Marlene Fransen

The global burden of hip and knee osteoarthritis: estimates from the Global Burden of Disease 2010 study

Objective To estimate the global burden of hip and knee osteoarthritis (OA) as part of the Global Burden of Disease 2010 study and to explore how the burden of hip and knee OA compares with other conditions. Methods Systematic reviews were conducted to source age-specific and sex-specific epidemiological data for hip and knee OA prevalence, incidence and mortality risk. The prevalence and incidence of symptomatic, radiographic and self-reported hip or knee OA were included. Three levels of severity were defined to derive disability weights (DWs) and severity distribution (proportion with mild, moderate and severe OA). The prevalence by country and region was multiplied by the severity distribution and the appropriate disability weight to calculate years of life lived with disability (YLDs). As there are no deaths directly attributed to OA, YLDs equate disability-adjusted life years (DALYs). Results Globally, of the 291 conditions, hip and knee OA was ranked as the 11th highest contributor to global disability and 38th highest in DALYs. The global age-standardised prevalence of knee OA was 3.8% (95% uncertainty interval (UI) 3.6% to 4.1%) and hip OA was 0.85% (95% UI 0.74% to 1.02%), with no discernible change from 1990 to 2010. Prevalence was higher in females than males. YLDs for hip and knee OA increased from 10.5 million in 1990 (0.42% of total DALYs) to 17.1 million in 2010 (0.69% of total DALYs). Conclusions Hip and knee OA is one of the leading causes of global disability. Methodological issues within this study make it highly likely that the real burden of OA has been underestimated. With the aging and increasing obesity of the worlds population, health professions need to prepare for a large increase in the demand for health services to treat hip and knee OA.

Risk factors associated with the transition from acute to chronic occupational back pain

Study Design. A prospective cohort study was conducted on workers claiming earnings-related compensation for low back pain. Information obtained at the time of the initial claim was linked to compensation status (still claiming or not claiming) 3 months later. Objective. To identify individual, psychosocial, and workplace risk factors associated with the transition from acute to chronic occupational back pain. Summary of Background Data. Despite the magnitude of the economic and social costs associated with chronic occupational back pain, few prospective studies have investigated risk factors identifiable in the acute stage. Methods. At the time of the initial compensation claim, a self-administered questionnaire was used to gather information on a wide range of risk factors. Then 3 months later, chronicity was determined from claimants’ computerized records. Results. The findings showed that 3 months after the initial assessment, 204 of the recruited 854 claimants (23.9%) still were receiving compensation payments. A combined multiple regression model of individual, psychosocial, and workplace risk factors demonstrated that severe leg pain (odds ratio [OR], 1.9), obesity (OR, 1.7), all three Oswestry Disability Index categories above minimal disability (OR, 3.1–4), a General Health Questionnaire score of at least 6 (OR, 1.9), unavailability of light duties on return to work (OR, 1.7), and a job requirement of lifting for three fourths of the day or more all were significant, independent determinants of chronicity (P < 0.05). Conclusions. Simple self-report measures of individual, psychosocial, and workplace factors administered when earnings-related compensation for back pain is claimed initially can identify individuals with increased odds for development of chronic occupational disability.

The impact of obesity on the musculoskeletal system

Obesity is associated with a range of disabling musculoskeletal conditions in adults. As the prevalence of obesity increases, the societal burden of these chronic musculosketelal conditions, in terms of disability, health-related quality of life, and health-care costs, also increases. Research exploring the nature and strength of the associations between obesity and musculoskeletal conditions is accumulating, providing a better understanding of underlying mechanisms. Weight reduction is important in ameliorating some of the manifestations of musculoskeletal disease and improving function.

Land-based exercise for osteoarthritis of the knee: a metaanalysis of randomized controlled trials.

Objective. To determine if clinical guidelines recommending therapeutic exercise for people with knee osteoarthritis (OA) are supported by rigorous scientific evidence. To explore whether the magnitude of treatment benefit reported in randomized controlled trials (RCT) is associated with exercise dosage or study methodology. Methods. We conducted a metaanalysis of RCT comparing some form of land-based therapeutic exercise with a nonexercise group using pain and self-reported physical function outcomes. Results. The 32 included studies provided data on almost 3800 participants. Metaanalysis revealed a beneficial treatment effect: standardized mean difference (SMD) 0.40 [95% confidence interval (CI) 0.30 to 0.50] for knee pain; SMD 0.37 (95% CI 0.25 to 0.49) for physical function. While the pooled beneficial effects of the 9 RCT evaluating exercise programs providing fewer than 12 direct supervision occasions or the 9 RCT judged to have a low risk of bias remained significant and clinically relevant, the magnitude of treatment benefit pooled from these RCT was significantly smaller than the comparator group (12 or more supervision occasions, moderate to high risk of bias, respectively). The mode of treatment delivery (individual treatments, exercise classes, home program) was not significantly associated with the magnitude of treatment benefit. Conclusion. There is evidence that land-based therapeutic exercise has at least short-term benefit in terms of reduced knee pain and physical disability for people with knee OA. The magnitude of the treatment effect was significantly associated with the number of direct supervision occasions provided and study methodology (assessor blinding, adequate allocation concealment).

The epidemiology of osteoarthritis in Asia

Worldwide, osteoarthritis (OA) is estimated to be the fourth leading cause of disability. Most of this disability burden is attributable to the involvement of the hips or the knees. OA is strongly associated with ageing and the Asian region is ageing rapidly. Further, OA has been associated with heavy physical occupational activity, a required livelihood for many people living in rural communities in developing countries. Unfortunately, joint replacement surgery, an effective intervention for people with severe OA involving the hips or knees, is inaccessible to most people in these regions. On the other hand, obesity, another major risk factor, may be less prevalent, although it is on the increase. Determining region‐specific OA prevalence and risk factor profiles will provide important information for planning future cost‐effective preventive strategies and health care services. An update of what is currently known about the prevalence of hip and knee OA from population‐based studies conducted in the Asian region is presented in this review. Many of the recent studies have conducted comparisons between urban and rural areas and poor and affluent communities. The results of Asian‐based studies evaluating risk factors from population‐based cohorts or case–control studies, and the current evidence on OA morbidity burden in Asia is also outlined.

Excess Mortality or Institutionalization After Hip Fracture: Men Are at Greater Risk Than Women

To assess 2‐year excess mortality or institutionalization risk associated with hip fracture in community‐dwelling people aged 60 and over.

Weight loss in obese people has structure-modifying effects on medial but not on lateral knee articular cartilage

Background Obesity is an important risk factor for knee osteoarthritis (OA), Weight loss can reduce the symptoms of knee OA. No prospective studies assessing the impact of weight loss on knee cartilage structure and composition have been performed. Objectives To assess the impact of weight loss on knee cartilage thickness and composition. Methods 111 obese adults were recruited from either laparoscopic adjustable gastric banding or exercise and diet weight loss programmes from two tertiary centres. MRI was performed at baseline and 12-month follow-up to assess cartilage thickness. 78 eligible subjects also underwent delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), an estimate of proteoglycan content. The associations between cartilage outcomes (cartilage thickness and dGEMRIC index) and weight loss were adjusted for age, gender, body mass index (BMI) and presence of clinical knee OA. Results Mean age was 51.7±11.8 years and mean BMI was 36.6±5.8 kg/m2; 32% had clinical knee OA. Mean weight loss was 9.3±11.9%. Percentage weight loss was negatively associated with cartilage thickness loss in the medial femoral compartment in multiple regression analysis (β=0.006, r2=0.19, p=0.029). This association was not detected in the lateral compartment (r2=0.12, p=0.745). Percentage weight loss was associated with an increase in medial dGEMRIC in multiple regression analysis (β=3.9, r2=0.26; p=0.008) but not the lateral compartment (r2=0.14, p=0.34). For every 10% weight loss there was a gain in the medial dGEMRIC index of 39 ms (r2=0.28; p=0.014). The lowest weight loss cut-off associated with reduced medial femoral cartilage thickness loss and improved medial dGEMRIC index was 7%. Conclusions Weight loss is associated with improvements in the quality (increased proteoglycan content) and quantity (reduced cartilage thickness losses) of medial articular cartilage. This was not observed in the lateral compartment. This could ultimately lead to a reduced need for total joint replacements and is thus a finding with important public health implications.

Exercise for osteoarthritis of the knee: a Cochrane systematic review

Objective To determine whether land-based therapeutic exercise is beneficial for people with knee osteoarthritis (OA) in terms of reduced joint pain or improved physical function and quality of life. Methods Five electronic databases were searched, up until May 2013. Randomised clinical trials comparing some form of land-based therapeutic exercise with a non-exercise control were selected. Three teams of two review authors independently extracted data and assessed risk of bias for each study. Standardised mean differences immediately after treatment and 2–6 months after cessation of formal treatment were separately pooled using a random effects model. Results In total, 54 studies were identified. Overall, 19 (35%) studies reported adequate random sequence generation, allocation concealment and adequately accounted for incomplete outcome data. However, research results may be vulnerable to selection, attrition and detection bias. Pooled results from 44 trials indicated that exercise significantly reduced pain (12 points/100; 95% CI 10 to 15) and improved physical function (10 points/100; 95% CI 8 to 13) to a moderate degree immediately after treatment, while evidence from 13 studies revealed that exercise significantly improved quality of life immediately after treatment with small effect (4 points/100; 95% CI 2 to 5). In addition, 12 studies provided 2-month to 6-month post-treatment sustainability data which showed significantly reduced knee pain (6 points/100; 95% CI 3 to 9) and 10 studies which showed improved physical function (3 points/100; 95% CI 1 to 5). Conclusions Among people with knee osteoarthritis, land-based therapeutic exercise provides short-term benefit that is sustained for at least 2–6 months after cessation of formal treatment.

Glucosamine and chondroitin for knee osteoarthritis: a double-blind randomised placebo-controlled clinical trial evaluating single and combination regimens

Objective To determine if the dietary supplements, glucosamine and/or chondroitin, result in reduced joint space narrowing (JSN) and pain among people with symptomatic knee osteoarthritis. Methods A double-blind randomised placebo-controlled clinical trial with 2-year follow-up. 605 participants, aged 45–75 years, reporting chronic knee pain and with evidence of medial tibio-femoral compartment narrowing (but retaining >2 mm medial joint space width) were randomised to once daily: glucosamine sulfate 1500 mg (n=152), chondroitin sulfate 800 mg (n=151), both dietary supplements (n=151) or matching placebo capsules (n=151). JSN (mm) over 2 years was measured from digitised knee radiographs. Maximum knee pain (0–10) was self-reported in a participant diary for 7 days every 2 months over 1 year. Results After adjusting for factors associated with structural disease progression (gender, body mass index (BMI), baseline structural disease severity and Heberdens nodes), allocation to the dietary supplement combination (glucosamine–chondroitin) resulted in a statistically significant (p=0.046) reduction of 2-year JSN compared to placebo: mean difference 0.10 mm (95% CI 0.002 mm to 0.20 mm); no significant structural effect for the single treatment allocations was detected. All four allocation groups demonstrated reduced knee pain over the first year, but no significant between-group differences (p=0.93) were detected. 34 (6%) participants reported possibly-related adverse medical events over the 2-year follow-up period. Conclusions Allocation to the glucosamine–chondroitin combination resulted in a statistically significant reduction in JSN at 2 years. While all allocation groups demonstrated reduced knee pain over the study period, none of the treatment allocation groups demonstrated significant symptomatic benefit above placebo. Trial Registration ClinicalTrials.gov identifier: NCT00513422; http://www.clinicaltrials.gov

Influence of BMI on Health‐related Quality of Life: Comparison Between an Obese Adult Cohort and Age‐matched Population Norms

The aim of this study was to determine health‐related quality of life and fatigue measures in obese subjects and to compare scores with age‐ and gender‐matched population norms. A total of 163 obese subjects were recruited from laparoscopic‐adjustable gastric banding or exercise and diet weight loss programs between March 2006 and December 2007. All subjects completed the Medical Outcomes Study Short Form 36 (SF‐36), Assessment of Quality of Life (AQoL), and Multidimensional Assessment of Fatigue (MAF) questionnaires. One‐sample t‐tests were used to compare transformed scores with age‐ and gender‐matched population norms and controls. Obese subjects have significantly lower SF‐36 physical and emotional component scores, significantly lower AQoL utility scores and significantly higher fatigue scores compared to age‐matched population norms. Within the study cohort, the SF‐36 physical functioning, role physical and bodily pain scores, and AQoL utility index were even lower in subjects with clinical knee osteoarthritis (OA). However, obese individuals without OA still had significantly lower scores compared to population norms. Obesity is associated with impaired health‐related quality of life and disability as measured by the SF‐36, AQoL, and fatigue score (MAF) compared to matched population norms.