Knee Osteoarthritis (OA): Common Questions
What is Knee Osteoarthritis (OA)?
Our understanding of Osteoarthritis (OA) and the way it is managed has changed over the years. OA has commonly been thought to refer to joint inflammation; however, inflammation is not the primary cause or driving factor. Inflammation can occur during this process but OA is considered a chronic, progressive condition of the joint breaking down. This joint breakdown used to be described as “wear-and-tear” but recent research better describes it as a result of our bodies’ failed attempts to repair damaged joint tissues, specifically cartilage and bone. OA is the most common type of arthritis and it affects the knees more than any other joint.
Symptoms can include:
Morning stiffness for ~30 minutes
Persistent joint pain related to activity
Limited range of motion
Crepitus / joint noises
Bone enlargement and tenderness
What are the risk factors for developing knee OA?
Previous knee injuries – ACL tears regardless of surgery increases the risk along with other orthopedic injuries especially when combined i.e. ACL and meniscus injury.
Advancing age – Increasing after 45 years.
Excessive weight – Not just due to the extra load but also the metabolic factors associated with obesity.
Occupation – Repetitive squatting and kneeling >2 hours per each day can have a cumulative effect.
Gender – Women are more at risk than men after the age of 45.
Family history – Genetics play a role in the development of OA.
Sedentary lifestyle – Muscle weakness particularly through the quadriceps.
Does knee OA only occur in older adults?
Although the rates of knee OA are higher in older adults, it does occur earlier in life. But it is important to know that it can be somewhat prevented. Reducing your risk factors such as weight management, prevention of serious injuries, maintaining regular activities and strengthening appropriately all help to prevent or reduce symptoms of knee OA.
Is knee OA just wear and tear and normal to getting older? No, it is a multi-factorial condition which can be delayed and in some circumstances prevented via management of your risk factors. It is not a normal part of aging or an inevitable condition. Many individuals avoid OA symptoms throughout their life.
My knee hurts, do I need x-rays to be assessed and diagnosed? An x-ray isn’t always necessary or required with knee pain or even when OA is suspected. X-rays do not do a good job of assessing or diagnosing pain. Nor are they good for prognosis unless in severe cases or if a fracture is suspected. In the case of a traumatic or sudden onset of knee pain, The Ottawa Knee Rules are a guideline used to determine if an x-ray is warranted. Speaking to your family doctor or physiotherapist regarding your symptoms is a good first step in the assessment of your knee pain. There is not one test used for being diagnosed with OA but rather is done through a clinical assessment involving your symptoms and joint function.
Is running bad for my knees? Running can actually be good for your knees. If the impact of running is applied gradually and consistently, your body will adapt to the stress and becoming stronger. No impact for a long time or unexpected higher loads than normal are more of a risk factor for symptoms to arise. Remember to gradually introduce new activities and avoid too much too soon or else it’ll be too little too late!
Is OA caused by wet, cold weather?
Climate does not cause or cure arthritis however warmth can be soothing for symptoms as it is for many individuals who do not have OA.
I’ve been diagnosed with knee OA, will I need surgery? Most people living with knee OA do not get a knee replacement. This is generally reserved for severe cases that have been symptomatic for a long time.
What is the best and first line of treatment of knee OA?
Exercise! Along with weight management and education, these are the most important pillars of rehabilitation for knee OA. The goal is to modify any risk factors present to reduce pain, improve your joint function and quality of life.
Exercise is focused on strengthening around the hip, knee and ankle but can vary depending on the individual’s physical assessment.
Weight loss can play a large role if you are overweight. Obesity is linked to OA even in non-weight bearing joints indicating that it is not just a function of the extra load on the joint but what the biological tissue does to the joint. Maintaining a healthy diet and physical activity will help to prevent this risk factor from worsening.
Bottom Line Evidence based guidelines strongly recommend exercise for people with osteoarthritis. Remember that surgery isn’t the most common answer to OA!
An assessment by a physiotherapist will help to determine what specific areas you should focus on and determine an optimal level of exercise to avoid acute flare ups. Your physio may also provide adjunct treatment to facilitate better movement and exercise such as manual therapy or electrotherapy to reduce pain temporarily.
Alentorn-Geli, E., Samuelsson, K., Musahl, V., Green, C. L., Bhandari, M., Karlsson, J. (2017). The association of recreational and competitive running with hip and knee osteoarthritis: A systematic review and meta-analysis. Journal of Orthopedic & Sports Physical Therapy, 47(6): 373-378.
Fransen, M., McConnel, S., Harmer, A. R., Van der Esch, M., Simic, M., Bennell, K. L. (2015). Exercise for osteoarthritis of the knee: A cochrane systematic review. British Journal of Sports Medicine, 49: 1554-1557.
Heidari, B. (2011). Knee osteoarthritis prevalence, risk factors, pathogenesis and features: Part 1. Caspian Journal of Internal Medicine, 2(2): 205-212.
Messier, S.P., Gutekunst, D. J., Davis, C., DeVita, P. (2005). Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis. Arthritis & Rheumatism, 52(7), 2026-2032.
Silverwood, V., Blagojevic-Bucknall, M., Jinks, C., Jordan, J. L., Protheroe, J., Jordan, K. P. (2014). Current evidence on risk factors for knee osteoarthritis in older adults: A systematic review and meta-analysis. Osteoarthritis and Cartilage, 23: 507-515.
Timmins, K. A., Leech, R. D., Batt, M. E., Edwards, K. L. (2017). Running and knee osteoarthritis: A systematic review and meta-analysis. The American Journal of Sports Medicine, 45(6): 1447-1457.
Zhang, W., Moskowitz, R. W., Nuki, G.,Abramson, S., Altman, R. D., Arden, N.,…Tugwell, P. (2008). OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based expert consensus guidelines. Osteoarthritis and Cartilage, 16(2), 137-162.