseal and metaphyseal) bone mineral density (BMD) and osteoarthritis (OA)-related pain in patients with severe ...knee OA.
The knee was scanned preoperatively using quantitative computed tomography (QCT) in 42 patients undergoing knee arthroplasty. OA severity was classified using radiographic Kellgren-Lawrence scoring and pain was measured using the pain subsection of the Western Ontario and McMaster Universities Arthritis Index (WOMAC). We used three-dimensional image processing techniques to assess tibial epiphyseal trabecular BMD between the epiphyseal line and 7.5 mm from the subchondral surface and tibial metaphyseal trabecular BMD 10 mm distal from the epiphyseal line. Regional analysis included the total epiphyseal and metaphyseal region, and the medial and lateral epiphyseal compartments. The association between total WOMAC pain scores and BMD measurements was assessed using hierarchical multiple regression with age, sex, and body mass index (BMI) as covariates. Statistical significance was set at p < 0.05.
Total WOMAC pain was associated with total epiphyseal BMD adjusted for age, sex, and BMI (p = 0.013) and total metaphyseal BMD (p = 0.017). Regionally, total WOMAC pain was associated with medial epiphyseal BMD adjusted for age, sex, and BMI (p = 0.006).
These findings suggest that low proximal tibial trabecular BMD may have a role in OA-related pain pathogenesis.
Context: Although racial and ethnic differences in vitamin D status and bone mineral density (BMD) are recognized, less is known about how differences in vitamin D status impact BMD, especially among ...men.
Objective: Our objective was to examine the relation between serum 25-hydroxyvitamin D 25(OH)D and BMD by race and ethnic group.
Design: We conducted a population-based, observational survey.
Participants: Participants included 1114 Black, Hispanic, and White men, 30–79 yr of age.
Outcomes: We assessed 25(OH)D by a competitive protein binding assay and BMD by dual-energy x-ray absorptiometry.
Results: Mean age ± sd of the 331 Black, 362 Hispanic, and 421 White men was 48 ± 12.8 yr. Mean 25(OH)D was lower among Black (25.0 ± 14.7 ng/ml) and Hispanic (32.9 ± 13.9 ng/ml) men compared with White men (37.4 ± 14.0 ng/ml, P < 0.01). A higher percentage of both Black (44%) and Hispanic (23%) men had levels of 25(OH)D in the lowest quartile, compared with 11% of White men (P < 0.001). After adjusting for age, height, and weight, only White men showed significant positive correlation between 25(OH)D and BMD (range of correlations, 0.00–0.14). Serum 25(OH)D was not associated with BMD in Black or Hispanic men at any bone site. Results were similar when adjusted for age only.
Conclusions: Our findings confirm substantial racial and ethnic group differences in BMD and serum 25(OH)D in men. Serum 25(OH)D and BMD are significantly related to one another in White men only. This may have implications for evaluation of bone health and supplementation in men with low levels of 25(OH)D. Further understanding of the biological mechanisms for these differences between race and ethnic groups is needed.
Objective
To test the in vivo precision of a depth-specific topographic mapping technique (CT-TOMASD, computed tomography topographic mapping of subchondral density) for the 3D assessment of ...subchondral cortical and trabecular bone density in normal and osteoarthritic (OA) human tibiae.
Methods
Fourteen participants were recruited (3 men:11 women; mean age: 49.9, SD: 11.9 years) and categorized as normal (
n
= 7) or OA (
n
= 7). Each participant was scanned using clinical quantitative CT (QCT) three times over 2 days. We assessed average subchondral bone mineral density (BMD) across three layers (0–2.5 mm, 2.5–5 mm and 5–10 mm) measured in relation to depth from the subchondral surface. Regional analyses included: medial plateau BMD; lateral plateau BMD; anterior/central/posterior compartment BMD; medial:lateral (M:L) BMD ratio; and average BMD of a 10-mm diameter “focal spot,” which searched each medial and lateral plateau for the highest focal densities present within each plateau. Precision was assessed using root mean square coefficients of variation (CV%
RMS
) and intraclass correlation coefficients (ICC).
Results
Average CV%
RMS
precision errors for BMD measures were 2.3%, reaching a maximum CV%
RMS
of 3.9%. ICC showed high repeatability above 0.98.
Conclusions
CT-TOMASD offered precise 3D measures of subchondral BMD. This method has the potential to identify and quantify changes in subchondral BMD associated with OA in vivo.
There are lingering questions regarding the relation between alcohol consumption and breast cancer risk in women. The authors performed a meta-analysis of epidemiologic studies carried out through ...1999 to examine the dose-response relation and to assess whether effect estimates differed according to various study characteristics. Overall, there was a monotonic increase in the relative risk of breast cancer with alcohol consumption, but the magnitude of the effect was small; in comparison with nondrinkers, women averaging 12 g/day of alcohol consumption (approximately one typical drink) had a relative risk of 1.10 (95% confidence interval (CI): 1.06, 1.14). Estimates of relative risk were 7% greater in hospital-based case-control studies than in cohort studies or community-based case-control studies, 3% greater in studies published before 1990 than in studies published later, and 5% greater in studies conducted outside of the United States than in US studies. The findings of five US cohort studies published since 1990 yielded a relative risk of 1.06 (95% CI: 1.00, 1.11) for consumers of 12 g/day, as compared with nondrinkers. Cohort studies with less than 10 years of follow-up gave estimates 11% higher than cohort studies with longer follow-up periods. No meaningful difference was seen by menopausal status or type of beverage consumed.
It has been suggested that a high-fat meal may acutely impair endothelium-dependent vasodilation and that this impairment may be prevented by concomitant intake of antioxidants. Because red wine ...contains antioxidant polyphenols and may reduce cardiovascular disease, we examined the effect of red wine on postprandial endothelial function. Using a crossover design, 13 healthy volunteers consumed a high-fat meal (0.8 g fat/kg body weight) with red wine (3 ml/kg) or an isocaloric control beverage on 2 separate days, 1 week apart. Flow-mediated dilation of the brachial artery was examined by vascular ultrasound at baseline and at 2, 4, and 6 hours after the meal. At these times, flow-mediated dilation with the high-fat meal and control beverage was 9.5 ± 5.0%, 7.9 ± 5.1%, 6.8 ± 3.6%, and 7.3 ± 4.6%, respectively (nonsignificant trend). There was also a nonsignificant trend for flow-mediated dilation after the high-fat meal with wine: 8.0 ± 4.1%, 5.7 ± 4.7%, 6.4 ± 3.1%, and 6.9 ± 3.8%, respectively. There was no difference in the effects between wine and the control beverage (p = 0.77). Triglycerides increased 2- to 2.7-fold over baseline (p = 0.0001) with a peak occurring 5 hours after the high-fat meals. In contrast to previous studies, the present study did not demonstrate a significant effect of a high-fat meal on endothelial vasomotor function in healthy subjects. Under these conditions, we did not demonstrate a beneficial acute effect of red wine on endothelial function.
Summary Objectives Bone attrition probably constitutes remodeling of the bone, resulting in flattening or depression of the articular surfaces. Defining bone attrition is challenging because it is an ...accentuation of the normal curvature of the tibial plateaus. We aimed to define bone attrition on magnetic resonance imaging (MRI) of the knee using information from both radiographs and MRIs, and to assess whether bone attrition is common prior to end stage disease osteoarthritis (OA) in the tibio-femoral joint. Methods All knees of participants in the community-based sample of the Framingham OA Study were evaluated for bone attrition in radiographs and MRIs. Radiographs were scored based on templates designed to outline the normal contours of the tibio-femoral joint. MRIs were analyzed using the semi-quantitative Whole-Organ Magnetic Resonance Imaging Scoring (WORMS) method. The prevalence of bone attrition was calculated using two different thresholds for MRI scores. Results Inter-observer agreement for identification of bone attrition was substantial for the radiographs ( κ = 0.71, 95% CI 0.67–0.81) and moderate for MRI ( κ = 0.56, 95% CI 0.40–0.72). Of 964 knees, 5.7% of the radiographs showed bone attrition. Of these, 91% of MRIs were also read as showing bone attrition. We selected a conservative threshold for bone attrition on MRI scoring (≥2 on a 0–3 scale) based on agreement with attrition on the radiograph or when bone attrition on MRI co-occurred with cartilage loss on OA. Using this threshold for bone attrition on MRI, bone attrition was common in knees with OA. For example, in knees with mild OA but no joint space narrowing, 13 of 88 MRIs (14.8%) showed bone attrition. Conclusions Using MRI we found that many knees with mild OA without joint narrowing on radiographs had bone attrition, even using conservative definitions. The validity of our definition of bone attrition should be evaluated in further studies. Bone attrition may occur in milder OA and at earlier stages of disease than previously thought.
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