By Nathan Wei
Conservative approaches to osteoarthritis of the knee include non-steroidal anti-inflammatory drugs, good quality forms of glucosamine and chondroitin, physical therapy, corticosteroid injections, viscosupplementation (injections of lubricant into the knee), and bracing.
For people who do not respond to these measures, there are more aggressive approaches available. The first is arthroscopy. This is a procedure where small telescope is inserted into the knee. Using specialized cutting instruments, damaged and diseased tissue is removed and flushed out of the knee. For many patients this affords relief.
If the arthritis damage is limited to one side of the knee, an osteotomy (removal of a wedge of bone to help the bones of the knee line up better) can be a very good option. This procedure is best done in patients under the age of 60 who are active and who do not have severe inflammatory changes. The only disadvantage is that because bone is removed, it may make subsequent knee replacement surgery more difficult because there is less bone to anchor the replacement in.
Resurfacing is a procedure where a thin layer of the femur (upper leg bone) and a thin layer of the tibia (lower leg bone) are removed. A layer of metal is applied to the femur and a layer of plastic is applied to the tibia. Sometimes the back of the patella (kneecap) is also resurfaced. This type of procedure is good for people who only have a moderate amount of damage and who have relatively good bone stock.
A relatively new procedure is paste grafting. Here, a hole is drilled in an area of arthritis to expose bleeding tissue. A paste consisting of crushed up bone and cartilage cells is then placed in the hole and the patient is not allowed to bear any weight on the repaired knee for several months. The paste is supposed to promote regeneration of cartilage. Preliminary data is encouraging.
Cartilage plug grafting is a procedure used when there is a single localized defect in the cartilage of the femur. A plug of cartilage is removed from the intercondylar notch of the knee (a non weight-bearing area). The plug is then placed into the cartilage defect in the femur. While this is good for localized defects, it is not useful for large defects due to osteoarthritis.
Autologous cartilage implantation is a procedure where a plug of cartilage is removed from the intercondylar notch of the knee (a non weight-bearing area). The plug is then used to provide cartilage cells which are grown in a laboratory. The patient then undergoes a second surgery where the cartilage defect in the weight-bearing part of the knee is carefully debrided (cleaned), then a patch is placed over this defect and cartilage cells grown from the first harvesting procedure are injected underneath the patch. Cartilage cells then grow over a period of several months. This procedure is good only for isolated cartilage defects and not for generalized osteoarthritis of the knee. Patients must not bear any weight on the leg for at least six months.
Synthetic cartilage plugs can also be inserted. The plug is made of synthetic biodegradable material that permits the patient’s own cartilage cells to grow within the defect. This procedure is best used for younger patients (50 or younger) who have a localized defect. It takes several months for the plug to take hold.
Patients who have a damaged meniscus (cartilage cushion) due to arthritis can have a replacement meniscus donated from a cadaver source. These grafts can last about 4-5 years. The one danger is that the body may reject them.
Total knee replacement is a procedure where the end of the femur and the end of the tibia are removed and replaced with appliances consisting of metal capped with ceramic or plastic. Knee replacements last 12-15 years. A revision of this replacement may be required if the knee replacement is older than 15 years. Recent data indicates that a an exercise program instituted before surgery greatly enhances the chance of success.
Nathan Wei, MD, FACP, FACR is a rheumatologist and Director of the Arthritis and Osteoporosis Center of Maryland http://www.aocm.org He is a Clinical Assistant Professor of Medicine at the University of Maryland School of Medicine and consultant to the National Institutes of Health. For more info: http://www.arthritis-treatment-and-relief.com/arthritis-treatment.html Arthritis Treatment