What is osteoarthritis

Average rating:

Arthritis means inflammation of the joints. Osteoarthritis (OA) is the most common form of arthritis in the UK. OA mainly affects the joint cartilage and the bone tissue next to the cartilage.

Understanding joints

A joint is where two bones meet. Joints allow movement and flexibility of various parts of the body. The movement of the bones is caused by muscles which pull on tendons that are attached to bone.
Cartilage is a hard, smooth tissue that covers the end of bones. Between the cartilage of two bones which form a joint there is a small amount of thick fluid called synovial fluid. This fluid 'lubricates' the joint which allows smooth movement between the bones.
The synovial fluid is made by the synovium. This is the tissue that surrounds the joint. The outer part of the synovium is called the capsule. This is tough, gives the joint stability, and stops the bones from moving 'out of joint'. Surrounding ligaments and muscles also help to give support and stability to joints

What causes osteoarthritis?

All normal joints and joint
tissues are constantly undergoing some form of repair because of the
wear and tear that is placed on them through our daily activities.
However, in some people, it seems that this repair process becomes
faulty in some way (perhaps because of severe wear and tear to the
joints or a problem with the repair process) and OA develops.

In
joints with OA, the joint cartilage becomes damaged and worn. The bone
tissue next to the cartilage can also be affected and bony growths can
develop around the joint edges. These growths are called osteophytes
and may be seen on X-rays. The joints and the tissues around the joints
can also become inflamed. This inflammation is called synovitis.

Factors that may play a role in the development of OA include:

Age.
OA becomes more common with increasing age. It may be that the state of
the blood supply to the joint and the state of the natural mechanisms
of repair become less efficient in some people as they become older.
Genetics. There may be some inherited tendency for OA to develop in some people.
Obesity. Knee and hip OA are more likely to develop, or be
more severe, in obese people. This is because there is an increased
load on the joints and a potential for more joint damage.
Your sex. Women are more likely to develop OA than men.
Previous joint injury, damage or deformity. For example,
this may include previous joint infection, a previous fracture (break
in the bone) around a joint, or a previous ligament injury that caused
a joint to become unstable.
Occupational overuse of a joint. For example, OA of the knee
may be more common in elite athletes and elbow OA may be more common in
people working with pneumatic drills.