Development and prevention of knee osteoarthritis: The load of obesity

According to the World Health Organization, more than 150 million (± 2.5%) people suffer from osteoarthritis (OA ) worldwide. Above the age of 60 years, these figures even rise to 10% 2. In almost 30% of these cases, OA leads to moderate to severe disability. Thereby, it is the most common joint disease for the middle-aged and older population In the Netherlands, OA is estimated to affect more than 650.000 people. Annual health care costs associated with OA are estimated to be 540 million euro, equivalent to 0.8% of the total costs of health care in the Netherlands. Before, OA was thought of as being mainly driven by wear and tear of the articular cartilage within the synovial joint. In recent years, it is shown that not only cartilage, but also the subchondral bone, ligaments, the synovial fluid, and surrounding muscles are involved in the OA process. Although the exact aetiology is still unknown, OA is in general characterized by loss of articular cartilage, osteophyte formation, and subchondral bone sclerosis. Clinically, OA is characterized by joint pain and limited joint function. OA can affect all synovial joints, but is most common in the knee, the hip and the hand joints. Given the predominance of OA in the knee joint compared to other joints, the main focus in scientific studies have been on the knee joint, as is the current thesis

Exercise for knee osteoarthritis pain:Association or causation?

Exercise is universally recommended as a primary strategy for the management of knee osteoarthritis (OA) pain. The recommendations are based on results from more than 100 randomized controlled trials (RCTs) that compare exercise to no-attention control groups. However, due to the inherent difficulties with adequate placebo control, participant blinding and the use of patient-reported outcomes, the existing RCT evidence is imperfect. To better understand the evidence used to support a causal relationship between exercise and knee OA pain relief, we examined the existing evidence through the Bradford Hill considerations for causation. The Bradford Hill considerations, first proposed in 1965 by Sir Austin Bradford Hill, provide a framework for assessment of possible causal relationships. There are 9 considerations by which the evidence is reviewed: Strength of association, Consistency, Specificity, Temporality, Biological Gradient (Dose-Response), Plausibility, Coherence, Experiment, and Analogy. Viewing the evidence from these 9 viewpoints did neither bring forward indisputable evidence for nor against the causal relationship between exercise and improved knee OA pain. Rather, we conclude that the current evidence is not sufficient to support claims about (lack of) causality. With our review, we hope to advance the continued global conversation about how to improve the evidence-based management of patients with knee OA.</p

Exercise for knee osteoarthritis pain:Association or causation?

Exercise is universally recommended as a primary strategy for the management of knee osteoarthritis (OA) pain. The recommendations are based on results from more than 100 randomized controlled trials (RCTs) that compare exercise to no-attention control groups. However, due to the inherent difficulties with adequate placebo control, participant blinding and the use of patient-reported outcomes, the existing RCT evidence is imperfect. To better understand the evidence used to support a causal relationship between exercise and knee OA pain relief, we examined the existing evidence through the Bradford Hill considerations for causation. The Bradford Hill considerations, first proposed in 1965 by Sir Austin Bradford Hill, provide a framework for assessment of possible causal relationships. There are 9 considerations by which the evidence is reviewed: Strength of association, Consistency, Specificity, Temporality, Biological Gradient (Dose-Response), Plausibility, Coherence, Experiment, and Analogy. Viewing the evidence from these 9 viewpoints did neither bring forward indisputable evidence for nor against the causal relationship between exercise and improved knee OA pain. Rather, we conclude that the current evidence is not sufficient to support claims about (lack of) causality. With our review, we hope to advance the continued global conversation about how to improve the evidence-based management of patients with knee OA.</p

Physical Activity and Features of Knee Osteoarthritis on Magnetic Resonance Imaging in Individuals Without Osteoarthritis:A Systematic Review

Objective: To systematically review all studies that have evaluated the association between physical activity (PA) levels and features of knee osteoarthritis (OA) on magnetic resonance imaging (MRI) for subjects without OA. Methods: The inclusion criteria for prospective studies were as follows: 1) subjects without OA; 2) average age 35–80 years; and 3) any self-reported PA or objective measurement of PA. The eligible MRI outcomes were OA-related measures of intraarticular knee joint structures. Exclusion criteria were evaluations of instant associations with transient structural changes after PA. Results: Two randomized controlled trials and 16 observational studies were included. One of 11 studies found that PA was harmfully related to cartilage volume or thickness, but 4 studies found a significant protective association. Four of 10 studies found that PA was harmfully related to cartilage defects, while others showed no significant associations. Two of 3 studies reported a significantly increased cartilage T2 value in individuals with more PA. All 3 studies reported no significant association between PA and bone marrow lesions. Two studies assessed the association between PA and meniscus pathology, in which only occupational PA involving knee bending was associated with a greater risk of progression. Conclusion: Within the sparse and diverse evidence available, no strong evidence was found for the presence or absence of an association between PA and the presence or progression of features of OA on MRI among subjects without OA. Therefore, more research is required before PA in general and also specific forms of PA can be deemed safe for knee joint structures.</p