Age and osteoarthritis : Osteoarthritis is a common problem in the community. It has several important risk factors of which one of the most important risk factor is age. Association between age and osteoarthritis is as below.
1. Osteoarthritis is less prevalent in people below 45 years. Type of osteoarthritis seen in this group usually affect single joint. The most common cause of this is trauma and injury.
2. As the age advances the chance of getting osteoarthritis also increases this is seen up to 65 years .
3. In elderly more joints are involved compared to young people who predominantly show affection of single joint.
4. Radiological evidence of osteoarthritis is seen in people under 40 years even if they do not have symptom.
5. In people aged over 70 years more than 50 percentage will have osteoarthritis of hand.
6. Joint are protected from osteoarthritis by several mechanism, these protectors fails with age.
7. One of the important protective mechanism is cartilage in the joint, as age advances there is thinning of cartilage in the joint. So the joint experience increased stress with load.
8. Muscle that bridge the joint protect the joint from increasing stress, as age advances there is weakening of the muscle strength.
9. As a part of ageing ligaments stretch, so they cannot absorb the stress.
Sex difference in osteoarthritis
1. In mild osteoarthritis there is no gender difference
2. Female predilection is seen in severe grades of osteoarthritis
3. Severe disease is seen in older age groups in knee and hand osteoarthritis.
4. Older women are at increased risk for osteoarthritis of all joints ,it is seen in sixth decade,this is due to loss of female sex hormone after menopause.
