Osteoarthritis (OA) is the most common form of arthritis in the United States,1 affecting approximately 30.8 million adults.2 The World Health Organization (WHO) estimates that globally 9.6% of men and 18% of women older than 60 years are affected by OA.3
In addition to chronic pain, the progression of OA is associated with disability, especially in major weight-bearing joints such as the knee and hip.4 According to the WHO, OA is expected to become the fourth leading cause of disability by 2020 due to aging populations and increases in life expectancies.3 Thus, emerging studies are focusing on public health aspects of OA prevention.5
In an interview with Rheumatology Advisor, David T. Felson, MD, MPH, professor of medicine at Boston University School of Medicine in Massachusetts, and Jos Runhaar, PhD, postdoctoral scholar at the Erasmus MC University Medical Center in Rotterdam, the Netherlands, reflected on important considerations in population-based prevention strategies for OA and knowledge gaps that still exist in this field.
Rheumatology Advisor: What are the main risk factors of developing OA? Are hereditary factors at play?
David T. Felson, MD, MPH: The main risk factors are older age and obesity. Women over age 50 are at higher risk for OA than men, and joint injury is a major risk factor. OA is heritable in a joint-specific manner. If a person’s parents had hand OA, he or she will be at high risk for that type of OA, but not knee or hip OA.
Rheumatology Advisor: What preventative strategies can be employed by patients at higher risk of developing OA?
Dr Felson: The main preventive strategies include: 1) keeping weight down, since obesity is a major risk factor for knee and hip OA, and 2) staying active. Muscle conditioning may help prevent disease.
This is a bit complex in that persons who have sustained major injuries such as an anterior cruciate ligament or meniscal tear are at higher risk for further injury. So, low-impact activities and muscle strengthening are best.
Rheumatology Advisor: How early in the disease course should preventative strategies be implemented and why?
Dr Felson: Generally, people are not motivated to prevent OA until they have had some joint pain. Secondary prevention, in which a person already has some symptoms and wants to prevent further disease and pain, should be the target. Efforts at prevention should start with the earliest symptom, which often serves as a teachable moment for individuals affected by OA.
Rheumatology Advisor: Which population-based preventative approaches/programs could be implemented for OA? Are any such programs, or guidelines, already in place at the national level?
Dr Felson: Preventative efforts for OA are shared with other chronic diseases such as heart disease and diabetes. They include weight loss and exercise interventions. The Arthritis Foundation has had some appropriate programs and articles on OA prevention.
Rheumatology Advisor: Which considerations should be taken into account when designing a preventative trial for OA?
Jos Runhaar, PhD: When designing a preventive trial for OA, clinicians should carefully select the intervention and test its preventive effect; when targeting participants for a (primary) preventive trail, researchers select individuals without the disease and without symptoms. These individuals, not patients, cannot experience any benefits from the tested intervention, as they have no symptoms to be relieved. This makes engaging these people in the intervention and ensuring adherence a real challenge. In addition, there is still an ongoing debate about acceptable and feasible outcome measures in OA, as the disease develops slowly, even in high-risk populations.5,6
Rheumatology Advisor: What types of population-based preventative strategies have proven most successful for OA?
Dr Runhaar: From a community perspective, population-based approaches to OA prevention might be superior to individualized approaches focused on high-risk individuals.5
Two major targets for population-based preventive approaches are reducing overweight/obesity and preventing joint injuries. However, since OA develops slowly, long-term studies will be required to evaluate the preventive effects of such population-based approaches.
Rheumatology Advisor: What types of studies still need to be conducted to provide a deeper understanding of the effectiveness of population-based preventative strategies for OA?
Dr Runhaar: Our understanding of preventive strategies for OA prevention is still poor. Thus, it would be helpful to add patient-reported outcome measures or standardized radiography to population-based intervention studies focused on the prevention of obesity.5
For preventive strategies targeting high-risk groups, it is essential to identify modifiable risk factors for OA, preferably individuals with (1) a strong association with OA development, and (2) a high prevalence, and to not limit our efforts to just the knee joint.
Interviews have been lightly edited for style and clarity.
- Felson DT, Lawrence RC, Dieppe PA, et al. Osteoarthritis: new insights. Part 1: the disease and its risk factors. Ann Intern Med. 2000;133(8):635-646.
- Cisternas MG, Murphy L, Sacks JJ, et al. Alternative methods for defining osteoarthritis and the impact on estimating prevalence in a U.S. population-based survey. Arthritis Care Res (Hoboken). 2016;68(5):574-580.
- Woolf AD, Pfleger B. Burden of major musculoskeletal conditions. Bull World Health Organ. 2003;81(9):646-656.
- Zhang Y, Jordan JM. Epidemiology of osteoarthritis. Clin Geriatr Med. 2010;26(3):355-369.
- Runhaar J, Zhang Y. Can we prevent OA? Epidemiology and public health insights and implications. Rheumatology. 2018;57(4):iv3-iv9.
- Runhaar J, van Middelkoop M, Reijman M, et al. Prevention of knee osteoarthritis in overweight females: the first preventive randomized controlled trial in osteoarthritis. Am J Med 2015;128(8):888-895.