Do our joints wear out with age? Demystifying Osteoarthritis...

Osteoarthritis is an extremely common condition, affecting millions of people worldwide, and yet it continues to be poorly understood by many, often with outdated concepts throughout healthcare, the media and those impacted directly by the condition.

Common misconceptions as to the cause of Osteoarthritis include that joint cartilage can be worn down by too much activity such as running or sport, or that loss of cartilage causes bone rubbing on bone.

The notion that joints have a certain shelf life in which the loss of cartilage is inevitable and will result in the eventual pain, stiffness, and loss of function that we see in the older population is common.

But is this true?

The cells within our cartilage (as well as all the cells within our body) are in a process of constant turnover, as old cells are replaced with new ones.

Research has shown that rather than an active degradation of the joint structure, we should consider Osteoarthritis as a suppression of the restoration of cells during the normal turnover of tissues. As we age, the process of restoration slows but the demand remains the same. This leads to reduced quality of tissue forming the cartilage. This poorer quality tissue has a higher percentage of water and is easily squashed, eventually becoming thinner, and resulting in joint space narrowing.

For a healthy joint, we would like a positive net turnover (more cells being created than degrading) so that the volume of tissue increases.

The net turnover of cell formation can be affected by various things that occur to the joint either directly or indirectly. If you decrease the restoration process to below the rate of cell degradation, this results in a net negative turnover. If you stimulate the restoration process to be faster than cell degradation you will see a net positive turnover.

Things that stimulate the restoration process:

-        Loading (exercise)

Things that reduce the restoration process:

-        Increasing age

-        Increased inflammation

-        Obesity

-        Low physical activity levels

Things that can increase the rate of cell degradation:

-        Injury or trauma to the joint (including surgery)

-        Shear forces

-        Inflammatory arthritis

Loading (exercise) causes a compressive effect on the cartilage, which stimulates cell activity and therefore optimising the maintenance of the cartilage matrix. It is similar to the way we understand exercise to be beneficial for muscles and the adage “use it or lose it”. The appropriate form of exercise is that which is tolerated (not causing more pain or inflammation) and that allows consistency.

Increased systemic inflammation can be caused by many long-term conditions including obesity. Fat cells (particularly abdominal ones) release adipokines which can increase inflammation. This inflammatory process can interrupt the restoration process of cartilage cells.

So, in short, Osteoarthritis has been shown to be caused by a downregulation of our normal restoration process of the cartilage cells. You can improve your cartilage health by supporting the restoration process through loading (exercise) and reducing the factors that reduce restoration (maintaining a healthy weight, reducing systemic inflammation etc).

By understanding that loading will not “wear out your joints”, you will feel confident to do the very things required to improve your joint health.

If you need assistance in managing your Osteoarthritis, call us on 07 5337 9853 to make a booking with one of our Physiotherapists.