What is OA

What is Osteoarthritis?

Arthritis is simply the medical term for joint inflammation and there are about 150 different types of arthritis. You need to make sure you know what type of arthritis you have as each type is treated differently and you will start to understand more about what is osteoarthritis when you start to categorize them.

Arthritis disorders divided into 3 categories:

  1. Inflammatory; for example rheumatoid arthritis
  2. Metabolic; for example gout.
  3. Non-inflammatory; for example osteoarthritis

Osteoarthritis (OA) has several different names, for example degenerative joint disease (DJD), degenerative arthritis or wear and tear is all commonly used. It is called spondylosis when it is in the spine (not to be confused with spondylitis which is an inflammatory arthritis!).

All of these mean the same thing and what you should realise that all this is simply ‘medical jargonise’. This is a language that is only meant to be understood by other medical people so they can baffle non medical people and can appear cleverer than they really are!  I think degenerative joint disease or wear and tear are the best terms as they describe the condition and explain what it is.

What is Osteoarthritis

In order to help your understanding of what is osteoarthritis here is a VERY brief anatomy lesson. This is a picture of a healthy hip and a hip with osteoarthritis. The blue area is cartilage whicht covers the ends of the bones. It reduces friction and acts a shock absorber.

What is Osteoarthritis

The blue area on the healthy joint is the articular cartilage which degenerates in osteoarthritis.

Osteoarthritis is a wearing of this cartilage so eventually, in severe cases, bone rubs on bone. Cartilage has no nerve endings in it so movement or injury is never painful to the actual cartilage but will cause a lot of pain from the bone underneath which has masses of nerve endings. Bruised bone is very painful and in osteoarthritis bone can become chronically bruised.

Nerves and blood vessels develop at the embryonic stage along the same pathways and travel round the body together. Cartilage has no blood supply as well as no nerve supply. Without blood, the nutrients and building blocks for repair do not get delivered to the cartilage and nor can waste products be taken away.

Cartilage gets it’s nutrients from the thick viscous fluid inside the joint which gets squished about as you move the joint. This pressure helps ‘feed’ the cartilage and that is why it is important to keep moving a joint. But it does mean cartilage has very limited ability to regenerate or repair itself and helps explain why osteoarthritis is always progressive  and continues to get worse, no matter what you do.

What is Osteoarthritis Doing to the Surrounding Soft Tissue?

In most cases of osteoarthritis the wearing of the joint (i.e. the bone pain) is not the only cause of pain. In fact, in the early stages, it is rarely the cause of the pain!

Another quick anatomy lesson.

Muscles, tendons and ligaments are affected by osteoarthritis

Muscles create movement, tendons attach muscle to bone and ligaments are the straps that hold the joint in the correct position at all times during a movement.

The muscles, tendons and ligaments (the soft tissue) around the joint give pain too. This happens because as the cartilage wears the function of the joint alters. You will start to use the joint differently and use adjacent joints more. Unfortunately as you change the way you move your joint you will irritate and inflame the soft tissue around it as you alter the pull through them. This will cause pain and stiffness in the affected soft tissue.

As the soft tissue becomes painful you change the joint function further, usually by limiting the movement. Unfortunately soft tissue likes to be used and limiting the movement causes more pain and stiffness when you do try to use it. (If you are not sure about that ask someone who has had a cast on a broken bone what it was like to get it moving again.)

The movement in soft tissue also improves the blood supply to it, especially in the removal of blood from which is mainly done by the mechanical squashing the veins which pushes the blood long back toward your heart. As the blood is not being moved about in the soft tissue healing is limited so the soft tissue becomes even more painful. So you move it even less and so the blood supply is compromised even more.

The end result of all these things is a rapidly downwards spiral as the joint gets stiffer and more painful so is used less making it even more stiff and painful.

Please note that most Doctors when answering this question What is Osteoarthritis refer to primary and secondary osteoarthritis. They say that primary osteoarthritis is simply part of the aging process and that secondary is because there is a cause such as trauma or obesity.

I challenge this view under Causes of Osteoarthritis.

I hope that answers the question What is Osteoarthritis for you. If it did please give us the thumbs up Facebook. If you want to know how it affects individual joints please click on the links below or find out what the signs and symptoms of osteoarthritis are.

Hip                Knee                Ankle                Foot & Toes

Shoulder      Elbow              Wrist                Hand, Finger & Thumb