The exact cause of the cartilage breakdown seen in this condition is not known - but there are many factors that are thought to play a contributing role.

Age is the strongest risk factor for osteoarthritis. 
It is important to remember that this does not mean it is inevitable as you get older.  Nonetheless, it often affects middle-aged and older people.

Women suffer an increased risk of osteoarthritis particularly after the menopause.  In this situation, it is most common in the hand.

Genetic make-up can be a risk factor. 
Some people may be born with defective cartilage or slight defects in the way that joints fit together - for instance, bow legs or double-jointedness.  As a person ages these defects can cause early cartilage-breakdown in the joint, leading to osteoarthritis.

Obesity in later life is the strongest risk factor for osteoarthritis of the knees.  
The effect of heaviness on the joint is greatly magnified, so even a small weight loss can make an important and significant difference to the weight-bearing joints.

Smokers are at an increased risk of the condition.

If you have had a joint injury in the past. 
Your risk of developing osteoarthritis in that joint may be increased.  Joints which are used repeatedly in particular activities may also be at increased risk.

24/04/2009