Newsletter

Knee osteoarthritis (OA) is an extremely common condition, especially with aging, and one that we’d group into the “normal, wrinkles on the inside” category due to only about half of people diagnosed reporting symptoms. We know that exercise is beneficial and recommended as a treatment intervention, however there is still some uncertainty on why it is effective. The common narrative is that OA is a condition of “wear and tear” leading to “bone on bone”. However, we know this is not always the case as there is plenty of evidence demonstrating that more active people such as runners and weightlifters present with healthier cartilage and less pain as they age. Nevertheless, we find many patients are not very eager to begin exercising and loading their painful joints out of fear or misconception. Therefore, we think it is important to take the time to adequately explain how exercise can help patients reduce symptoms, reach their goals, and improve their quality of life. 

 

In this review, we will be looking at a paper published by Bandak et al, exploring the effect of exercise on inflammatory activity in knee OA. The authors randomly assigned 33 people greater that the age of 40 and a confirmed clinical diagnosis of knee OA into two groups: 

1. Functional and individualized exercise therapy program supervised by a trained physical therapist 3x/week for 12 weeks

2. Control group receiving no attention for 12 weeks but specifically instructed not to alter their habitual physical activity levels. 

The researchers assessed pain levels and inflammatory levels (synovitis and bone marrow lesions using MRI) pre and post the 12 week intervention and found no changes in the inflammatory activity but found significantly reduced pain levels in the intervention group compared to the control group. The authors conclude by saying, “Inflammatory activity was unchanged and pain was reduced in the patients with knee OA adhering to 12 weeks of exercise therapy compared to a no-attention control group. The reduction in pain was not explained by changes in inflammatory activity. Overall, the results suggest that exercise is not harmful in knee OA.”

 

So…what does all this mean? Well, I certainly thought there would be a change in joint inflammatory levels for the better in the intervention group, as shown by several other studies (which this article does reference and address). Like many interventions that reduce pain, it is difficult to pin down exactly what is the mediator for change. This may simply be due to the multi-factorial complexity of pain that is unique to each individual. Exercise interventions are also likely to have an impact on multiple interacting systems between mechanical, neurological, and cognitive processes resulting in various effects, including altering perception of pain. No matter the cause, test subjects still had reduced pain after 12 weeks of guided exercise, as well as no change in inflammation which can comfort fearful patients who believe strengthening and loading their painful joints will worsen symptoms. Overall, this study gives us more reason to be confident in prescribing an exercise program, physical therapy, or personal training. 

 

Adapted from: The Effect of Exercise Therapy on Inflammatory Activity Assessed by MRI in Knee Osteoarthritis: Secondary Outcomes from a Randomized Controlled Trial (Bandak et al, 2020). The Knee. 2021;28:256-265