Osteoarthritis research priorities: a report from a EULAR ad hoc expert committee

Prevalence of knee osteoarthritis, risk factors, and quality of life: The Fifth Korean National Health And Nutrition Examination Survey

AIM

Although there have been regional population-based studies on the prevalence of knee osteoarthritis (KOA) and its risk factors in South Koreans, those studies in common had limited external validity. This study aims to estimate the national prevalence of KOA and its risk factors using a complex sampling design.

METHODS

This was a cross-sectional study including 9512 participants aged ≥ 50 years of The Fifth Korean National Health and Nutrition Examination Survey, who were selected using two-step stratified clustered equal-probability systematic sampling. Radiographic KOA (RKOA) was defined as a Kellgren-Lawrence grade of ≥ 2. Symptoms of KOA were evaluated through a health interview. Obesity was defined as a body mass index ≥ 27.5 kg/m²_. Quality of life was measured by the Korean version of European Quality of Life Questionnaire (EQ-5D).

RESULTS

The prevalence of RKOA was 21.1% (95% CI: 19.6-22.8%) in men, and 43.8% (42.0-45.6%) in women. The prevalence of symptomatic RKOA (SRKOA) was 4.4% (3.8-5.2%) and 19.2% (17.9-20.6%) in men and women, respectively. The EQ-5D index was lower in participants with KOA. When plotted against mean age and prevalence of obesity, regions with a higher mean age and prevalence of obesity had higher prevalence of KOA, which was also observed at the individual level. The prevalence of SRKOA was 36.6% (29.7-44.1%) in women in Jeju province.

CONCLUSION

The prevalence of SRKOA in women reached 36.6% in high-risk groups accompanied by low quality of life. The results suggest that the disease burden of KOA is high in South Korea.

Severe radiographic knee osteoarthritis--does Kellgren and Lawrence grade 4 represent end stage disease?--the MOST study

OBJECTIVE

To determine what MRI-detectable osteoarthritis features that are not visualized on radiography demonstrate progression longitudinally in Kellgren and Lawrence (KL) grade 4 knees.

METHODS

We studied subjects from the Multicenter Osteoarthritis Study who had KL grade 4 knees at baseline and had baseline and 30-month MRI. Cartilage damage, bone marrow lesions (BMLs), meniscal damage, synovitis (signal changes in Hoffa fat pad), and effusion (fluid equivalent signal in the joint cavity) were semiquantitatively scored using the Whole Organ MRI Score (WORMS) system in five subregions of the medial and lateral tibiofemoral (TF) compartments. Analysis was performed for the compartment showing bone-on-bone appearance ("index") on radiograph and also for the other TF compartment of the same knee. Synovitis and effusion were assessed for the whole knee. Changes in scores at follow-up were noted for each feature. For cartilage and BML, within-grade changes were also recorded.

RESULTS

140 subjects (164 knees) were included (50% women, mean age 66.0 ± 8.6 years, mean BMI 30.4 ± 5.1 kg/m(2)). Longitudinally, 51 index compartments (34%) showed an increase in the sum of cartilage scores from all subregions. In the other compartment, 25% showed an increase in the sum score for cartilage damage. For BMLs in the index compartment, 50 knees (33%) showed an increase in maximum score and 32 (21%) showed a decrease. Meniscal status mostly remained stable. Effusion worsened in 36 knees (25%) and improved in 13 knees (9%). Synovitis worsened in 14 knees (10%) and improved in six knees (4%).

CONCLUSION

In KL grade 4 knees, MRI-detected cartilage loss and fluctuation of BMLs, effusion, and synovitis occurred frequently over a 30-month period.

Patient-reported outcomes in core domain sets for rheumatic diseases

Patient-reported outcomes (PROs) are abundant in rheumatology and their numbers continue to increase. But which of the available measures are most important? Core outcome sets-including groups of domains and instruments for measuring them-have been defined for many rheumatic diseases, with the aim that all these outcomes should be measured in every clinical trial. The subgroup of PROs included in these core sets is, therefore, undoubtedly important. This Review summarizes the PROs included in core outcome sets developed for use in clinical trials across a wide range of rheumatic diseases. Three PROs are commonly utilized across the majority of rheumatic conditions: pain, physical functioning and the patient global assessment of disease activity. However, additional research is needed to fully understand the role of the patient global assessment of disease activity, to distinguish specific domains within the broad concept of health-related quality of life, and to work towards consensus on the choice between generic and disease-specific instruments in various contexts.

Discrepancies in composition and biological effects of different formulations of chondroitin sulfate

Osteoarthritis is a common, progressive joint disease, and treatments generally aim for symptomatic improvement. However, SYmptomatic Slow-Acting Drugs in Osteoarthritis (SYSADOAs) not only reduce joint pain, but slow structural disease progression. One such agent is chondroitin sulfate—a complex, heterogeneous polysaccharide. It is extracted from various animal cartilages, thus has a wide range of molecular weights and different amounts and patterns of sulfation. Chondroitin sulfate has an excellent safety profile, and although various meta-analyses have concluded that it has a beneficial effect on symptoms and structure, others have concluded little or no benefit. This may be due, at least partly, to variations in the quality of the chondroitin sulfate used for a particular study. Chondroitin sulfate is available as pharmaceutical- and nutraceutical-grade products, and the latter have great variations in preparation, composition, purity and effects. Moreover, some products contain a negligible amount of chondroitin sulfate and among samples with reasonable amounts, in vitro testing showed widely varying effects. Of importance, although some showed anti-inflammatory effects, others demonstrated weak effects, and some instances were even pro-inflammatory. This could be related to contaminants, which depend on the origin, production and purification process. It is therefore vitally important that only pharmaceutical-grade chondroitin sulfate be used for treating osteoarthritis patients.

Non-surgical management of knee osteoarthritis: where are we now and where do we need to go?

After the successful treatment of inflammatory rheumatic diseases with targeted therapies, the greatest challenge in rheumatic diseases remains the treatment of the most common chronic joint disorder, osteoarthritis. Osteoarthritis (OA) commonly affects the knee, with an age-standardised and sex-standardised incidence of 240 per 100.000 person-years. With the aging of the population and rising obesity throughout the world, it is anticipated that the burden of OA will increase and become a major problem for health systems globally. Given this background, proper guidance on the management of OA is needed. This issue has been addressed over recent months in updated guidelines or recommendations detailing three treatment modalities: non-pharmacological, pharmacological and surgical. It should be noted, that OA is not a uniform disease entity. In some patients, progression of the disease seems to be driven by cartilage factors, in others by bone factors or by inflammatory factors. Ongoing research aims to identify potential biomarkers for these different forms of OA. Research is also underway into disease modifying OA drugs (DMOADs) that target different aspects of the disease, treatments for OA pain, and cell-based therapies.

Femoroacetabular impingement surgery: are we moving too fast and too far beyond the evidence?

Femoroacetabuler impingement (FAI) is becoming increasingly recognised as a potential pathological entity for individuals with hip pain. Surgery described to correct FAI has risen exponentially in the past 10 years with the use of hip arthroscopy. Unfortunately, the strength of evidence supporting both the examination and treatment of FAI does not appear to accommodate this exponential growth. In fact, the direction currently taken for FAI is similar to previously described paths of other orthopaedic and sports medicine pathologies (eg, shoulder impingement, knee meniscus tear) for which we have learned valuable lessons. The time has come for improved terminology, study design, and focus on delineation of successful treatment variables in the interest of those individuals with clinical indications of FAI so that we can appropriately address their needs.

Osteoarthritis: priorities for osteoarthritis research: much to be done

With a frustrating lack of progress in the development of treatments for osteoarthritis, EULAR has released recommendations to reorient research into this disease. These recommendations include focused attention on noncartilagenous tissues, the interaction of structures within the joint, the pathogenesis of osteoarthritic pain, new treatment strategies and early disease.