Lisa Bridgett

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.

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.

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

Changes in long jump take-off technique with increasing run-up speed.

Abstract The aim of this study was to determine the influence of run-up speed on take-off technique in the long jump. Seventy-one jumps by an elite male long jumper were recorded in the sagittal plane by a high-speed video camera. A wide range of run-up speeds was obtained using direct intervention to set the length of the athletes run-up. As the athletes run-up speed increased, the jump distance and take-off speed increased, the leg angle at touchdown remained almost unchanged, and the take-off angle and take-off duration steadily decreased. The predictions of two previously published mathematical models of the long jump take-off are in reasonable agreement with the experimental data.

Hip and knee pain: Role of occupational factors

Many people rely economically on occupations involving high loading of the hip or knee joints for lengthy periods, possibly placing them at increased risk of developing chronic pain in these joints. There is a growing body of evidence from large longitudinal cohort studies, case-control studies and population-based surveys that certain occupations, or having work involving considerable heavy lifting, kneeling or squatting, may be associated with increased risk of symptomatic hip or knee osteoarthritis and joint replacement surgery. Only a few studies have evaluated the effectiveness of specific workplace strategies to reduce this risk. Identifying modifiable workplace risk factors and implementing feasible and accessible preventative strategies will be of great public health significance in the next decade.

Post-Acute Rehabilitation After Total Knee Replacement: A Multicenter Randomized Clinical Trial Comparing Long-Term Outcomes

To evaluate the long‐term benefit of providing a post‐acute, outpatient group exercise program for patients following primary total knee replacement (TKR) surgery for osteoarthritis.

352 WORK DISABILITY AMONG PEOPLE WITH MILD TO MODERATE KNEE OSTEOARTHRITIS

open-ended free text question, which were coded into thematic groups. Ordered logistic regression modelling was used to look at the association between patients pre-operative expectations and baseline characteristics (age, sex, education, ASA status, K&L grade, obesity, medication use, WOMAC score, EQ5D score). The OMERACT-OARSI responder criteria were used to classify patients as improved/not improved 12-months after THR. Logistic regression modelling was used to explore whether pre-operative expectations predict response to THR, adjusting for baseline characteristics. Results: A greater number of recorded pre-operative expectations were associated with younger age, women, more education, lower ASA grade, obesity, greater medication use, and worse pre-operative pain and function (WOMAC score). Analyses identifying predictors of outcome, suggested that the more pre-operative expectations a patient had, the more likely they were to improve after surgery. Each individual expectation a patient had, was associated with a 26% increase in the probability of improvement (95%CI 1%-56%). Sensitivity analyses, using different methods to classify patients as responders to surgery, support this finding. Analyses within WOMAC subgroups suggest the association is strongest for stiffness and function. Other predictor variables were associated with improved patient outcomes. Educated people had greater improvement following surgery, as were those with worse baseline pain and function. Patients with less severe radiographic change had a better outcome. Patients with higher ASA grades were less likely to respond, as were obese patients. Age, sex and pre-operative medication use were not associated with outcome. Conclusions: This study demonstrates variability in patients’ pre-operative expectations of THR surgery. Patients with a larger number of pre-operative expectations are more likely to have a good clinically important outcome 12-months post-THR. This appears to be driven more by stiffness and function, rather than pain. The majority of patients described expectations regarding function which is likely an artefact of how the expectation question was worded, asking patients what they would be “able to do”. These findings have implications for informed patient-clinician decision-making. As unfulfilled expectations are related to patients reporting poor outcomes of surgery and lower levels of satisfaction, some have suggested surgeons should attempt to moderate patients hopes of surgery when discussing the likely outcomes of surgery given their individual characteristics. An alternative point of view is that the patients greater expectations contributed to outcome by acting as a psychological contextual factor, which ultimately influences pain and function post-op (unconditioned “placebo”). Further research should address these two different causes of action.

338 SCREENING, RECRUITMENT AND BASELINE CHARACTERISTICS OF THE LONG-TERM EVALUATION OF GLUCOSAMINE SULPHATE (LEGS) STUDY PARTICIPANTS

Clinical trials evaluating potential ’disease-modifying’ agents for osteoarthritis are required to demonstrate both symptomatic and structural benefit. Ideally, to reduce ceiling or floor effects, study participants are required to have at least moderate pain, yet retain sufficient tibiofemoral joint space to allow the measurement of narrowing over time. To describe study recruitment procedures and baseline demographics of people with symptomatic knee osteoarthritis participating in the Long-term Evaluation of Glucosamine Sulphate (LEGS) study (NCT00513422).