The degenerative disorder of joints, osteoarthritis is caused due to the degeneration and eventual loss of cartilage resulting in inflammation and pain in joints. It affects various organs such as feet, hands, spine and the weight-bearing joints like knees and hips. In most cases, the exact causes of osteoarthritis are not known and this condition is known as primary osteoarthritis. When the cause is known, the condition is called as secondary osteoarthritis.
Primary osteoarthritis is mainly associated with aging in which water content of cartilage increases and protein base degenerates. Repetitive use of joints lead to irritation and inflammation of cartilage which may cause pain and swelling in joints. In advanced cases of osteoarthritis, there may be total loss of cartilage which may result in friction between the bones, joint pain and limitations in the mobility of joints. The inflammation of cartilage may be because of formation of bony spurs around the joints. As osteoarthritis is a hereditary disease, the genetic factor is important in the development of this disease. The mutation in the ank gene results in decreased levels of pyrophosphate in the joint due to which there is an accumulation of the mineral deposits resulting in development of osteoarthritis
The secondary osteoarthritis may be because of some other conditions or diseases. The main causes of osteoarthritis are obesity, congenital abnormalities of joints, repeated joint injuries or surgery, diabetes, gout and some other hormone disease. Obesity is one of the most powerful risk factors for the osteoarthritis of knee. It causes an excessive mechanical stress on the cartilage which may result in breakdown and loss of cartilage resulting in inflammation and pain in the joints.
Repeated trauma to the joint structures such as cartilage, bones and ligaments can cause early development of osteoarthritis. The injured joints in knee and hip are more susceptible to this disease. In addition to this, gout is among the important causes of osteoarthritis. In gout, there is deposition of uric acid crystals in the cartilage. It may cause irritation and inflammation of cartilage leading to pain and stiffness of joints. In psudogout, there may be the deposition of calcium pyrophosphate crystals.
Beside these causes, abnormally formed joints may cause development of osteoarthritis. Some people are born with congenital abnormalities in joints. Such joints are susceptible to mechanical tear, resulting in early degeneration and loss of cartilage. Osteoarthritis of hips is usually associated with design abnormalities of these joints.
The disorders related to hormonal imbalance such as growth hormone and diabetes can also cause early degeneration of cartilage giving rise to secondary osteoarthritis.
