Ask the experts - osteoarthritis

Q. My husband needs to have hip-replacement surgery because he has been diagnosed with osteonecrosis. What exactly is osteonecrosis, and how might his condition have developed?

A. Osteonecrosis means bone death. Bone is living tissue and requires nutritient- and oxygen-rich blood to survive. If the bone’s supply of blood dwindles or is cut off, bone becomes soft and can collapse. The most common site of osteonecrosis is the hip, but it may also occur in the shoulder, upper arm, knee, wrist, or ankle.

Risk factors for osteonecrosis include overuse of corticosteroid medications and heavy alcohol use. Both promote the development of fatty deposits in blood vessels, which can clog the vessels and interfere with blood flow.

Injuries to a person’s bone, such as a hip fracture or dislocation, can also disrupt the flow of blood to the affected bone.

People who have rheumatoid arthritis or lupus are among other individuals who have an increased risk of developing osteonecrosis.

An early symptom of the condition is pain, which a person experiences when putting weight on a particular joint. Over time, the pain may occur when the individual is at rest, and it may interfere with the joint’s range of motion.

Q. I was recently diagnosed with osteoarthritis, and I’m worried about making my condition worse. Are there certain types of exercise or household activities I should avoid?

A. Actually, staying active is one of the most important steps you can take to prevent arthritis-related pain and disability and improve your cardiovascular health. Appropriate exercise strengthens the muscles that support your joints and helps you maintain range of motion. Weight-bearing exercise, such as walking, also helps preserve bone density and prevent osteoporosis. Walking outdoors in the sun will help your vitamin D supply, which is needed for strong bones.

You should avoid high-impact exercise, such as jogging and tennis, which are hard on the joints and can increase swelling and pain. Walking, using training equipment, or walking in a swimming pool can provide an opportunity for a high-intensity (but low-impact) workout that won’t hurt your joints. Experiencing pain while you exercise or in your hip or knee the next day may indicate that your workout is too strenuous.

Try not to sit or stand for long periods. If you have a desk job, change positions frequently and get up and stretch or walk around every 30 minutes or so. Don’t spend long hours sitting watching TV. If you have knee arthritis, don’t bend your knees too much or too quickly when performing daily activities. If possible, sit down to retrieve objects from the floor.

Questions are selected that reflect the wide variety of health problems of general interest. We cannot respond specifically to the personal health concerns of an individual.