Smoking and osteoarthritis: is there an association? The Clearwater Osteoarthritis Study

The Predictors of Osteoarthritis Among U.S. Adults: National Health and Nutrition Examination Survey, 2005 to 2018

Background Osteoarthritis (OA) is a leading cause of disability in the United States (U.S.) population, and its prevalence continues to rise. Traditionally, extreme joint loading was described as the leading cause of OA; however, recent studies suggest OA may arise from more complex mechanisms. This study aimed to identify the association between OA and various health predictors among U.S. adults. Methods National Health and Nutrition Examination Survey (NHANES) data of adult participants from 2005 to 2018 was reviewed. OA diagnosis was patient-reported, and other health variables were assessed based on patient-reported, laboratory, and examination data. A multivariable survey logistic regression model was used to estimate adjusted odds ratios and confidence intervals (95% CIs). Stratified analysis based on BMI category was additionally performed to assess the modifying effect of obesity on the association between OA and health predictors. Results A total of 42,143 participants were included in this study. OA prevalence was highest in patients ages [Formula: see text] 65 years, females, non-obese individuals, non-Hispanic Whites, and those with at least college education. After controlling for multiple confounding demographic variables and comorbidities, the odds of OA increased with aging, female sex, obesity, high cholesterol, hypertension, diabetes, depression, and thyroid disease. Non-Hispanic White patients and those with less than a high school education also had higher odds of OA. After stratified analysis, aging, female sex, and severe depression demonstrated similar associations with OA across each BMI strata. Having at least a college-level education additionally conferred a similar association with OA across each BMI strata. Conclusion The odds of OA increased with aging, female sex, obesity, less than high school education, high cholesterol, hypertension, diabetes, depression, and thyroid disease. Further studies are needed to characterize the mechanisms of these associations. Given the myriad of factors that influence OA development and progression, the utilization of multidisciplinary and holistic care of OA patients is recommended to limit the influence of other health predictors and reduce ensuing pain, disability, and other complications that result from OA.

Lifestyle behaviour changes associated with osteoarthritis: a prospective cohort study

The aim of this prospective cohort study was to compare changes in lifestyle behaviours over nine years in women who were and were not diagnosed with osteoarthritis (OA). Data were from the 1945-51 cohort of the Australian Longitudinal Study on Women's Health (aged 50-55 in 2001) who completed written surveys in 2001, 2004, 2007 and 2010. The sample included 610 women who were, and 3810 women who were not diagnosed with OA between 2004 and 2007. Descriptive statistics were used to assess changes in lifestyle behaviours (weight, sitting time, physical activity, alcohol and smoking) in the two groups, over three survey intervals: from 2001-2004 (prior to diagnosis); from 2004-2007 (around diagnosis); and from 2007-2010 (following diagnosis). Compared with women without OA (28%), a greater proportion of women with OA (38%) made at least one positive lifestyle change (p < 0.001). These included losing > 5 kg (9.8% vs. 14.4%, p < 0.001), and reducing sitting time by an hour (29.5% vs. 39.1%, p < 0.001) following diagnosis. However, women with OA also made negative lifestyle changes (35% vs. 29%, p < 0.001), for example, gaining > 5 kg around the time of diagnosis (21.4% vs. 14.5%, p < 0.001) and increasing sitting time by an hour following diagnosis (38.4% vs. 32.3%, p = 0.003). More women with OA also started smoking following diagnosis (8.9% vs. 0.8%, p < 0.001). While some women made positive changes in lifestyle behaviours during and following OA diagnosis, others made negative changes. Consistent support from clinicians for managing OA symptoms may enable patients to make more positive changes in lifestyle behaviours.

Alshahrani A, Prabahar K, Veeramani VP, Amirthalingam P, F. Alqifari S, Mani V, Viswanath Reddy LK. An evaluation of knee osteoarthritis pain in the general community-Asir region, Saudi Arabia

BACKGROUND

Knee osteoarthritis (KOA) is one of the most common conditions resulting in disability, particularly in the elderly population. Osteoarthritis (OA) is the most common articular disease and the leading cause of chronic disability in the developed world.

OBJECTIVE

This study was carried out to evaluate knee pain in the Asir region of Saudi Arabia. An analytical cross-sectional survey design was adopted in the Asir region from April 2023 to August 2023 to assess the knee pain of the adult population using an anonymous online questionnaire.

RESULTS

Of 1234, 332 were men (26.90) and 902 were women (73.09). WOMAC index score category 55.34% (n = 683) of the subjects had a low risk (score <60), 28.68% (n = 354) had a moderate risk (score 60-80), and 15.96% (n = 197) had a high risk (score ≥81) for KOA. According to clinical criteria, 79.33% (n = 979) of the study subjects had OA. Age group, gender 2.17 (1. 67-2.82) [OR 2.17; 95% CI 1.67-2.82), family history of OA [OR 0.47; 95% CI 0.37-0.62], diabetes [OR 2.78; 95% CI 2.17-3.56], hypertension [OR 0.35; 95% CI 0.26-0.45] were significantly associated with the percentage of the WOMAC index score using the Chi-square test analysis (P<0.05). Therefore, the WOMAC index showed higher diagnostic precision with a statistically significant association [OR 9.31 CI 6.90-12.81] with a P< 0.0001.

CONCLUSION

KOA is more common in older, obese people who have reached the age of 50 in the Asir region, and it is more prevalent in women. Alarms the need for appropriate awareness programs for better disease prevention and health outcomes for the benefit of the community through general public health programs.

The associations of implant and patient factors with migration of the tibial component differ by sex : a radiostereometric study on more than 400 total knee arthroplasties

AIMS

Thresholds of acceptable early migration of the components in total knee arthroplasty (TKA) have traditionally ignored the effects of patient and implant factors that may influence migration. The aim of this study was to determine which of these factors are associated with overall longitudinal migration of well-fixed tibial components following TKA.

METHODS

Radiostereometric analysis (RSA) data over a two-year period were available for 419 successful primary TKAs (267 cemented and 152 uncemented in 257 female and 162 male patients). Longitudinal analysis of data using marginal models was performed to examine the associations of patient factors (age, sex, BMI, smoking status) and implant factors (cemented or uncemented, the size of the implant) with maximum total point motion (MTPM) migration. Analyses were also performed on subgroups based on sex and fixation.

RESULTS

In the overall group, only fixation was significantly associated with migration (p < 0.001). For uncemented tibial components in males, smoking was significantly associated with lower migration (p = 0.030) and BMI approached significance (p = 0.061). For females with uncemented components, smoking (p = 0.081) and age (p = 0.063) approached significance and were both associated with increased migration. The small number of self-reported smokers in this study warrants cautious interpretation and further investigation. For cemented components in females, larger sizes of tibial component were significantly associated with increased migration (p = 0.004). No factors were significant for cemented components in males.

CONCLUSION

The migration of uncemented tibial components was more sensitive to patient factors than cemented implants. These differences were not consistent by sex, suggesting that it may be of value to evaluate female and male patients separately following TKA. Cite this article: Bone Joint J 2022;104-B(4):444-451.

Does smoking cessation increase risk of knee replacement? a general population-based cohort study

OBJECTIVE

Smoking represents a major issue for global public health. Owing to methodologic challenges, findings of an association between smoking and risk of knee osteoarthritis (OA) are inconsistent. We sought to assess the relation of onset of smoking cessation to the risk of OA sequelae, i.e., knee replacement, and to perform sub-cohort analysis according to weight change after smoking cessation.

DESIGN

Using The Health Improvement Network, we conducted a cohort study to examine the association between smoking cessation and risk of knee replacement among patients with knee OA. Participants who stopped smoking were further grouped into three sub-cohorts: weight gain (body mass index [BMI] increased>1.14 kg/m²), no substantial weight change (absolute value of BMI change<1.14 kg/m²), and weight loss (BMI loss>1.14 kg/m²) after smoking cessation.

RESULTS

We identified 108 cases of knee replacement among 1,054 recent quitters (26.7/1,000 person-years) and 1,108 cases among 15,765 current smokers (17.4/1,000 person-years). The rate difference of knee replacement in recent quitter cohort vs current smoker cohort was 10.4 (95% confidence interval [CI]:5.3-15.6)/1,000 person-years and the adjusted hazard ratio (HR) was 1.30 (95%CI:1.05-1.59). Compared with current smokers, risk of knee replacement was higher among quitters with weight gain (HR = 1.42,95%CI:1.01-1.98), but not among those with no substantial weight change (HR = 1.29,95%CI:0.90-1.83) or those with weight loss (HR = 1.11,95%CI:0.71-1.75).

CONCLUSIONS

Our large population-based cohort study provides the first evidence that smoking cessation was associated with a higher risk of knee replacement among individuals with knee OA, and such an association was due to weight gain after smoking cessation.

A comparison of risk factors for osteo- and rheumatoid arthritis using NHANES data

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Both osteo- and rheumatoid arthritis increase with age.

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Osteoarthritis is more common in whites, but rheumatoid arthritis is in blacks.

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Obesity and female sex increase risk of risk of both osteo- and rheumatoid arthritis.

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Smoking increases risk of both forms of arthritis in women.

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These two forms of arthritis have many common risk factors.

Osteoarthritis and rheumatoid arthritis are both diseases of joints, but they have very different etiologies. Osteoarthritis is a disease assumed to result from wear and tear over time, whereas rheumatoid arthritis is an autoimmune disease where the body’s immune system attacks joint tissues. Using NHANES data (1999–2015), we have compared the influence of age, sex, ethnicity, body mass index and smoking on these two very different forms of arthritis. Incidence of both increases with age and are more frequent in females than males. There is little apparent difference between osteoarthritis and rheumatoid arthritis in women of normal as comparted to overweight, but both are more frequent in obese women, especially those over the age of 60. While osteoarthritis is more frequent in whites, blacks have more rheumatoid arthritis, and Hispanics show an intermediate prevalence. Smoking significantly increased the incidence of both osteoarthritis and rheumatoid arthritis in women, but increased prevalence of only RA in men. There was no effect of smoking on OA prevalence in males. It is remarkable that two diseases of joints, which have quite different causes, should have so many commonalities. The differences that exist appear to be due to a combination of inflammatory markers and access to health care.

Impact of smoking on femorotibial and hip osteoarthritis progression: 3-year follow-up data from the KHOALA cohort

OBJECTIVES

To evaluate the clinical and structural impact of smoking on knee and hip osteoarthritis at baseline and after 3years.

METHODS

Observational data on the progressive effects of smoking at baseline and after 3years were collected from The Knee and Hip Osteoarthritis Long-Term Assessment cohort comprising a French population of patients aged 40-75years with symptomatic lower limb osteoarthritis. Clinical (the Western Ontario and McMaster Universities Arthritis Index and Harris scores) and structural (radiography for osteophyte detection and joint-space narrowing assessment) were conducted. The tobacco usage categories were 'never smoker', 'former smoker', and 'current smoker'.

RESULTS

Of the 873 subjects included, 215 (25%) were former smokers and 119 (14%) were current smokers. Multivariate analyses revealed that former and current smokers had fewer knee osteophytes in the medial compartment at baseline (odds ratio [OR]=0.64 [0.41-0.99] and 0.63 [0.36-1.11], respectively), lower osteophyte development in the lateral condyle after 3years (OR=011 [0.03-0.45] and 0.15 [0.03-0.97]), and lower osteophyte development in the lateral tibial plateau after 3years (OR=0.22 [0.06-0.75] and 0.68 [0.14-3.35]). Higher tobacco consumption and longer duration of consumption were significantly associated with fewer knee osteophytes at baseline and lower osteophyte development at 3years.

CONCLUSION

Although cigarette smoking did not influence knee function, pain, or the need for replacement surgery, current and former smokers developed fewer osteophytes. This relationship may be linked to the quantity and duration of consumption. Our results provide further insight into the smoking-related pathophysiology of osteoarthritis.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.

Cigarette smoking and knee osteoarthritis in the elderly: Data from the Korean National Health and Nutritional Examination Survey

BACKGROUND

The relationship between smoking and osteoarthritis (OA) has not been investigated in a large-scale study. The aim of this study was to examine the relationship between smoking and knee OA in the elderly.

METHODS

This study included 5117 subjects aged >60 years who responded to questionnaires on their history of smoking and knee OA diagnosed by a physician taken from the Korean National Health and Nutritional Examination Survey (KNHANES-VI) 2013-2015. We classified all 5117 subjects into 2 groups (the OA group and non-OA group) and compared the demographics and characteristics between the 2 groups. A multivariate logistic regression analysis was conducted to investigate the possible association between knee OA and smoking.

RESULTS

The prevalence of current smoking in the OA group (5.1%) was significantly lower than in the non-OA group (14.6%; p < 0.001). Furthermore, the proportion of moderate smokers who smoked >10 cigarettes per day or heavy smokers who smoked >20 cigarettes per day was significantly higher in the non-OA group. In the multivariate analysis, current smoking history was a preventative factor for the prevalence of OA in a multivariate model that included age, sex, body mass index, waist circumference (OR: 0.752, 95% CI: 0.571-0.989, p = 0.042).

CONCLUSIONS

This large-scale national study highlights an inverse association between smoking and the prevalence of knee OA in the general Korean elder adult population, primarily in males. Further investigation of this relationship between smoking and knee OA is needed to determine smoking's specific mechanism of protection against knee OA.

Household air pollution and arthritis in low-and middle-income countries: Cross-sectional evidence from the World Health Organization's study on Global Ageing and Adult Health

Background

Evidence points to a clear link between air pollution exposure and several chronic diseases though investigations regarding arthritis are still lacking. Emerging evidence suggests an association between ambient air pollution and rheumatoid arthritis. Household air pollution exposure, conversely, is largely unstudied but may be an important consideration for arthritis, particularly in low- and middle-income countries (LMICs), where cooking and heating activities can generate high indoor air pollutant levels.

Methods

We investigated the association of household air pollution (electricity vs. gas; kerosene/paraffin; coal/charcoal; wood; or agriculture/crop/animal dung/shrubs/grass as the main fuel used for cooking) and arthritis in six LMICs (China, Ghana, India, Mexico, the Russian Federation, South Africa) using data from Wave I of the World Health Organization Study on Global AGEing and Adult Health (SAGE) (2007–2010). Multivariable analyses were adjusted for sociodemographic, household and lifestyle characteristics and several comorbidities.

Results

The use of gas (aOR = 1.76, 95%CI: 1.40–2.21); coal (aOR = 1.74, 95%CI: 1.22–2.47); wood (aOR = 1.69, 95%CI: 1.30–2.19); or agriculture/crop/animal dung/shrubs/grass: aOR = 1.95 (1.46–2.61) fuels for cooking were strongly associated with an increased odds of arthritis, compared to electricity in cluster and stratified adjusted analyses. Gender (female), age (≥50 years), overweight (25.0 ≤BMI<30.0 kg/m²), obesity (BMI ≥30.0 kg/m²), former and current alcohol consumption, and the comorbidities angina pectoris, diabetes, chronic lung disease, depression and hypertension were also associated with a higher odds of arthritis. Underweight (BMI<18.5 kg/m²) and higher education levels (college/university completed/post-graduate studies) were associated with a lower odds of arthritis.

Conclusions

These findings suggest that exposure to household air pollution from cook fuels is associated with an increased odds of arthritis in these regions, which warrants further investigation.

The association between smoking and knee osteoarthritis in a cohort of Danish patients undergoing knee arthroscopy

Background

It has been suggested that smoking is associated with reduced risk of knee osteoarthritis (OA). However, supplementary studies are needed to further investigate any such potential association. Thus, our aim was to examine the relationship between smoking and early or more established knee OA in a cohort of relatively young patients with meniscal tears.

Methods

This cross-sectional study included 620 participants from the Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing knee arthroscopy for a meniscal tear (mean age 49.2 (18.0–76.8) years). Recruitment of patients was performed between February 1, 2013, and January 31, 2015, at four different hospitals in Denmark. We defined early or more established knee OA as the combination of patient-reported frequent knee pain, degenerative meniscal tissue and presence of cartilage defects assessed by the operating surgeons. The relationship between smoking status and knee OA was examined by risk ratio (RR) with a 95% confidence interval (CI), estimated from logistic regression adjusted for age, sex, BMI, education, work status and level of physical activity.

Results

The prevalence of early or more established knee OA was 37.7% in current smokers and 45.0% in non-smokers. We found no statistically significant association between current smoking and knee OA (adjusted RR 1.09, 95% CI 0.91–1.30).

Conclusions

This study found no relationship between current smoking and early or more established knee OA in a cohort of patients undergoing arthroscopic meniscal surgery. Thus, the inverse association between smoking and knee OA that has been suggested by previous studies was not confirmed.

Quadriceps muscle weakness is related to increased risk of radiographic knee OA but not its progression in both women and men: the Matsudai Knee Osteoarthritis Survey

PURPOSE

The purpose of this study was to investigate the causal relationship between quadriceps muscle strength and radiographic knee osteoarthritis (OA) in a longitudinal study.

METHODS

The present study included 976 knees from 488 subjects who participated in both the 5th (2007) and 7th (2013) surveys of the Matsudai Knee Osteoarthritis Survey. Bilateral quadriceps strengths of each subject were measured using the quadriceps training machine (QTM-05F, Alcare Co., Ltd., Tokyo, Japan). Additionally, weight-bearing standing knee radiographs were obtained, and knee OA was graded according to the Kellgren-Lawrence classification system. The relationships between quadriceps strength and the incidence and progression of radiographic knee OA were assessed using multiple logistic regression analysis.

RESULTS

After adjusting for age and body mass index (BMI), both female and male knees in the lowest quantile of quadriceps strength had higher risk of the incidence of radiographic knee OA compared with the highest quantile of quadriceps strength (women: OR 2.414, 95% CI 1.098-5.311; men: OR 2.774, 95% CI 1.053-7.309). In contrast, after adjusting for age, BMI and femorotibial angle, both female and male knees in the lowest quantile compared with the highest quantile of quadriceps strength did not differ in risk of the progression of radiographic knee OA (women: OR 1.040, 95% CI 0.386-2.802; men: OR 2.814, 95% CI 0.532-14.898).

CONCLUSION

Quadriceps muscle weakness was related to increased risk of the incidence of radiographic knee OA, but not its progression, in both women and men. Therefore, the clinically important finding of this study is that, in both women and men, maintaining higher quadriceps muscle strength may be one of the most effective prevention methods for incident radiographic knee OA.

LEVEL OF EVIDENCE

II.

The Prevalence, Incidence, and Progression of Hand Osteoarthritis in Relation to Body Mass Index, Smoking, and Alcohol Consumption

OBJECTIVE

To estimate the extent that overweight/obesity, smoking, and alcohol are associated with prevalence and longitudinal changes of radiographic hand osteoarthritis (OA).

METHODS

Participants from the Osteoarthritis Initiative (n = 1232) were included, of whom 994 had 4-year followup data. In analyses on incident hand OA, only persons without hand OA at baseline were included (n = 406). Our exposure variables were overweight/obesity [body mass index (BMI), waist circumference], smoking (current/former, smoking pack-yrs), and alcohol consumption (drinks/week). Using linear and logistic regression analyses, we analyzed possible associations between baseline exposure variables and radiographic hand OA severity, erosive hand OA, incidence of hand OA, and radiographic changes. Analyses were adjusted for age, sex, and education.

RESULTS

Neither overweight nor obesity were associated with hand OA. Current smoking was associated with less hand OA in cross-sectional analyses, whereas longitudinal analyses suggested higher odds of incident hand OA in current smokers (OR 2.20, 95% CI 1.02-4.77). Moderate alcohol consumption was associated with higher Kellgren-Lawrence sum score at baseline (1-3 drinks: 1.55, 95% CI 0.43-2.67) and increasing sum score during 4-year followup (4-7 drinks: 0.33, 95% CI 0.01-0.64). Moderate alcohol consumption (1-7 drinks/week) was associated with 2-fold higher odds of erosive hand OA, which was statistically significant. Additional adjustment for BMI gave similar strengths of associations.

CONCLUSION

Overweight/obesity were not associated with hand OA. Contrasting results were observed for smoking and hand OA, suggesting lack of association. Moderate alcohol consumption was associated with hand OA severity, radiographic changes, and erosive hand OA, warranting further investigation.

Association between smoking and risk of knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between smoking and the risk for knee osteoarthritis (OA).

DESIGN

Cohort, case-control, and cross-sectional studies were obtained from the Medline, Embase, and Web of Science databases. Estimates were calculated using a random-effects model. Subgroup analyses and meta-regression models were performed to investigate potential sources of heterogeneity. We further analyzed the dose-response relationship between cigarette consumption and risk of knee OA.

RESULTS

Thirty-eight independent observational studies that included 481,744 participants were analyzed. Those who had ever smoked had a significantly decreased risk of developing knee OA relative to those who had never smoked (RR = 0.80; 95% CI 0.73-0.88). This was unaffected by study design, and the pooled relative risks (RRs) were 0.79 (95% CI, 0.65-0.96), 0.71 (95% CI, 0.61-0.84) and 0.83 (95% CI, 0.73-0.94) for cohort, case-control, and cross-sectional studies, respectively. Analysis of subgroups stratified by gender reduced the heterogeneity from moderate to low in both males and females. The lower risk for developing knee OA was more apparent in male smokers (RR = 0.69; 95% CI 0.58-0.80) than female smokers (RR = 0.89; 95% CI 0.77-1.02) and dose-response analysis showed a linear decrease in knee OA with increased cigarette consumption.

CONCLUSIONS

We found an inverse association between cigarette smoking and risk of knee OA, irrespective of study design. This association was more apparent in males. However, we have not demonstrated a causal relationship between smoking and OA, and further investigations are needed.

Low Skeletal Muscle Mass in the Lower Limbs Is Independently Associated to Knee Osteoarthritis

Objectives

It has been reported that low skeletal muscle mass correlates with knee osteoarthritis in obese individuals. This study aimed to investigate whether lower limb skeletal muscle mass is independently associated with knee osteoarthritis in the general population.

Materials and Methods

This cross-sectional study used public data from the Fourth and Fifth Korean National Health and Nutrition Examination Survey. Subjects included 4924 community-dwelling adults aged ≥50 years (821 subjects with knee osteoarthritis and 4,103 controls). Skeletal muscle mass index (SMI) was calculated from the appendicular skeletal muscle mass measured by dual energy X-ray absorptiometry. Independent effects of total and lower limb SMI values on knee osteoarthritis were determined using odds ratios (OR) adjusted for age, sex, obesity, total femur bone mineral density, serum vitamin D level, diabetes mellitus status, and physical activity on multivariate logistic regression analysis.

Results

The adjusted logistic regression model revealed that older age, female sex, and obesity were significantly associated with knee osteoarthritis. A higher serum vitamin D level was also positively correlated with knee osteoarthritis (OR, 1.015; 95% CI, 1.003–1.027; P = 0.010). Although total SMI was not significantly associated with knee osteoarthritis (OR, 0.976; 95% CI, 0.946–1.007; P = 0.127), a low lower limb SMI had an independent effect on knee osteoarthritis (OR, 0.941; 95% CI, 0.900–0.983; P = 0.006).

Conclusions

Low skeletal muscle mass in the lower limbs but not in the whole body was independently associated with knee osteoarthritis.

Association between direct and indirect smoking and osteoarthritis prevalence in Koreans: a cross-sectional study

OBJECTIVES

To assess the association between smoking patterns and knee and hip joint osteoarthritis (OA) prevalence in Koreans aged 50 years or older with focus on knee OA.

DESIGN

Cross-sectional study using nationally representative data.

SETTING

Data were collected at portable Health Examination Centres in Korea.

PARTICIPANTS

Data of 9064 participants of the 5th Korean National Health and Nutrition Examination Survey (2010-2012) aged 50 years or older who received knee or hip joint X-rays out of 31,596 total surveyees were analysed.

PRIMARY OUTCOME MEASURES

OA prevalence by smoking behaviour (current smoking, past smoking, indirect smoking and non-smoking).

SECONDARY OUTCOME MEASURES

Estimated risk of OA by smoking amount, period, pack-years and indirect smoking exposure time to assess the association between smoking-related factors and knee OA by calculating ORs and adjusting for covariates in a complex sampling design. A multinomial logistic regression analysis and backward elimination method was used.

RESULTS

OA prevalence in Koreans aged 50 years or older was 13.9%, with prevalence about 3.5 times higher in women (men 5.7%, women 20.1%). ORs for knee and hip joint OA prevalence by smoking behaviour in male indirect-smokers were lower than those in non-smokers in age and sex (OR 0.271; 95% CI 0.088 to 0.828), and selective adjustments (OR 0.314; 95% CI 0.102 to 0.966). All other analyses for smoking behaviour and total OA prevalence, and knee OA prevalence were not significantly different. Associations between smoking amount, period, pack-years and knee OA prevalence were non-significant in ever-smokers. Associations between indirect smoking exposure time and knee OA prevalence were also non-significant.

CONCLUSIONS

This study found that though direct and previous smoking and OA prevalence were not associated, there was a weak relationship between indirect smoking and OA.

Current evidence on risk factors for knee osteoarthritis in older adults: a systematic review and meta-analysis

Osteoarthritis (OA) is a leading cause of pain and disability and leads to a reduced quality of life. The aim was to determine the current evidence on risk factors for onset of knee pain/OA in those aged 50 and over. A systematic review and meta-analysis was conducted of cohort studies for risk factors for the onset of knee pain. Two authors screened abstracts and papers and completed data extraction. Where possible, pooled odds ratios (OR) were calculated via random effects meta-analysis and population attributable fractions (PAFs) derived. 6554 papers were identified and after screening 46 studies were included. The main factors associated with onset of knee pain were being overweight (pooled OR 1.98, 95% confidence intervals (CI) 1.57-2.20), obesity (pooled OR 2.66 95% CI 2.15-3.28), female gender (pooled OR 1.68, 95% CI 1.37-2.07), previous knee injury (pooled OR 2.83, 95% CI 1.91-4.19). Hand OA (pooled OR 1.30, 95% CI 0.90-1.87) was found to be non-significant. Smoking was found not to be a statistically significant risk or protective factor (pooled OR 0.92, 95% CI 0.83-1.01). PAFs indicated that in patients with new onset of knee pain 5.1% of cases were due to previous knee injury and 24.6% related to being overweight or obese. Clinicians can use the identified risk factors to identify and manage patients at risk of developing or increasing knee pain. Obesity in particular needs to be a major target for prevention of development of knee pain. More research is needed into a number of potential risk factors.

Iatrogenic contributions to cervical adjacent segment pathology: review article

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is widely accepted as a predictably excellent procedure. On the other hand, adjacent level pathology following ACDF is a well-known phenomenon which undercuts surgical outcome. However, the extent to which ACDF accelerates this phenomenon in the naturally degenerating cervical spine is still to be understood.

QUESTIONS/PURPOSES

To summarize the current evidence concerning adjacent segment pathology in the light of biomechanics, natural history, postoperative course, and comparison between ACDF and total disc replacement (TDR).

METHODS

This is a study of published articles. Articles were searched by the topic of adjacent disc pathology in cervical spine through Google Scholar and Pubmed. After review, 37 published articles were deemed suitable for the subject of this study.

RESULTS

Biomechanical and clinical data strongly suggest that ASP is a presentation of the iatrogenically accelerated natural aging process of cervical spine. However, power study analysis with assumption showed that current RCTs are unlikely to prove this suggestion.

CONCLUSION

Available data suggests that iatrogenic factors play a significant role in adjacent segment pathology following ACDF.

Relationship between cigarette smoking and radiographic knee osteoarthritis in Chinese population: a cross-sectional study

The purpose of this paper was to estimate the cross-sectional association between cigarette smoking and radiographic knee Osteoarthritis (OA) in Chinese population. A total of 3,789 subjects (1,796 females and 1,993 males) participated in this study. A subject was diagnosed with radiographic knee OA if Kellgren-Lawrence (K-L) grade ≥2 in at least one leg. The smoking status was classified into four levels based on the daily smoking habit: (1) 0/day; (2) 1-10/day; (3) 11-20/day; and (4) >20/day. Linear trend and multivariable logistic regression were conducted for statistical analysis. The prevalence of radiographic knee OA was 28.4 % among the subjects of this study. An inverse association was observed between cigarette smoking and radiographic knee OA in the linear trend test. Such association remained valid after adjusting the factors of age, gender, body mass index, betel quilt chewing status, physical activity, alcohol drinking status, mean total energy intake and educational level in the multivariable logistic regression. This study suggested a negative association between cigarette smoking and radiographic knee OA in the Chinese population. The findings of this study need to be confirmed by further prospective research.

Adjacent segment disease after anterior cervical interbody fusion: a multicenter retrospective study of 288 patients with long-term follow-up

INTRODUCTION

Cervical discectomy with interbody fusion is a common procedure in spinal surgery. The resultant biomechanical alterations accelerate degeneration of the adjacent segment, but the contribution of natural degeneration to adjacent segment disease is unclear.

OBJECTIVE

To assess the long-term rate of surgery to discs adjacent to cervical interbody fusion; and to assess the associated incidence of cervico-brachial neuralgia and radiological degeneration of adjacent discs.

MATERIAL AND METHOD

A multicenter retrospective study included anterior cervical discectomy patients at a minimum of 10 years' follow-up. Clinical variables comprised pain, use of analgesics and surgical revision. Functional assessment was performed on the Neck Disability Index (NDI). Radiologic degeneration was assessed on the Goffin score based on cervical spine X-ray.

RESULTS

Two hundred and eighty-eight patients were contacted and filled out the clinical questionnaire. Among the patients, 153 underwent radiological reassessment. Mean age was 46 years (range, 16-73 years). Mean follow-up was 14.5 years (12-18 years). The rate of surgical revision on a disc adjacent to the primary level was 5.9%. Frequent attacks of cervico-brachial neuralgia were reported in 20.5% of cases. Radiologic adjacent segment degeneration was found in 81.3% of cases over follow-up. There was a significant correlation between degree of radiologic adjacent segment degeneration and NDI (P=0.02).

DISCUSSION

Degeneration adjacent to discectomy/fusion is partly due to aging. The present findings, however, agree with the literature and indicate accelerated degeneration in adjacent segments. These findings should be taken into account in treatment decision-making and suggest a possible interest of more physiological surgery such as arthroplasty.

LEVEL OF EVIDENCE

IV - Multicenter retrospective study.

Risk factors for knee replacement due to primary osteoarthritis, a population based, prospective cohort study of 315,495 individuals

BACKGROUND

Osteoarthritis (OA) of the knee is a common and disabling condition. We wanted to investigate the modifiable risk factors Body Mass Index (BMI) and physical activity, using knee replacement (KR) as a marker for severely symptomatic disease, focusing on the interaction between these risk factors.

METHODS

315,495 participants (mean age 43.0 years) from national health screenings were followed prospectively with respect to KR identified by linkage to the Norwegian Arthroplasty Register. Data were analysed by Cox proportional hazard regression.

RESULTS

During 12 years of follow up 1,323 individuals received KR for primary OA. There was a dose-response relationship between BMI and heavy labour, and later KR. Comparing the highest versus the lowest quarter of BMI, the relative risk was 6.2 (95% CI: 4.2-9.0) in men and 11.1 (95% CI: 7.8-15.6) in women. Men reporting intensive physical activity at work had a relative risk of 2.4 (95% CI: 1.8-3.2) versus men reporting sedentary activity at work, the corresponding figure in women being 2.3 (95% CI: 1.7-3.2). The effect of BMI and physical activity at work was additive. The heaviest men with the most strenuous work had a RR of 11.7 (95% CI: 5.9-23.1) compared to the ones with the lowest BMI and most sedentary work. For women the corresponding RR was 15.8 (95% CI: 8.2-30.3). There was no association between physical activity during leisure and KR.

CONCLUSION

We found that a high BMI and intensive physical activity at work both contribute strongly to the risk of having a KR. As the two risk factors seem to act independently, people with strenuous physical work with a high BMI are at particularly high risk for severely disabling OA of the knee, and should be targeted with effective preventive measures.

Cigarette smoking and risk of total knee replacement for severe osteoarthritis among Chinese in Singapore--the Singapore Chinese health study

PURPOSE

Data on the effects of cigarette smoking with osteoarthritis (OA) are inconsistent and no study has examined the effect of smoking cessation. We examined smoking status, duration, dosage and cessation in association with risk of total knee replacement (TKR) for severe knee OA among elderly Chinese in Singapore.

METHODS

We used data from the Singapore Chinese Health Study, a population-based prospective cohort of 63,257 Chinese men and women aged 45-74 years during enrollment between 1993 and 1998. Detailed information on smoking, current diet and lifestyle factors were obtained through in person interviews. As of 31 December 2011, 1,973 incident TKR cases for severe knee OA had been identified via linkage with nationwide hospital discharge database. We used Cox regression methods to examine smoking in relation to TKR risk with adjustment for age, gender, education, body mass index (BMI), comorbidities and physical activity level.

RESULTS

Compared to never smokers, current smokers had a 51% decrease in risk of TKR [Hazards ratio (HR) = 0.49; 95% confidence interval (CI) = 0.40-0.60]. Among current smokers, there was a very strong dose-dependent association between increasing duration and dosage of smoking with decreasing risk of TKR (P for trend <0.0001). Among former smokers, there was a dose-dependent response between decrease in duration of smoking cessation and reduction in TKR risk (P for trend = 0.034).

CONCLUSION

Our findings strongly implicate smoking as a protective factor for TKR indicated for severe knee OA. This concurs with experimental data that nicotine promotes proliferation and collagen synthesis in chondrocytes.

Use of thoracic spine thrust manipulation for neck pain and headache in a patient following multiple-level anterior cervical discectomy and fusion: a case report

STUDY DESIGN

Case report.

BACKGROUND

Thoracic spine thrust manipulation has been shown to be an effective intervention for individuals experiencing mechanical neck pain.

CASE DESCRIPTION

The patient was a 46-year-old woman referred to outpatient physical therapy 2 months following multiple-level anterior cervical discectomy and fusion. At initial evaluation, primary symptoms consisted of frequent headaches, neck pain, intermittent referred right elbow pain, and muscle fatigue localized to the right cervical and upper thoracic spine regions. Initial examination findings included decreased passive joint mobility of the thoracic spine, limited cervical range of motion, and limited right shoulder strength. Outcome measures consisted of the numeric pain rating scale, the Neck Disability Index, and the global rating of change scale. Treatment consisted of a combination of manual therapy techniques aimed at the thoracic spine, therapeutic exercises for the upper quarter, and patient education, including a home exercise program, over a 6-week episode of care.

OUTCOMES

Immediate reductions in cervical-region pain (mean ± SD, 2.0 ± 1.1) and headache (2.0 ± 1.3) intensity were reported every treatment session immediately following thoracic spine thrust manipulation. At discharge, the patient reported 0/10 cervical pain and headache symptoms during all work-related activities. From initial assessment to discharge, Neck Disability Index scores improved from 46% to 16%, with an associated global rating of change scale score of +7 ("a very great deal better").

DISCUSSION

This case report describes the immediate and short-term clinical outcomes for a patient presenting with symptoms of neck pain and headache following anterior cervical discectomy and fusion surgical intervention. Clinical rationale and patient preference aided the decision to incorporate thoracic spine thrust manipulation as a treatment for this patient. Level of Evidence Therapy, level 4.

Cardiovascular disease is increased prior to onset of rheumatoid arthritis but not osteoarthritis: the population-based Nord-Trøndelag health study (HUNT)

Introduction

Patients with rheumatoid arthritis (RA) have increased risk of cardiovascular (CV) events. We sought to test the hypothesis that due to increased inflammation, CV disease and risk factors are associated with increased risk of future RA development.

Methods

The population-based Nord-Trøndelag health surveys (HUNT) were conducted among the entire adult population of Nord-Trøndelag, Norway. All inhabitants 20 years or older were invited, and information was collected through comprehensive questionnaires, a clinical examination, and blood samples. In a cohort design, data from HUNT2 (1995–1997, baseline) and HUNT3 (2006–2008, follow-up) were obtained to study participants with RA (n = 786) or osteoarthritis (n = 3,586) at HUNT3 alone, in comparison with individuals without RA or osteoarthritis at both times (n = 33,567).

Results

Female gender, age, smoking, body mass index, and history of previous CV disease were associated with self-reported incident RA (previous CV disease: odds ratio 1.52 (95% confidence interval 1.11-2.07). The findings regarding previous CV disease were confirmed in sensitivity analyses excluding participants with psoriasis (odds ratio (OR) 1.70 (1.23-2.36)) or restricting the analysis to cases with a hospital diagnosis of RA (OR 1.90 (1.10-3.27)) or carriers of the shared epitope (OR 1.76 (1.13-2.74)). History of previous CV disease was not associated with increased risk of osteoarthritis (OR 1.04 (0.86-1.27)).

Conclusion

A history of previous CV disease was associated with increased risk of incident RA but not osteoarthritis.

Osteoarthritis of the hand I: aetiology and pathogenesis, risk factors, investigation and diagnosis

Objective

Osteoarthritis (OA) of the hand can be a debilitating condition that hinders an individual's quality of life. With multiple joints within the hand that are commonly affected OA, an individual's ability to use their hand in everyday movements become more limited. The article aims to review literature on the aetiology and pathogenesis of OA, risk factors, characteristics of hand OA and the steps of diagnosis.

Key findings

The aetiology and pathogenesis of OA, in particular hand OA, is not fully understood. However, it is known that several factors play a role. Environmental factors, such as stress from mechanical loading, especially to vulnerable joints predispose individuals to developing OA. Extracellular matrix changes in protein levels have also been noted in individuals with OA. Linked to hand OA development are boney enlargements (Herbeden's and Bouchard's nodes). Several risk factors for OA include: age, obesity, gender, smoking, genetics, diet and occupation. Various diagnostic methods include a combination of using radiographic methods, clinical presentation, a number of developed measurements and scales.

Summary

With OA having several risk factors and various causes and contributing elements, it is important to elucidate the pathogenesis of OA and determine exactly how risk factors play a role in its development. Because of the contributions from several elements, diagnosis is best when it uses multiple methods. In turn, understanding OA and making better diagnoses could lead to improved management of the condition through both pharmacological and non-pharmacological interventions.

Chondrogenic potential of stem cells derived from adipose tissue: a powerful pharmacological tool

Chondrogenesis has been widely investigated in vitro using bone marrow-derived mesenchymal stromal cells (BM-MSCs) or primary chondrocytes. However, their use raises some issues partially circumvented by the availability of Adipose tissue-derived MSCs. Herein; we characterized the chondrogenic potential of human Multipotent Adipose-Derived Stem (hMADS) cells, and their potential use as pharmacological tool. hMADS cells are able to synthesize matrix proteins including COMP, Aggrecan and type II Collagen. Furthermore, hMADS cells express BMP receptors in a similar manner to BM-MSC, and BMP6 treatment of differentiated cells prevents expression of the hypertrophic marker type X Collagen. We tested whether IL-1β and nicotine could impact chondrocyte differentiation. As expected, IL-1β induced ADAMTS-4 gene expression and modulated negatively chondrogenesis while these effects were reverted in the presence of the IL-1 receptor antagonist. Nicotine, at concentrations similar to those observed in blood of smokers, exhibited a dose dependent increase of Aggrecan expression, suggesting an unexpected protective effect of the drug under these conditions. Therefore, hMADS cells represent a valuable tool for the analysis of in vitro chondrocyte differentiation and to screen for potentially interesting pharmacological drugs.

Quadriceps muscle strength and its relationship to radiographic knee osteoarthritis in Japanese elderly

BACKGROUND

Knee osteoarthritis (OA) is a multifactorial disease and strongly affected by mechanical factors. The aims of the present study were to assess validity and reliability of a new muscle strength measuring device, the Quadriceps Training Machine (QTM) and evaluate the relationship between quadriceps strength measured by QTM and radiographic knee OA by epidemiological survey.

METHODS

The isometric knee extension muscle strength of QTM was compared with BIODEX in 24 healthy adults. Then, the relationship between radiographic knee OA and quadriceps strength using QTM was investigated with 2,032 knees in 1,016 subjects by an epidemiological survey (Matsudai Knee Osteoarthritis Survey).

RESULTS

Significant correlation was observed between QTM and BIODEX (r = 0.69, 0.82). In the Matsudai Knee Osteoarthritis Survey, the prevalence of radiographic OA (grade II or higher upon Kellgren-Lawrence classification) was: 13, 36.9, 67.8, and 86.5 %, regarding women in their fifties, sixties, seventies, and eighties, respectively, and was 1.7, 13.4, 33.5, and 66.2 % regarding men, respectively. Quadriceps muscle strength declined following 50 years of age, and significant decline was observed in the their sixties and seventies. Quadriceps muscle strength of the OA group (grades II, III and IV) was significantly declined compared with that of the Non-OA group (grade-0 and I). Furthermore, the tendency of the muscle strength level to decline with the progression of knee OA grade was particularly observed between grade 0 and grade I in both men and women and between grade I and grade II in men.

CONCLUSION

The relationship between radiographic knee OA and quadriceps strength was quantitatively evaluated by an epidemiological survey, and we found a correlation between knee OA and the decline in quadriceps strength. Furthermore, it was suggested that the decline in quadriceps muscle strength may be more strongly related to the incidence of knee OA than to its progression.

The musculoskeletal effects of cigarette smoking

➤ Cigarette smoking decreases bone mineral density and increases the risk of sustaining a fracture or tendon injury, with partial reversibility of these risks with long-term cessation of smoking. ➤ Cigarette smoking increases the risk for perioperative complications, nonunion and delayed union of fractures, infection, and soft-tissue and wound-healing complications. ➤ Brief preoperative cessation of smoking may mitigate these perioperative risks. ➤ Informed-consent discussions should include notification of the higher risk of perioperative complications with cigarette smoking and the benefits of temporary cessation of smoking.

The natural history of degeneration of the lumbar and cervical spines: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To determine the population risk of radiographical degeneration in the lumbar and cervical spine as well as the risk of adjacent segment pathology (ASP) among patients who receive and do not receive (but were eligible for) fusion for lumbar or cervical degeneration.

SUMMARY OF BACKGROUND DATA

The etiology of ASP remains unclear. It has been suggested that ASP results because of a biomechanical stress transfer from the fusion. It has also been suggested that ASP is a continuation of natural arthritic disease. We sought to examine the literature and compare the rates of spinal degeneration without fusion and the rates of adjacent segment degeneration. Similarities or differences may yield insight into the etiology of ASP.

METHODS

A systematic review of the English language literature was undertaken for articles published between 1990 and March 15, 2012. Electronic databases and reference lists of key articles were searched to identify articles reporting prevalence and/or incidence of radiographical spinal degeneration (de novo degeneration) or radiographical adjacent segment pathology (RASP) (degeneration after fusion). Two independent reviewers assessed the level of evidence and the overall quality of the literature using the Grades of Recommendation Assessment, Development and Evaluation criteria. Disagreements were resolved by consensus.

RESULTS

We identified 15 studies from our search strategy that met the inclusion criteria from a total of 235 possible studies. Various definitions of radiographical spinal degeneration were used across the studies. For the population risk of radiographical lumbar and cervical spine degeneration, the cumulative incidence ranged from 12.7% to 51.5% during a 5- to 25-year period across 3 studies. One study of the cervical spine reported that there was a baseline prevalence of disc degeneration of 21.7% and, in their follow-up study, reported that 47.9% of individuals had evidence of progression of degeneration during a mean 5.8-year follow-up. The rate of progression per 100 person-years showed an age- and sex-specific trend, with females progressing at a faster rate than males through the 50s, males progressing faster than females during the 60s and 70s, with rates becoming identical in the 80s. Regarding age-specific risk, the prevalence of lumbar degeneration increased with age across 2 studies. For RASP following fusion, the cumulative incidence ranged from 6.3% to 44.4% during 6 to 12.6 years of follow-up across the 7 studies; the risk of cervical RASP was higher than that of lumbar despite the shorter mean follow-up periods.

CONCLUSION

RASP may occur at a higher rate than natural history and suggests that another factor (such as biomechanical effect of fusion) may accelerate pathologic changes.

CONSENSUS STATEMENT

ASP may occur at a higher rate than natural spinal degeneration and suggests that another factor (such as biomechanical effect of fusion) may accelerate pathologic changes. Strength of Statement: Weak.

Nicotine promotes proliferation and collagen synthesis of chondrocytes isolated from normal human and osteoarthritis patients

The aims of the study were to show the direct effect of nicotine with different concentrations (0, 25, 50, and 100 ng/ml) on chondrocytes isolated from normal human and osteoarthritis patients, respectively. Microscopic observation was performed during the culture with an inverted microscope. Methyl thiazolyl tetrazolium (MTT) assay method was adopted to observe the influence of nicotine on the proliferation of chondrocytes, and real-time PCR and ELISA were used to assay the mRNA and protein expression of type II collagen and aggrecan, respectively. We discovered that the OA chondrocytes were similar to fibroblasts in shape and grow slower than normal chondrocytes. The proliferation of the two kinds of chondrocytes was increased in a concentration-dependent manner and in a time-dependent manner (P<0.05). Also, we found that the mRNA level of type II collagen were upregulated under 25-100 ng/ml nicotine doses both in the two kinds of chondrocytes compared with control. The expression of protein levels of type II collagen were synthesized in line with the increase in mRNA. No effect was observed on aggrecan synthesis with any nicotine dose. We concluded that nicotine has the same effect on both chondrocytes, obtained either from osteoarthritis patients or from normal human, and the positive effect of smoking in OA may relate to the alteration in metabolism of chondrocytes.

Prevalence and associated factors of knee osteoarthritis in a community-based population in Heilongjiang, Northeast China

Few data exist concerning the prevalence of knee OA and associated factors in Northeast China. This study was undertaken to estimate the prevalence of radiographic and symptomatic knee OA among community residents and to elucidate relevant risk factors. Unmatched case-control study was adopted to study risk factors of knee OA. Radiographic OA was evaluated according to the Kellgren and Lawrence grading scheme. Statistical analyses included tests and logistic model regressions. A total of 1,196 people aged 40-84 years participated in the community-based health survey in Northeast China in 2005. Survey participants completed an interviewer-based questionnaire. The standardized prevalence of symptomatic knee OA was 16.05% and it was significantly higher in women than in men (19.87% vs. 11.91%, = 13.76, P < 0.001). There was also an increased tendency with age in both sex (men: x (2) = 29.67, P (trend) < 0.001; women: x (2) = 40.26, P (trend) < 0.001). The prevalence of symptomatic knee OA was significantly higher than that in Beijing and Shantou, while lower than that in Wuchuan county of inner Mongolia with nonsignificant difference. Logistic regressions revealed that age, sex, BMI, and work status might be risk factors for knee OA in urban residents, whereas age, BMI, and smoking habits might be risk factors in rural dwellers. Symptomatic knee OA is extremely common with preponderance for elderly women and constitutes a major public health problem. The findings will be useful to guide the distribution of future health care resources and preventive strategies.

A systematic review of radiographic definitions of foot osteoarthritis in population-based studies

OBJECTIVE

To identify the methods used in population-based epidemiological studies to diagnose radiographic foot osteoarthritis (OA) and to estimate the population prevalence of radiographic foot OA.

METHOD

Electronic databases searched included Medline, Embase, CINAHL and Ageline (inception to May 2009). The search strategy combined search terms for radiography, OA, foot, and specific foot joints. Predetermined selection criteria were applied. Data extracted from each paper included: sample population, radiographic views taken, foot joints examined, scoring system used, definition of OA applied, reliability of radiographic scoring and prevalence of radiographic OA in the foot.

RESULTS

Titles and abstracts of 1035 papers were reviewed and full-texts of 21 papers were obtained. Fifteen papers met inclusion criteria and a further 12 papers were included after screening references. Radiographic views were frequently not specified (NS) but a combination of antero-posterior (AP) and lateral (Lat) views was most commonly reported. The first metatarsophalangeal (MTP) joint was the most commonly examined joint (n=20, 74%). Nineteen studies (70%) used the Kellgren and Lawrence (K&L) grading system, 95% of which defined OA as K&L grade> or =2. Estimates of the prevalence of radiographic first MTP joint OA (defined as K&L> or =2) in middle-aged to older adults ranged from 6.3 to 39%. Significant statistical heterogeneity prevented pooling of prevalence estimates.

CONCLUSION

There are comparatively few studies examining radiographic foot OA. Existing studies mainly focus on the first MTP joint and use the K&L grading system. Future studies are needed to quantify the prevalence of radiographic OA at the different joint complexes within the foot.

Site specific osteoarthritis and the index to ring finger length ratio

OBJECTIVE

To quantify the relationship between the index to ring finger length ratio second digit:fourth digit(2D:4D) and radiographic osteoarthritis (OA) of the knee.

METHODS

Data from the Clearwater Osteoarthritis Study (COS) were analyzed. We selected a random sample of 236 subjects with knee OA (Kellgren-Lawrence scores >or=2) and compared their finger length ratio pattern with a random sample of 242 controls. Finger length measurements were recorded from digitized hand radiographs. Subjects were classified into three groups: type 1 (index finger longer than ring finger), type 2 (fingers of equal length) and type 3 (index finger shorter than ring finger). Using a case-control design, we calculated odds ratios (OR).

RESULTS

The type 3 finger pattern was significantly associated with knee OA (OR 2.59, 95% confidence interval (CI) 1.54-4.37). Women demonstrated a stronger association of visual type 3 finger pattern and knee OA (OR 4.40, 95% CI 2.62-7.38) compared to men (OR 2.59, 95% CI 1.34-5.00).

CONCLUSIONS

The type 3 finger length pattern is associated, to a statistically significant degree, with OA of the knee. The type 3 finger length pattern (ring finger longer than index finger) appears to be an indicator of OA predisposition. Consideration of this pattern in clinical assessments may be an added aid as clinicians screen patients for OA risk.

The robust association between childhood physical abuse and osteoarthritis in adulthood: findings from a representative community sample

OBJECTIVE

Research suggests a role of early-life trauma in the development of arthritis. This study investigated the relationship between childhood physical abuse and osteoarthritis (OA) while controlling for age, sex, race, and socioeconomic status (SES), in addition to the following types of risk factors for OA: 1) concurrent childhood stressors, 2) adult health behaviors, and 3) depression.

METHODS

Data from the provinces of Manitoba and Saskatchewan were selected from the 2005 Canadian Community Health Survey (n = 13,093). Respondents with missing arthritis data or with arthritis types other than OA were excluded (n = 1,985). Of the 11,108 remaining respondents, 6.9% (n = 854) reported childhood physical abuse by someone close to them, and 10.1% (n = 1,452) reported that they had been diagnosed with OA by a health professional. The regional-level response rate was 84%.

RESULTS

When adjusting for all 3 types of risk factors, a significant association between childhood physical abuse and OA was found (odds ratio [OR] 1.56, 95% confidence interval [95% CI] 1.21-2.00). In contrast, when adjusting for age, sex, race, and SES only, the OR was 1.99 (95% CI 1.57-2.52).

CONCLUSION

The association between childhood physical abuse and OA remained significant, even after controlling for many risk factors that may mediate the relationship. Further research is needed to investigate potential pathways through which arthritis develops as a consequence of childhood physical abuse.

Risk factors for onset of osteoarthritis of the knee in older adults: a systematic review and meta-analysis

OBJECTIVE

Knee osteoarthritis (OA) is common in older adults. Determination of risk factors for onset of knee OA may help in its prevention. The objective of this systematic review, and meta-analysis, was to determine the current evidence on risk factors for knee OA.

DESIGN

A systematic literature search was carried out for cohort and case-control studies evaluating the association of demographic, comorbid, and other patient-determined factors with onset of knee OA. A scoring tool was developed to assess the quality of studies. Heterogeneity of studies was examined. Where possible studies were pooled to give an overall estimate of the association of factors with onset of knee OA.

RESULTS

Of the 2233 studies screened, 85 were eventually included in the review. Study quality tended to be moderate. The main factors consistently associated with knee OA were obesity (pooled OR 2.63, 95% CI 2.28-3.05), previous knee trauma (pooled OR 3.86, 95% CI 2.61-5.70), hand OA (pooled OR 1.49, 95% CI 1.05-2.10), female gender (pooled OR 1.84 95% CI 1.32-2.55) and older age. Smoking appeared to have a moderate protective effect, however this was not evident once the analysis was restricted to cohort studies only.

CONCLUSIONS

Whilst certain factors have been extensively reviewed (for example, body mass index), more longitudinal studies are needed to investigate the association of physical occupational and other patient-determined factors with future knee OA. The quality of such studies also needs to be improved. However, there are identifiable factors which can be targeted for prevention of disabling knee pain.

Smoking is associated with increased cartilage loss and persistence of bone marrow lesions over 2 years in community-based individuals

OBJECTIVE

To determine whether smoking is related to change in tibial and patella cartilage, and the development or persistence of bone marrow lesions (BMLs) over 2 years in a cohort of middle-aged adults.

METHODS

Two hundred and seventy-one adult subjects recruited from the Melbourne Collaborative Cohort Study underwent an MRI of their dominant knee at baseline and approximately 2 years later. Cartilage volume and BMLs were determined for both time points. At baseline, subjects also completed a questionnaire about current and past cigarette smoking.

RESULTS

Being a 'smoker' (former or current) was associated with increased annual loss of medial but not lateral or patella cartilage volume (medial: difference = 13.4 microl, P = 0.03; lateral difference = 4.86 microl, P = 0.45, patella difference = -2.57 microl, P = 0.79). A relationship between increasing pack-years smoked and increased medial cartilage volume loss was also observed (P = 0.04). Amongst people who had a BML at baseline, BMLs present in 'ever smokers' were 11.4 [95% confidence interval (CI) 1.54, 89.9; P = 0.02] times more likely to persist over 2 years than those present in 'never smokers'. In addition, the relationship between smoking and increased medial cartilage loss for subjects with a BML present at baseline was partially mediated by the persistence of the BMLs over 2 years.

CONCLUSION

This study contributes to the evidence of a detrimental effect of smoking on joint cartilage. Furthermore, it provides a possible mechanism that the association smoking shares with increased cartilage loss may be mediated via smoking impairing the ability for BMLs to resolve.

Smoking and nicotine exposure delay development of collagen-induced arthritis in mice

Introduction

Recent epidemiologic studies have implicated smoking as an environmental risk factor for the development of rheumatoid arthritis (RA). The aim of the present study is the evaluation of the role of cigarette smoke (CS) in the pathogenesis of collagen-induced arthritis in mice.

Methods

DBA/1 mice exposed to CS for 16 weeks (n = 25) and mice exposed to nicotine in drinking water (n = 10) were immunized with collagen type II (CII). Severity of arthritis was evaluated clinically and morphologically and compared with control mice (n = 35). Intensity of inflammation was evaluated by serum IL-6 and TNF-α levels. Additionally, antibody response to CII (anti-CII) and citrullinated peptides (aCCP) was measured.

Results

Clinical evaluation of arthritis showed a delayed onset of arthritis in CS-exposed mice compared with non-smoking controls (P < 0.05). Histologic index and weight changes were comparable between the groups; however, smoking mice presented less weight loss during the acute phase of the disease and gained weight significantly faster in the recovery phase (P < 0.05). Similar results were obtained in the mice exposed to nicotine. Nicotine also showed a direct anti-inflammatory effect diminishing IL-6 production by stimulated splenocytes in vitro (P < 0.001). Additionally, smoking mice had lower levels of aCCP and anti-CII antibodies compared with non-smoking (P < 0.05).

Conclusions

Neither smoking nor nicotine exposure aggravates development of CII-induced arthritis in mouse model. Moreover, CS exposure was associated with a lower level of anti-CII antibodies, providing a possible explanation for a delay of arthritis onset in this group.

Association of regional racial/cultural context and socioeconomic status with arthritis in the population: a multilevel analysis

OBJECTIVE

To examine the extent to which differences in individual- and regional-level socioeconomic status and racial/cultural origin account for geographic variations in the prevalence of self-reported arthritis, and to determine whether regional characteristics modify the effect of individual characteristics associated with reporting arthritis.

METHODS

Analyses were based on the 2000-2001 Canadian Community Health Survey (>15 years, n = 127,513). Arthritis was self-reported as a long-term condition diagnosed by a health professional. A 2-level logistic regression model was used to identify predictors of reporting arthritis. Individual-level variables included age, sex, income, education, immigration status, racial/cultural origin, smoking, physical activity, and body mass index. Regional-level variables included the proportion of low-income families, low education, unemployment, recent immigrants, Aboriginals, and Asians.

RESULTS

At the individual level, age, sex, low income, low education, Aboriginal origin, current smoking, and overweight/obesity were positively associated with reporting arthritis; recent immigration and Asian origin were negatively associated with reporting arthritis. At the regional level, percentages of low-income families and the Aboriginal population were independently associated with reporting arthritis. Regional income and racial/cultural origin moderated the effects of individual income and racial/cultural origin; low-income individuals residing in regions with a higher proportion of low-income families reported arthritis more than low-income individuals living in better-income regions.

CONCLUSION

Both individual and regional factors were found to contribute to variations in the prevalence of arthritis, although significant unexplained variation remained. Further research is required to better understand the mechanisms that underlie these regional effects and to identify other contributing factors to the remaining variation.

Two-year prospective longitudinal study exploring the factors associated with change in femoral cartilage volume in a cohort largely without knee radiographic osteoarthritis

OBJECTIVE

To identify factors associated with change in femoral cartilage volume over 2 years in a cohort largely without knee radiographic osteoarthritis.

METHODS

A total of 252 subjects (mean 45 years, range 28-60) were used for this study. T1-weighted fat saturation magnetic resonance imaging was performed at baseline and approximately 2 years later. Knee femoral condyle cartilage volume, femoral cartilage defect (0-4 scale) and tibial bone size were determined.

RESULTS

The total femoral cartilage volume loss was 6.3% for the 2.3-year period. Factors associated with this annual change were female gender (females vs males: -1.69%, P<0.01), age (over vs under 40 years: -0.96%, P=0.01), smoking (beta: -0.04% per pack-years, P<0.01), as well as lower limb muscle strength (r: +0.32, P<0.01) and its change (beta: +0.34% per quartile, P<0.05). Structural factors associated with change included baseline femoral cartilage volume (beta: -0.36% per ml, P<0.01), femoral cartilage defects (beta: +1.07% per grade, P<0.01), tibial bone area (beta: +0.13% per cm(2), P<0.05), lateral osteophytes (beta: -1.91% per grade, P<0.01) and change in femoral cartilage defects (beta: -0.8% per grade, P<0.001).

CONCLUSIONS

This study provides evidence confirming that significant risk factors are associated with femoral cartilage loss and these include gender (female), age, smoking, and severity of lower limb muscle weakness. It also supports the hypothesis that femoral cartilage swelling reflected by an increased baseline cartilage volume could be a predictor of disease progression. Our findings also provide interesting clues to implement preventive measures that can possibly prevent or reduce knee cartilage loss.

A systematic search and narrative review of radiographic definitions of hand osteoarthritis in population-based studies

OBJECTIVE

Currently there is no agreed "gold standard" definition of radiographic hand osteoarthritis (RHOA) for use in epidemiological studies. We therefore undertook a systematic search and narrative review of community-based epidemiological studies of hand osteoarthritis (OA) to identify (1) grading systems used, (2) definitions of radiographic OA for individual joints and (3) definitions of overall RHOA.

METHODS

The following electronic databases were searched: Medline, Embase, Science Citation Index and Ageline (inception to Dec 2006). The search strategy combined terms for "hand" and specific joint sites, OA and radiography. Inclusion and exclusion criteria were applied. Data were extracted from each paper covering: hand joints studied, grading system used, definitions applied for OA at individual joints and overall RHOA.

RESULTS

Titles and abstracts of 829 publications were reviewed and the full texts of 399 papers were obtained. One hundred fifty-two met the inclusion criteria and 24 additional papers identified from screening references. Kellgren and Lawrence (K&L) was the most frequently applied grading system used in 80% (n=141) of studies. In 71 studies defining OA at the individual joint level 69 (97%) used a definition of K&L grade > or = 2. Only 53 publications defined overall RHOA, using 21 different definitions based on five grading systems.

CONCLUSION

The K&L scheme remains the most frequently used grading system. There is a consistency in defining OA in a single hand joint as K&L grade > or = 2. However, there are substantial variations in the definitions of overall RHOA in epidemiological studies.

Smoking interacts with family history with regard to change in knee cartilage volume and cartilage defect development

OBJECTIVE

To describe the effects of smoking on change in knee cartilage volume and increases in knee cartilage defects, and to test for interaction between smoking and family history of osteoarthritis (OA).

METHODS

Subjects with at least 1 parent having severe primary knee OA (offspring) and randomly selected controls without this history (a total of 325 subjects with a mean age of 45 years) were measured at baseline and 2.3 years later. Knee cartilage volume and defect score (on a 0-4 scale) were determined using T1-weighted fat-saturated magnetic resonance imaging. Smoking status and duration and number of cigarettes were recorded by questionnaire.

RESULTS

In offspring, smoking was associated with annual change in medial and lateral tibial cartilage volume (beta = -2.20% and beta = -1.45%, respectively, for current smokers versus former smokers and those who had never smoked; beta = -0.07%/pack-year at both tibial sites, for smoking severity) in multivariate analysis. Smoking was also associated with increases (change >or=1) in medial and lateral tibiofemoral cartilage defect scores (odds ratio [OR] 4.91 and OR 2.98, respectively, for current smokers versus those who had never smoked; OR 9.90 and OR 12.98, respectively, for heavy smoking [total of >20 pack-years] versus never smoking) (all P < 0.05). In contrast, smoking was not associated with any of the above in controls except for change in lateral tibial cartilage volume. There was significant interaction between smoking and offspring-control status for change in medial tibial cartilage volume (P = 0.047) and increases in medial (P = 0.03) and lateral (P = 0.049) tibiofemoral cartilage defects.

CONCLUSION

Smoking leads to knee cartilage loss and defect development primarily in individuals with a family history of knee OA. This provides evidence for a gene-environment interaction in the etiology of knee OA.