Related Articles

The purpose of this study was to estimate the prevalence of radiographic and symptomatic knee osteoarthritis (OA) among community residents and to elucidate the relevant risk factors. This prospective, population-based study was conducted on residents over 50 yr of age in Chuncheon. Subjects completed an interview based on a standardized questionnaire and clinical evaluation including standardized weight bearing semiflexed knee A-P radiographs. We defined a subject with the Kellgren and Lawrence grade ≥2 as having radiographic knee OA (ROA). Symptomatic knee OA (SOA) was defined by the presence of both ROA and knee pain. We obtained symptom information and radiographs from 504 subjects. The prevalence of ROA and SOA was 37.3% and 24.2%, respectively. The prevalence of both ROA and SOA was significantly higher among women than among men. Multivariate analysis revealed that the presence of hypertension, and a manual occupation were significantly associated with the presence of ROA and SOA. Lower level of education was significantly associated with the presence of ROA, and female sex with the presence of SOA. In conclusion, both ROA and SOA are common in the aged adult population of Korea, with preponderance for women.

Objective

To define and contrast multiple joint radiographic osteoarthritis (rOA) phenotypes describing hand and whole-body rOA among African Americans and Caucasians.

Methods

We conducted a cross-sectional analysis in the Johnston County Osteoarthritis Project, using radiographic data for the hands, tibiofemoral (TFJ) and patellofemoral joints, hips, and lumbosacral spine (LS). Films were read for rOA by a single radiologist using standard atlases. Sixteen mutually exclusive hand (n=2083) and 32 whole-body rOA phenotypes (n=1419) were identified. Fisher’s exact tests, corrected for multiple comparisons, were used to compare phenotype frequencies by race and gender. Logistic regression was used to provide odds ratios adjusted for gender, age, and body mass index (BMI).

Results

Hand rOA phenotypes: African Americans compared with Caucasians had significantly less frequent rOA of the distal interphalangeal joints, in isolation and in combination with other hand joint sites, but comparable frequencies of rOA for other hand joint sites. Whole-body rOA phenotypes: African Americans compared with Caucasians had less frequent Hand rOA, in isolation and in combination with other joint sites. In contrast, African Americans compared with Caucasians had more than twice the odds of isolated TFJ rOA and 77% higher odds of TFJ and LS rOA together.

Conclusions

Even after adjustment for gender, age, and BMI, African Americans compared to Caucasians were less likely to have hand rOA phenotypes, but more likely to have knee rOA phenotypes involving the TFJ. African Americans may have a higher burden of multiple large joint OA involvement not captured by most definitions of “generalized OA.”

Objective

To assess the relation between the urinary concentrations of type II collagen C‐telopeptide (UCTX‐II) and radiographic signs of osteoarthritis (ROA) in the GARP (Genetics, Arthrosis and Progression) study.

Methods

UCTX‐II levels were measured in GARP study participants, who are sibling pairs predominantly with symptomatic osteoarthritis at multiple sites. Kellgren and Lawrence scores were used to assess ROA in the knees, hips, hands, and vertebral facet joints, and spinal disc degeneration. A proportionate score was made for each joint location, based on the number of joints with ROA. The sum total ROA score represents a measure of cartilage abnormalities within each patient. By using linear mixed models the total ROA score and the joint site specific ROA scores were correlated with the UCTX‐II level.

Results

In 302 subjects the mean (SD) and median (range) for UCTX‐II were 265 (168) and 219 (1346) ng/mmol creatine, respectively. There was a significant association between the total ROA score and UCTX‐II levels. Subsequent multivariate analysis showed that the joint site specific ROA score at all joint sites, except for spinal disc degeneration, contributed independently to this association.

Conclusions

The total ROA score of GARP patients, representing cartilage abnormalities at the most prevalent ROA joint locations, showed an excellent correlation with UCTX‐II levels. The specific ROA scores at the hip, hand, facet, and knee joints additively and independently explained this association. Even in patients with osteoarthritis at multiple sites, UCTX‐II may be a sensitive quantitative marker of ROA.

Background

A recent study of adults aged ≥50 years reporting knee pain found an excess of radiographic knee osteoarthritis (knee ROA) in symptomatic males compared to females. This was independent of age, BMI and other clinical signs and symptoms. Since this finding contradicts many previous studies, our objective was to explore four possible explanations for this gender difference: X-ray views, selection, occupation and non-articular conditions.

Methods

A community-based prospective study. 819 adults aged ≥50 years reporting knee pain in the previous 12 months were recruited by postal questionnaires to a research clinic involving plain radiography (weight-bearing posteroanterior semiflexed, supine skyline and lateral views), clinical interview and physical examination. Any knee ROA, ROA severity, tibiofemoral joint osteoarthritis (TJOA) and patellofemoral joint osteoarthritis (PJOA) were defined using all three radiographic views. Occupational class was derived from current or last job title. Proportions of each gender with symptomatic knee ROA were expressed as percentages, stratified by age; differences between genders were expressed as percentage differences with 95% confidence intervals.

Results

745 symptomatic participants were eligible and had complete X-ray data. Males had a higher occurrence (77%) of any knee ROA than females (61%). In 50–64 year olds, the excess in men was mild knee OA (particularly PJOA); in ≥65 year olds, the excess was both mild and moderate/severe knee OA (particularly combined TJOA/PJOA). This male excess persisted when using the posteroanterior view only (64% vs. 52%). The lowest level of participation in the clinic was symptomatic females aged 65+. Within each occupational class there were more males with symptomatic knee ROA than females. In those aged 50–64 years, non-articular conditions were equally common in both genders although, in those aged 65+, they occurred more frequently in symptomatic females (41%) than males (31%).

Conclusion

The excess of knee ROA among symptomatic males in this study seems unlikely to be attributable to the use of comprehensive X-ray views. Although prior occupational exposures and the presence of non-articular conditions cannot be fully excluded, selective non-participation bias seems the most likely explanation. This has implications for future study design.

Objective:

To examine associations between disability and socioeconomic status (SES) in persons with hip radiographic OA (rOA) or symptomatic OA (sxOA) in the Johnston County Osteoarthritis Project.

Methods:

Cross-sectional analyses were conducted on individuals with hip rOA (708) or sxOA (251). rOA was defined as Kellgren-Lawrence ≥ 2. Educational attainment (<12 years or ≥12 years) and occupation (managerial or non-managerial) were individual SES measures. Census block group poverty rate (<12%, 12-25%, ≥25%) was the community SES measure. Disability was measured by the HAQ-DI and the WOMAC (function, pain, total). Covariates included age, gender, race, BMI, and presence of knee symptoms. Analyses examined associations of disability with each SES effect separately, followed by multivariable analyses using all SES variables, adjusting for covariates.

Results:

In models with single SES variables adjusted for covariates, WOMAC scores were associated significantly (p<0.05) with low educational attainment and non-managerial occupation in rOA and sxOA. HAQ was significantly associated with low educational attainment in rOA and sxOA and with high community poverty in rOA. In models including all SES variables, the patterns of association were similar although with diminished significance. There was indication that education was more strongly associated with HAQ and WOMAC function, while occupation was more strongly associated with WOMAC pain.

Conclusion:

Our data provide evidence that individual SES is an important factor to consider when examining disability and pain outcomes in older adults with hip OA.

Objective: To examine the role of an IGF-I gene promoter polymorphism in the prevalence of radiographic osteoarthritis (ROA), and study its interaction with the COL2A1 gene.

Methods: Individuals genotyped for IGF-I (n = 1546) and COL2A1 gene polymorphisms (n = 808) were selected from a random sample (n = 1583) derived from the Rotterdam study. The presence of ROA was defined as a Kellgren score of 2 or more in at least one of four joints (knee, hip, hand, and spine). Genotype specific odds ratios (OR) were adjusted for age, sex, body mass index, and bone mineral density using logistic regression. Interaction with the COL2A1 genotype was tested.

Results: Overall, no association was found between the IGF-I polymorphism and ROA. In subjects aged 65 years or younger (n = 971), the prevalence of ROA increased with the absence of the 192 base pair (bp) allele (p for trend = 0.03). Compared with homozygotes for the 192 bp allele, the prevalence of ROA was 1.4 times higher in heterozygotes (95% confidence interval, 1.0 to 1.8) and 1.9 times higher in non-carriers (1.1 to 3.3). There was evidence of interaction between the IGF-I and COL2A1 genes. Individuals with the risk genotype of both genes had an increased prevalence of ROA (OR 3.4 (1.1 to 10.7)). No effect was observed in subjects older than 65 years.

Conclusions: Subjects with genetically determined low IGF-I expression (non-carriers of the 192 bp allele) may be at increased risk of ROA before the age of 65 years. Furthermore, an interaction between the IGF-I and COL2A1 genes is suggested.

OBJECTIVE—A genetic association study was performed to investigate whether radiographical osteoarthritis (ROA) was associated with specific genotypes of the insulin-like growth factor I (IGF-1) gene.
METHODS—Subjects aged 55-65 years were selected from a population-based study of which ROA at the knee, hip, spine, and hand was assessed. Genotypes were determined of a polymorphism in the promoter region of the IGF-1 gene.
RESULTS—The IGF-1 locus was significantly associated with the presence of ROA (overall adjusted OR for heterozygous subjects = 1.9, 95% CI 1.2, 3.1 and for homozygous subjects 3.6, 95% CI 0.8, 16.2).
CONCLUSION—These results suggest that variation at the IGF-1 locus is associated with ROA development and may play a part in ROA pathogenesis. To confirm these findings replication in another population-based sample is needed.

 Keywords: osteoarthritis; genetics; IGF-1

Objective

Development of functional limitation is thought to be unrelated to changes in severity of radiographic knee osteoarthritis (ROA). We evaluated the relation of change in ROA to the incidence of severe functional limitation.

Methods

Participants of the Multicenter Osteoarthritis (MOST) Study, a cohort study of persons with or at high risk of knee OA were evaluated at 0 and 30 months. Subjects were classified as having no, incident, stable, or worsening ROA. Incidence of severe functional limitation was defined as 1) WOMAC physical function scores (≥ 36/68) and 2) walking speed (≤ 1.0 m/s) at 30 months. The relation of change in ROA to the incidence of severe functional limitation was evaluated by calculating risk ratios adjusted for potential confounders.

Results

Of the 2110 subjects included (mean age 62, mean BMI 30 kg/m2, female 60%), 53% had no, 6% incident, 14% stable, and 27% worsening ROA. Persons with incident ROA had 1.9 and 1.8 times the risk by WOMAC physical function and walking speed, respectively, to have incident severe functional limitation compared with those with no ROA over 30 months. Compared with those with stable ROA, persons with worsening ROA had 2.2 and 2.5 times the risk of incident severe functional limitation, respectively.

Conclusion

Changes in structural disease are associated with the development of severe functional limitations in persons with or even those at high risk of knee OA.

Objective

To study the longitudinal rate of (and sensitivity to) change of knee cartilage thickness across defined stages of radiographic osteoarthritis (ROA), specifically healthy knees and knees with end-stage ROA.

Methods

One knee of 831 Osteoarthritis Initiative (OAI) participants was examined: 112 healthy, without ROA or risk factors for knee OA, and 719 ROA knees: 310 calculated Kellgren Lawrence [cKLG] grade 2, 300 cKLG3, and 109 cKLG4. Subregional change in thickness was assessed after segmentation of weight-bearing femorotibial cartilage at baseline and at one year from coronal MRI. Regional and ordered values (OV) of change were compared by baseline ROA status.

Results

Healthy knees displayed small changes in plates and subregions (±0.7%; standardized response mean [SRM] ±0.15), with OVs being symmetrically distributed around zero. In cKLG2 knees, changes in cartilage thickness were small (≤1%; minimal SRM -0.22) and not significantly different from healthy knees. Knees with cKLG3 showed substantial loss of cartilage thickness (up to -2.5%; minimal SRM -0.35), with OV changes being significantly (p<0.05) greater than those in healthy knees. cKLG4 knees displayed the largest rate of loss across ROA grades (up to -3.9%; minimal SRM -0.51), with OV changes also significantly (p<0.05) greater than in healthy knees.

Conclusion

MRI-based cartilage thickness showed high rates of loss in knees with moderate and end-stage ROA, and small rates (indistinguishable from healthy knees) in mild ROA. From the perspective of sensitivity to change, end-stage ROA knees need not be excluded from longitudinal studies using MRI cartilage morphology as an endpoint.

Introduction

The purpose of this study was to examine data from the Johnston County Osteoarthritis (OA) Project for independent associations of educational attainment, occupation and community poverty with tibiofemoral knee OA.

Methods

A cross-sectional analysis was conducted on 3,591 individuals (66% Caucasian and 34% African American). Educational attainment (< 12 years or ≥12 years), occupation (non-managerial or not), and Census block group household poverty rate (< 12%, 12 to 25%, > 25%) were examined separately and together in logistic models adjusting for covariates of age, gender, race, body mass index (BMI), smoking, knee injury and occupational activity score. Outcomes were presence of radiographic knee OA (rOA), symptomatic knee OA (sxOA), bilateral rOA and bilateral sxOA.

Results

When all three socioeconomic status (SES) variables were analyzed simultaneously, low educational attainment was significantly associated with rOA (odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.20, 1.73), bilateral rOA (OR = 1.43, 95% CI 1.13, 1.81), and sxOA (OR = 1.66, 95% CI 1.34, 2.06), after adjusting for covariates. Independently, living in a community of high household poverty rate was associated with rOA (OR = 1.83, 95% CI 1.43, 2.36), bilateral rOA (OR = 1.56, 95% CI 1.12, 2.16), and sxOA (OR = 1.36, 95% CI 1.00, 1.83). Occupation had no significant independent association beyond educational attainment and community poverty.

Conclusions

Both educational attainment and community SES were independently associated with knee OA after adjusting for primary risk factors for knee OA.

PURPOSE

To assess associations between serum TGF-β1 and radiographic knee and hip osteoarthritis (rOA) in African American (AA) and White men and women.

METHODS

Baseline data from 330 participants in the Johnston County Osteoarthritis Project were used in the analysis. Radiographs were scored with the Kellgren-Lawrence scale and rOA defined as grade ≥ 2. Individual radiographic features (IRFs) were rated 0–3. TGF-β1 was measured using a sandwich ELISA. General linear models were used to estimate associations between lnTGF-β1 and rOA presence, laterality or severity, and IRF presence and severity, adjusting for age, gender, race, and body mass index. Interactions by race and gender were considered significant at p < 0.1.

RESULTS

Mean lnTGF-β1 levels were higher among AAs compared to Whites, and among women compared to men (p<0.009). Mean lnTGF-β1 levels were higher in those with knee OST, but this association was not significant after adjustment. There were no other significant differences in mean lnTGF-β1 levels by presence, laterality, or severity of knee or hip rOA or IRFs. No race or gender interactions were identified, although a borderline significant association between lnTGF-β1 and knee OST was seen among AAs (p < 0.06).

CONCLUSIONS

Although serum TGF-β1 varied by race and gender and several rOA variables, there were no independent significant associations with presence, laterality, or severity of knee or hip rOA by K-L grade or IRFs, suggesting that serum TGF-β1 is unlikely to be useful as a stand-alone biomarker in OA studies. A possible association between TGF-β1 and OST in AAs cannot be excluded.

Introduction

The associations between leptin, interleukin (IL)-6, and hip radiographic osteoarthritis (OA) have not been reported, and their roles in obesity-related hip OA are unclear. The aim of this study was to describe the associations between leptin, IL-6, and hip radiographic osteoarthritis (ROA) in older adults.

Methods

A cross-sectional sample of 193 randomly selected subjects (mean age, 63 years; range, 52 to 78 years; 48% female subjects) were studied. Hip ROA, including joint-space narrowing (JSN) and osteophytes, was determined by anteroposterior radiograph. Serum levels of leptin and interleukin (IL)-6 were measured with radioimmunoassay. Fat mass was measured with dual-energy x-ray absorptiometry (DXA). Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated.

Results

In multivariable analysis, hip JSN was associated with serum levels of leptin in the whole sample (β = 0.046 per μg/L, P = 0.024 for superior; β = 0.068 per μg/L, P = 0.004 for axial compartment) and IL-6 only in females (β = 0.241 per pg/ml, P = 0.002 for superior; β = 0.239 per pg/ml, P = 0.001 for axial compartment). The positive associations between body-composition measures (BMI, WHR, percentage total fat mass, and percentage trunk fat mass) and hip JSN in women became nonsignificant after adjustment for leptin but not for IL-6. No significant associations were found between leptin, IL-6, and the presence or severity of osteophytes.

Conclusions

This study suggests that metabolic and inflammatory mechanisms may play a role in the etiology of hip OA and that the associations between body composition and hip JSN are mediated by leptin, particularly in women.

Objective

To determine if knee alignment measures differ between African Americans and Caucasians without radiographic knee osteoarthritis (rOA).

Methods

A single knee was randomly selected from 175 participants in the Johnston County Osteoarthritis Project without rOA in either knee. Anatomic axis, condylar, tibial plateau, and condylar plateau angles were measured by one radiologist; means were compared and adjusted for age and body mass index (BMI).

Results

There were no significant differences in knee alignment measurements between Caucasians and AfrAm among men or women.

Conclusions

Observed differences in knee rOA occurrence between AfrAm and Caucasians are not explained by differences in static knee alignment.

Objectives

To quantify rates of change in quadriceps muscle (QM) and intermuscular fat (IMF) volumes over 2-years in women in the Osteoarthritis Initiative (OAI) study and examine group differences between those with radiographic OA (ROA) and those without (non-ROA).

Methods

The OAI database was queried for women ≥50 years old in the incident and progression cohorts with and without ROA at baseline. Mid-thigh MRI scans (15 contiguous slices, 5 mm slice thickness) of eligible women were randomly selected and anonymized. Image pairs were registered. QM and IMF were segmented in the 12 most proximal matching slices with the segmenter blinded to image time point. Age-adjusted differences in QM and IMF volume changes between groups were tested using ANCOVA.

Results

41 women without ROA (mean (SD) age 60.7 (7.6) yrs) and 45 with ROA (mean (SD) age 64.5 (6.7) yrs) were included. Mean QM and IMF volume changes in the non-ROA group were -4.1 (11.1) cm3 and 3.4 (7.1) cm3, respectively, and -5.4 (13.5) cm3 and 3.1 (7.4) cm3 in the ROA group, respectively. Age-adjusted between-group differences in QM and IMF changes were not significant (p>0.05).

Conclusions

Two-year changes in QM and IMF volume appear consistent with ageing and do not seem to be related to OA status. Direct comparison with a control cohort without OA risk factors could confirm this. Since group assignment was based on baseline data, there may have been women in the non-ROA group who developed radiographic OA over follow-up resulting in some overlap between groups.

Objective: To compare subjects who had at least one parent with a total knee replacement for severe primary knee osteoarthritis with age and sex matched controls who had no family history of knee osteoarthritis

Design: Population based case–control study of 188 matched pairs (mean age 45 years, range 26 to 60).

Methods: Articular cartilage volume and bone size were determined at the patella and at the medial tibial and lateral tibial compartments by processing images acquired using T1 weighted, fat saturated magnetic resonance imaging. Radiographic osteoarthritis (ROA) was assessed from a standing semiflexed radiograph scored for joint space narrowing and osteophytosis. Knee pain was assessed by questionnaire. Height, weight, body mass index (BMI), lower limb muscle strength, and endurance fitness were measured by standard protocols.

Results: Compared with the controls, index offspring had higher BMI (27.8 v 26.0 kg/m2, p = 0.02), weaker lower limb muscles (127 v 135 kg, p = 0.006), more knee pain (47% v 22%, p<0.001), and greater medial tibial bone area (17.6 v 17.1 cm2, p = 0.01). With the exception of BMI, these differences persisted in multivariate analysis. There was a non-significant trend to higher cartilage volume at tibial sites and increased ROA in the offspring in the total and subgroup analyses, but no difference in height and endurance fitness.

Conclusions: BMI, muscle strength, knee pain, and medial tibial bone area, but not cartilage volume, appear to play a role in the genetic regulation and development of knee osteoarthritis.

Objective

To investigate the relationship between body mass index (BMI) and the incidence and progression of radiological knee as well as of radiological hip osteoarthritis.

Design

Cohort study.

Setting

Population based.

Participants

3585 people aged ⩾55 years were selected from the Rotterdam Study, on the basis of the availability of radiographs of baseline and follow‐up.

Main outcome measures

Incidence of knee or hip osteoarthritis was defined as minimally grade 2 at follow‐up and grade 0 or 1 at baseline. The progression of osteoarthritis was defined as a decrease in joint space width.

Methods

x Rays of the knee and hip at baseline and follow‐up (mean follow‐up of 6.6 years) were evaluated. BMI was measured at baseline.

Results

A high BMI (>27 kg/m2) at baseline was associated with incident knee osteoarthritis (odds ratio (OR) 3.3), but not with incident hip osteoarthritis. A high BMI was also associated with progression of knee osteoarthritis (OR 3.2). For the hip, a significant association between progression of osteoarthritis and BMI was not found.

Conclusion

On the basis of these results, we conclude that BMI is associated with the incidence and progression of knee osteoarthritis. Furthermore, it seems that BMI is not associated with the incidence and progression of hip osteoarthritis.

Introduction

Lead (Pb) is known to affect bone, and recent evidence suggests that it has effects on cartilage as well. As osteoarthritis (OA) is a highly prevalent disease affecting bone and cartilage, we undertook the present analysis to determine whether whole blood Pb levels are associated with radiographic and symptomatic OA (rOA and sxOA, respectively) of the knee.

Methods

The analysis was conducted using cross-sectional data from the Johnston County Osteoarthritis Project, a rural, population-based study, including whole blood Pb levels, bilateral posteroanterior weight-bearing knee radiography and knee symptom data. rOA assessment included joint-based presence (Kellgren-Lawrence (K-L) grade 2 or higher) and severity (none, K-L grade 0 or 1; mild, K-L grade 2; moderate or severe, K-L grade 3 or 4), as well as person-based laterality (unilateral or bilateral). SxOA was deemed present (joint-based) in a knee on the basis of K-L grade 2 or higher with symptoms, with symptoms rated based on severity (0, rOA without symptoms; 1, rOA with mild symptoms; 2, rOA with moderate or severe symptoms) and in person-based analyses was either unilateral or bilateral. Generalized logit or proportional odds regression models were used to examine associations between the knee OA status variables and natural log-transformed blood Pb (ln Pb), continuously and in quartiles, controlling for age, race, sex, body mass index (BMI), smoking and alcohol drinking.

Results

Those individuals with whole blood Pb data (N = 1,669) had a mean (±SD) age of 65.4 (±11.0) years and a mean BMI of 31.2 (±7.1) kg/m2, including 66.6% women and 35.4% African-Americans, with a median blood Pb level of 1.8 μg/dl (range, 0.3 to 42.0 μg/dl). In joint-based analyses, for every 1-U increase in ln Pb, the odds of prevalent knee rOA were 20% higher (aOR, 1.20; 95% CI, 1.01 to 1.44), while the odds of more severe rOA were 26% higher (aOR, 1.26; 95% CI, 1.05 to 1.50, under proportional odds). In person-based analyses, the odds of bilateral rOA were 32% higher for each 1-U increase in ln Pb (aOR, 1.32; 95% CI, 1.03 to 1.70). Similarly for knee sxOA, for each 1-U increase in ln Pb, the odds of having sxOA were 16% higher, the odds of having more severe symptoms were 17% higher and the odds of having bilateral knee symptoms were 25% higher. Similar findings were obtained with regard to ln Pb in quartiles.

Conclusions

Increases in the prevalence and severity measures for both radiographically and symptomatically confirmed knee OA (although statistically significant only for rOA) were observed with increasing levels of blood Pb, suggesting that Pb may be a potentially modifiable environmental risk factor for OA.

Background

The purposes of the study were to determine the relevance and validity of in vivo non-invasive radiographic assessment of the CCLT (Cranial Cruciate Ligament Transection) rabbit model of osteoarthritis (OA) and to estimate the pertinence, reliability and reproducibility of a radiographic OA (ROA) grading scale and associated radiographic atlas.

Methods

In vivo non-invasive extended non weight-bearing radiography of the rabbit femorotibial joint was standardized. Two hundred and fifty radiographs from control and CCLT rabbits up to five months after surgery were reviewed by three readers. They subsequently constructed an original semi-quantitative grading scale as well as an illustrative atlas of individual ROA feature for the medial compartment. To measure agreements, five readers independently scored the same radiographic sample using this atlas and three of them performed a second reading. To evaluate the pertinence of the ROA grading scale, ROA results were compared with gross examination in forty operated and ten control rabbits.

Results

Radiographic osteophytes of medial femoral condyles and medial tibial condyles were scored on a four point scale and dichotomously for osteophytes of medial fabella. Medial joint space width was scored as normal, reduced or absent. Each ROA features was well correlated with gross examination (p < 0.001). ICCs of each ROA features demonstrated excellent agreement between readers and within reading. Global ROA score gave the highest ICCs value for between (ICC 0.93; CI 0.90-0.96) and within (ICC ranged from 0.94 to 0.96) observer agreements. Among all individual ROA features, medial joint space width scoring gave the highest overall reliability and reproducibility and was correlated with both meniscal and cartilage macroscopic lesions (rs = 0.68 and rs = 0.58, p < 0.001 respectively). Radiographic osteophytes of the medial femoral condyle gave the lowest agreements while being well correlated with the macroscopic osteophytes (rs = 0.64, p < 0.001).

Conclusion

Non-invasive in vivo radiography of the rabbit femorotibial joint is feasible, relevant and allows a reproducible grading of experimentally induced OA lesion. The radiographic grading scale and atlas presented could be used as a template for in vivo non invasive grading of ROA in preclinical studies and could allow future comparisons between studies.

Introduction

Although osteoarthritis (OA) commonly involves multiple joints, no widely accepted method for quantifying whole-body OA burden exists. Therefore, our aim was to apply factor analytic methods to radiographic OA (rOA) grades across multiple joint sites, representing both presence and severity, to quantify the burden of rOA.

Methods

We used cross-sectional data from the Johnston County Osteoarthritis Project. The sample (n = 2092) had a mean age of 65 ± 11 years, body mass index (BMI) 31 ± 7 kg/m2, with 33% men and 34% African Americans. A single expert reader (intra-rater κ = 0.89) provided radiographic grades based on standard atlases for the hands (30 joints, including bilateral distal and proximal interphalangeal [IP], thumb IP, metacarpophalangeal [MCP] and carpometacarpal [CMC] joints), knees (patellofemoral and tibiofemoral, 4 joints), hips (2 joints), and spine (5 levels [L1/2 to L5/S1]). All grades were entered into an exploratory common factor analysis as continuous variables. Stratified factor analyses were used to look for differences by gender, race, age, and cohort subgroups.

Results

Four factors were identified as follows: IP/CMC factor (20 joints), MCP factor (8 joints), Knee factor (4 joints), Spine factor (5 levels). These factors had high internal consistency reliability (Cronbach's α range 0.80 to 0.95), were not collapsible into a single factor, and had moderate between-factor correlations (Pearson correlation coefficient r = 0.24 to 0.44). There were no major differences in factor structure when stratified by subgroup.

Conclusions

The 4 factors obtained in this analysis indicate that the variables contained within each factor share an underlying cause, but the 4 factors are distinct, suggesting that combining these joint sites into one overall measure is not appropriate. Using such factors to reflect multi-joint rOA in statistical models can reduce the number of variables needed and increase precision.

Background

Seven polymorphisms in the matrilin‐3(MATN3) gene were previously tested for genetic association with hand osteoarthritis in an Icelandic cohort. One of the variants, involving a conserved amino acid substitution (T303M; SNP5), was related to idiopathic hand osteoarthritis.

Objectives

To investigate SNP5 and two other promising polymorphisms (rs2242190; SNP3, rs8176070; SNP6) for association with radiographic and symptomatic hand osteoarthritis phenotypes, as well as other heritable phenotypes.

Methods

Polymorphisms were examined in two distinct cohorts of subjects: a population based sample from the Rotterdam study (n = 809), and affected siblings from the genetics, osteoarthrosis and progression (GARP) study (n = 382).

Results

The originally described association of T303M with the hand osteoarthritis phenotype was not observed in the populations studied. In the Rotterdam sample, however, carrying the T allele of T303M conferred an odds ratio of 2.9 (95% confidence interval (CI), 1.2 to 7.3; p = 0.02) for spinal disc degeneration. In the GARP study, carriers of the A allele of SNP6 had an odds ratio of 2.0 (95% CI, 1.3 to 3.1, p = 0.004) for osteoarthritis of the first carpometacarpal joint (CMC1) as compared with the Rotterdam sample as a control group. Subsequent haplotype analysis showed that a common haplotype, containing the risk allele of SNP6, conferred a significant risk in sibling pairs with CMC1 osteoarthritis (odds ratio = 1.7 (95% CI, 1.1 to 2.7, p = 0.02)).

Conclusions

These associations suggest that the MATN3 region also determines susceptibility to spinal disc degeneration and CMC1 osteoarthritis.

OBJECTIVES—Different prevalences of generalised osteoarthritis (GOA) in patients with knee and hip OA have been reported. The aim of this investigation was to evaluate radiographic and clinical patterns of disease in a hospital based population of patient subgroups with advanced hip and knee OA and to compare the prevalence of GOA in patients with hip or knee OA, taking potential confounding factors into account.
METHODS—420 patients with hip OA and 389 patients with knee OA scheduled for unilateral total joint replacement in four hospitals underwent radiographic analysis of ipsilateral and contralateral hip or knee joint and both hands in addition to a standardised interview and clinical examination. According to the severity of radiographic changes in the contralateral joints (using Kellgren-Lawrence ⩾ grade 2 as case definition) participants were classified as having either unilateral or bilateral OA. If radiographic changes of two joint groups of the hands (first carpometacarpal joint and proximal/distal interphalangeal joints defined as two separate joint groups) were present, patients were categorised as having GOA.
RESULTS—Patients with hip OA were younger (mean age 60.4 years) and less likely to be female (52.4%) than patients with knee OA (66.3 years and 72.5% respectively). Intensity of pain and functional impairment at hospital admission was similar in both groups, while patients with knee OA had a longer symptom duration (median 10 years) compared with patients with hip OA (5 years). In 41.7% of patients with hip OA and 33.4% of patients with knee OA an underlying pathological condition could be observed in the replaced joint, which allowed a classification as secondary OA. Some 82.1% of patients with hip and 87.4% of patients with knee OA had radiographic changes in their contralateral joints (bilateral disease). The prevalence of GOA increased with age and was higher in female patients. GOA was observed more often in patients with knee OA than in patients with hip OA (34.9% versus 19.3%; OR=2.24; 95% CI: 1.56, 3.21). Adjustment for the different age and sex distribution in both patient groups, however, takes away most of the difference (OR=1.32; 95% CI: 0.89, 1.96).
CONCLUSION—The crude results confirm previous reports as well as the clinical impression of GOA being more prevalent in patients with advanced knee OA than in patients with advanced hip OA. However, these different patterns might be attributed to a large part to a different distribution of age and sex in these hospital based populations.

 Keywords: hip osteoarthritis; knee osteoarthritis; hand osteoarthritis; generalised osteoarthritis

INTRODUCTION:

Based on recent analyses, the measures of short-term responsiveness of MRI derived cartilage morphometry may not be as large as earlier studies had suggested. We examined if by selecting regions of interest with denuded cartilage, if the remaining cartilage within this region of interest was susceptible to greater rates of cartilage loss.

METHODS:

Subjects included for this analysis are a subset of the approximately 4700 participants in the Osteoarthritis Initiative (OAI) Study. Bilateral radiographs and 3T MRI (Siemens Trio) of the knees and clinical data are obtained at baseline and annually in all participants.150 subjects from the OAI Progression subcohort all of whom had both frequent symptoms and, in the same knee, radiographic osteoarthritis (ROA defined as definite tibio-femoral osteophytes on x-ray) based on a screening reading done at the OAI clinics. One knee from each subject was selected for analysis. Using sagittal 3D DESSwe MR images from the baseline and 12 follow-up month visit, a segmentation algorithm was applied to the cartilage plates of the index knee to compute the cartilage volume, normalized cartilage volume (Volume normalized to bone surface interface area), and percent denuded area (Total Cartilage Bone Interface area denuded of cartilage). Summary statistics of the changes (absolute and percentage) from baseline at one year and the standardized response mean (SRM), i.e. mean change divided by the standard deviation of that change were calculated. Analyses are stratified into three groups according to baseline assessment of denuded area: those with no denuded area in the region of interest at baseline, and then 2 groups (intermediate denuded area (≤median) and severe (> median) denuded area) of equal sample size.

RESULTS:

On average the subjects were 60.9 years of age and obese with a mean BMI of 30.3 kg/m2. For the combined central medial femur and tibia the mean volume change for the whole sample was −48.2 (SD 159.8) mm3, which gives an SRM of−0.30. In the subsample of knees with no denuded area the SRM was −0.25, in the knees with intermediate denuded area the SRM was −0.30, and in knees with severe denuded area the SRM was -1.00. For normalized volume of the central medial femur in the subsample of knees with no denuded area the SRM was −0.22, in the knees with intermediate denuded area the SRM was −0.26, and in knees with severe denuded area (n=23) the SRM was −0.71. The magnitude of the SRMs was generally smaller in participants with no denuded area. In contrast, the SRMs in participants with denuded area were larger. CONCLUSION: By selecting participants with the presence of cartilage regions with denuded area the ability to demonstrate change in cartilage loss in that specific location is markedly improved compared to persons without a full thickness lesion in that cartilage plate. This option for screening during recruitment in clinical trials could facilitate the detection of participants at greater risk of subsequent cartilage loss.

Objective

This study compared pain and function among African Americans and Whites with radiographic hip and/or knee osteoarthritis (OA), controlling for radiographic severity and other patient characteristics.

Methods

Participants were 1,368 individuals (32% African American) from the Johnston County Osteoarthritis Project with only knee OA, only hip OA, and both knee and hip OA. Linear regression models examined racial differences in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores and pain and function subscales, adjusting for radiographic severity, age, gender, education, body mass index (BMI), depressive symptoms, and WOMAC pain (last variable in models of function).

Results

Among those with only knee OA, African Americans had significantly worse mean WOMAC total scores than Whites (32.8 vs 24.3, p<0.001), and worse pain and function scores (p<0.001). Racial differences in WOMAC total, pain, and function scores persisted when controlling for radiographic severity and demographic factors but were not significant when also controlling for BMI and depressive symptoms. In models of WOMAC function, pain was the most strongly associated variable and substantially reduced the association of race with function. There were no racial differences in WOMAC scores among those with only hip OA or with both knee and hip OA.

Conclusion

Among participants with knee OA, racial differences in pain and function may be explained by BMI and depressive symptoms, and racial differences in function may also be largely influenced by pain. Improving management of weight and depressive symptoms may be key steps toward reducing racial disparities in knee OA symptoms.

The aim of our study was to determine the radiographic prevalence of hip and knee osteoarthritis and compare our results with prevalence data reported by other studies, as no similar study had been performed in Hungary previously. Our aim was also to investigate the usefulness of the different radiological scoring methods for the definition of osteoarthritis. Patients who earlier reported complaints and gave written consent were asked to participate in a clinical follow-up. In the 682 participants Harris hip score, visual analogue pain scale values for both joints, Knee Society score and knee functional score were calculated. Weight-bearing radiographs were taken of both joints. Kellgren-Lawrence radiological evaluation was performed and osteoarthritis prevalence was defined. Hip osteoarthritis was found in 109 cases (16.49%), and knee osteoarthritis was found in 111 cases (16.54%). Harris hip score, Knee Society score, functional score and visual analogue scale values were significantly worse in people with radiographically proven osteoarthritis compared to the control group (p < 0.05). Significantly higher osteoarthritis prevalence of both joints was found in those with increased body mass index values. Age also plays a significant role in the development of both hip and knee osteoarthritis. No significant difference was observed between male and female participants regarding osteoarthritis prevalence. The Kellgren-Lawrence score with a cut-off value of 2 or more is a useful evaluation method for the detection of osteoarthritis prevalence in epidemiological studies; according to our observations, in clinical practice a cut-off value of three or more is more relevant.

Objective: To investigate the prevalence and pattern of radiographic osteoarthritis (ROA) of the hand joints and its association with self reported hand pain and disability.

Methods: Baseline data on a population based study (age ⩾55 years) were used (n = 3906). Hand ROA was defined as the presence of Kellgren–Lawrence grade ⩾2 radiological changes in two of three groups of hand joints in each hand. The presence of hand pain during the previous month was defined as hand pain. The health assessment questionnaire was used to measure hand disability.

Results: 67% of the women and 54.8% of the men had ROA in at least one hand joint. DIP joints were affected in 47.3% of participants, thumb base in 35.8%, PIP joints in 18.2%, and MCP joints in 8.2% (right or left hand). ROA of other joint groups (right hand) co-occurred in 56% of DIP involvement, 88% of PIP involvement, 86% of MCP involvement, and 65% of thumb base involvement. Hand pain showed an odds ratio of 1.9 (1.5 to 2.4) with the ROA of the hand (right). Hand disability showed an odds ratio of 1.5 (1.1 to 2.1) with ROA of the hand (right or left).

Conclusions: Hand ROA is common in the elderly, especially in women. Co-occurrence of ROA in different joint groups of the hand is more common than single joint disease. There is a modest to weak association between ROA of the hand and hand pain/disability, varying with the site of involvement.