What is knee osteoarthritis (OA)?
It is the most common type of arthritis that affects the knee. It is often described as ‘wear and tear’ of the joint. It generally develops slowly over time with symptoms gradually becoming worse as the years go by.
Who is most often affected by knee OA?
- People over 50
- Ladies are twice as likely to be affected
- People who are overweight
- People who have suffered previous knee injury
What causes knee osteoarthritis?
The precise cause is difficult to explain and not much is known about the exact cause. However, there are a number of risk factors to developing knee OA
- Previous cartilage damage
- Previous tendon or ligament damage
- Pre-existing medical conditions such as gout or rheumatoid arthritis
- Genetic factors. However, no gene has been identified at this moment in time
- Being overweight
What are the symptoms of knee Osteoarthritis?
There are a variety of symptoms of knee OA and they can vary from person to person. The most common symptom that people experience however, is pain in the knee.
How is it diagnosed?
Unfortunately there is no one single test and often it would be diagnosed with a physical examination and potentially an X-Ray.
X-rays can be used to show if there is reduced joint space in the knee. It should be mentioned however that the level damage does not correlate to the severity of the symptoms. This can lead to the counter intuitive result of a knee with apparently minimal damage being painful and a knee with what appears to be severe damage being pain free!
What is unicompartmental knee OA?
This is when only one side of the knee is damaged. It can result in the knee taking on the appearance of becoming increasingly bowed or knocked kneed. It can affect either the inside (medial) or outside (lateral) compartment of the knee joint.
How can it be managed?
Self-management is often the first course of action. Things like weight loss, alteration of activities, healthy diet and exercise.
Did you say exercise is important?
While is may sound like the last thing you should be doing, it has been shown that exercises and especially activities that load the joint can help keep it mobile and reduce symptoms
I heard that running can cause knee arthritis?
It often gets said that running on hard surfaces causes wear and tear in the knee. However, this has never been proven. There is a reasonable level of data that suggests moderate levels of running does not increase the risk of osteoarthritis of the knees and hips for healthy people. There is also some evidence to suggest that running may even have a protective effect on joints.
What about bracing?
Bracing in unicompartmental knee osteoarthritis has been common place for a number of years and evidence is emerging of its effectiveness. The idea behind the braces is to ‘unload’ the damaged side of the knee. This can be done in a number of ways from a rigid frame to strapping. They are often used to help tide people over until surgery can be performed or for people unable to have surgery.
What about insoles?
Insoles can be used to help treat knee conditions. They can achieve this by altering the mechanics of the lower limb. Like most treatment this does not work for everyone as it will be dependent on your biomechanics and general alignment. The relationship between foot function and knee alignment is complicated and not fully understood. However, insoles are often tried as they can be effective in some people and are a simple and cost effective initial treatment.
What is that noise my knee makes?
The noise that sounds like creaking or cracking is what we call ‘crepitus’. Research has found that 99% of knees make some kind of noise but the exact cause of these noises has not been found. However, there is a number of theory’s.
• Popping of air bubbles in the joint
• Snapping of tendons past each other
• “Stick-Slip” phenomenon
While the noises can be concerning generally they are not associated with damage being caused and is not associated with the progression of knee arthritis.
However it should be added that there is always exceptions especially when trauma is concerned. In cases such as an ACL tear or meniscal injury they can often result in a pop sound when it occurs and clicking noises afterwards.