Osteoarthritis: Overview and Risk Factors

Osteoarthritis, also known as degenerative joint disease, is the most common joint disorder. It is characterized by damage of the joint cartilage and abnormalities of the bones surrounding the joint. Unlike in rheumatoid arthritis, inflammation is usually minimal in osteoarthritis. In severe cases, the entire joint surface may be destroyed, with resultant pain and disability.

The most common joints to be involved are the knees, hips, and vertebrae. The joints of the hand are also commonly affected. The most common symptom is stiffness within the joint, typically lasting less than 15 minutes per day. Over time, the stiffness progresses to pain.

Most cases of osteoarthritis occur in the absence of underlying diseases. However, several medical disorders predispose a person to osteoarthritis. These include endocrine abnormalities (e.g., hypothyroidism, diabetes, or mellitus), other joint diseases (e.g., rheumatoid arthritis, gout, or joint infection), and bone diseases (e.g., avascular necrosis or Paget’s disease).

Risk Factors

• Obesity: Obesity increases risk of osteoarthritis of the knee and hip joints.
• Age: The condition is rare in young people, but common in middle–aged and older adults. One–third of people over 65 years old have evidence of osteoarthritis in the knee on X–rays
• Female gender
• Occupation: Hands, hips, and knees are vulnerable
• Genetics: An identical twin of an individual with hand or knee osteoarthritis has double the risk of having the same condition, compared with a fraternal twin.
• Trauma: Repetitive acts increase the risk.
• Pre–existing or anatomical joint abnormality