Osteonecrosis

Osteonecrosis of the knee is a condition where a segment of bone in the knee area dies. This segment is usually the inside part of the thigh bone, but can also be the bottom part or the outside part of the thigh bone.

The cause for osteonecrosis of the knee is unknown but is thought to be related to prior injuries to the knee. Women are three times as likely to develop osteonecrosis of the knee as men, and most people are over the age of 60 when it occurs. If not treated early, this condition can lead to severe osteoarthritis.

Some symptoms you might have if you have this condition are swelling, tenderness, limited range of motion, and increased pain with activity. If you have these symptoms you should see your doctor.

To diagnose this condition, your physician may obtain an X-ray of your knee, a CT scan, a MRI scan, and/or a bone scan, depending on the severity of your symptoms and the amount of information gained by previous diagnostic studies.

For less severe conditions, pain medication, a brace, activity modifications, rehabilitation excercises and rest may be all you need to recover. In more severe situations, however, surgery may be indicated. The different surgical options for osteonecrosis of the knee include:

• Arthroscopic debridement, where the surgeon will clean out the joint space
• Reduction of pressure by drilling small holes into the bone
• Adjustment of weight-bearing area away from site of osteonecrosis
• Replacement of bone surface(s)