Joe Norton PT

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What is Osteoarthritis?

This blog will be the first in a series intended to educate you on Osteoarthritis(OA). I hope to provide knowledge on what is OA and how best to treat it.

OA  is a very common condition of the knee joint. The knee joint is a connection between the tibia(shin) and the femur (thigh). It is made up of several structures: the bones, cartilage, synovial fluid and a joint capsule. The cartilage in a joint covers the ends of the bone. It is smooth and allows for the gliding of the bones. It is strong and flexible.

Cartilage receives nutrition and blood supply from the synovial fluid. Think of the cartilage like a fluid filled sponge. When it is compressed the fluid is expelled. When the pressure is relieved the fluid is sucked back in.

So when we go for a walk, the pressure from the activity causes fluid to be expelled from the cartilage into the joint capsule. When the pressure is removed, the fluid returns to the cartilage. This routine fluid exchange from exercise is needed to maintain the health of the joint and cartilage.

Cartilage breakdown is the hallmark of OA. In a healthy joint, the tissues are continuously breaking down and getting built back up. When there is an imbalance of greater tissue breakdown than repair cartilage thins, cracks or disappears. This may occur due to overuse, injury or age. Being overweight and having a family history of OA may also increase the likelihood of the condition, but are not destiny and can be prevented or overcome with proper joint health.

Common symptoms of knee OA are pain, stiffness, swelling and instability. Pain typically occurs with weight bearing activities like walking, squatting and stairs, Stiffness will occur in the mornings, after prolonged periods of sitting and by the end of the day. Swelling can often be a silent indicator of stress on the cartilage. Cartilage is aneural, which means when it is injured or irritated it cannot sense pain. Instead, cartilage will communicate its issues via swelling during, or a few hours after or the next day following activities. Instability is the symptom of weakness or wanting to give out. The swelling or pain from OA, or secondary effects of weakness in the thigh muscles can cause this symptom.

Since OA often results in pain, individuals frequently stop or reduce their physical activity. However, we know joints need routine loading in the form of exercise to maintain or promote cartilage wellbeing or recovery. Additionally, inactivity can lead to weakened muscles which may make OA symptoms worse. Therefore, exercise therapy for knee OA is a safe and effective solution that does not require potentially harmful and costly medications, injections or surgeries.

In my next blog, I will detail more specifics on the effects of exercise on OA as well as how much and what kind of exercise is needed to manage OA.

References:

  1. https://www.oarsi.org/

  2. https://gladcanada.ca/

  3. https://pubmed.ncbi.nlm.nih.gov/29669488/#:~:text=Physical%20activity%20and%20exercise%20therapy%20not%20only%20improve%20symptoms%20and,%2Dinduced%20anti%2Dinflammatory%20effects.

  4. https://pubmed.ncbi.nlm.nih.gov/29934429/

  5. https://pubmed.ncbi.nlm.nih.gov/30320965/