What is it?
Osteoarthritis of the knee is a result of loss of normal joint surface. The damage can happen as a result of a severe injury or it can be a “wear and tear” process over a long period of time. Often if the alignment of the leg is not balanced (in other words if the knee is bow-legged or knock-kneed) the forces on the joint can be asymmetric and one side of the joint can wear excessively. When, as a result of any of these problems, there is not a normal joint surface cartilage there is loss of shock absorption and the normal smoothness and slipperiness that is normally present. OA also reduces the ability of the natural lubricant in joints, synovial fluid, to cushion and act as a shock absorber.
Loose pieces of cartilage or bone that are shed from the roughened joint surface can cause pain catching and joint inflammation that results in knee swelling. The swelling in osteoarthritis is a result of excessive joint fluid in the knee from inflammation caused by reaction to joint debris. The swelling causes the sensation of tightness and fullness around the joint and can make it difficult and painful to bend the knee. When arthritis has been present in a joint for a long time, the joint can become contracted and stiff and not allow full motion even if there is not any swelling in the joint. With long standing arthritis the bone can become deformed as well contributing to unbalanced forces on the joint and further worsening the problem.
Treatments without surgery: Some relief is usually possible with these methods.
Activity moderation
Even a damaged arthritic joint can often tolerate a certain amount of activity. There may be a limit to what the joint will stand without causing pain, but within that limit satisfactory function may or may not be possible, depending of an individual patients age, general health, activity level and expectations. Decisions are not made solely on x-ray or MRI appearance since it is well known that some patients with really severe looking x-rays have symptoms that are manageable to them. This is because they are functioning within the limits and boundaries of what their joint will tolerate.
Weight loss
This helps because the joint must not bear so much load with every step. Your muscles will also fatigue less if you are lighter and better conditioned. Weight loss can have a major effect in controlling symptoms. Though exercise to produce weight loss can be difficult with a painful joint, certain exercises that are low impact such as bicycling, swimming and aquatic exercise (such as water aerobics) can be well tolerated by many. Eating less and smarter is also a key component. If you need advice about diet, consultation with your primary care MD or a dietician might be very helpful.
Exercise
By improving the strength and flexibility around a joint, it is possible to decrease the load that the joint surface must absorb. This is because the muscles can absorb a portion of the load that your leg must accept. The stronger your muscles are, the more energy they can absorb. The more that your muscles can absorb is less that your bones and joint have to bear. Improving flexibility in the muscles and the joint through exercise is also very helpful. Gentle persistent stretching is best.
Shock absorption
Standing and walking on softer surfaces can help to make up for the lack of shock absorption present in an arthritic joint. In the same way, wearing shoes with extra shock absorption or shoe inserts with gel can help. Evaluate your shoe wear carefully. Many shoe companies have models with excellent cushioning designed for this purpose. One particularly useful shoe brand has been GDFEY (online at gravitydefyer.com)
Heel Wedges
In patients with medial osteoarthritis of the knee (the most common variety of knee arthritis) it has been proven that placement of a felt lateral heel wedge in the shoe can decrease symptoms, sometimes dramatically. This works because the heel wedge makes a subtle change in alignment of the leg, allowing more weight to go through the lateral (outside) part of the knee. The wedges are inexpensive, low risk, and can be placed inside most shoes. They are often worth a try and should be worn regularly or at least during periods of most activity.
Bracing
Knee braces for arthritis are designed to support the joint and in some cases to “unload” the most damaged part of the joint. These braces, though somewhat bulky, are lightweight and can be very useful in active patients with arthritis. Typically, patients use the brace during the times when they are most active on their knee, not constantly. These are prescription braces and can be expensive but are generally covered to some degree by insurance. They can be very effective and in some cases allow patients to avoid the risks and inconvenience of knee surgery. Over the counter knee braces help some people. Mild arthritis can be helped by some soft knee sleeves in certain patients. The sleeves we have found most helpful are Reparel sleeves and they are available in our office or online. More severe arthritis tends to need more support involving hinged braces. Some of these are available without prescription but give less support than prescription models. Nonetheless, they may be sufficient for some patients.
“Over the counter” supplements
The use of over the counter supplements containing glucosamine and chondroitin sulfate are popular and effective in relieving for many people. There is enough scientific information available to conclude that at least 50% or more of people who try this gain some significant, sometimes dramatic relief. Claims that some of these manufacturers make about rebuilding cartilage are less well proven. There have not been many problems with side-effects from this type of supplement, but when they occur problems are mostly stomach related. There are many different brands, many of which contain other substances as well. Dependable brands include Osteo Bi-flex and Cosamin DS. It is available without prescription at pharmacies and other places where vitamins and supplements are sold. It is important to understand that it may take 4-6 weeks for the effects to be felt. Therefore, sometimes other medications are recommended or prescribed to help until the supplements “kick in.”
“Fish oil” supplements
There is an emerging body of evidence that such “omega 3” supplements reduce inflammation throughout the body and that they may have beneficial effects on joint pain. There is more
evidence regarding their effect on rheumatoid arthritis than osteoarthritis so far but it seems likely to me that there is some effect on osteoarthritis as well. In addition to the effect on your joints, there is much evidence of beneficial cardiovascular effects of omega-3 fish oil supplements. So for all these reasons they are often recommended.
Non-steroidal anti-inflammatory medications
Medications in this group include commonly used ones such as aspirin, ibuprofen (Advil, Nuprin, Motrin) and naproxen (Aleve, Naprosyn). There are many other prescription choices including Celebrex, Feldene, Lodine, Mobic and others. It is not unusual for one medication to work better than others for any individual patient. There is no way to tell which will work best for any particular person. These medications work as a pain medication by blocking chemical reactions that contribute to pain. These chemical reactions that are blocked also decrease inflammation and swelling. For these medications to work effectively on swelling and inflammation they need to be taken regularly. Depending on which medication is used, that may mean taking your medication up to four times a day. These medications can be very effective but are not without risk. If you think you need to take them chronically, I believe that your primary care provider needs to prescribe them for you and follow you carefully to prevent and treat any side effects.
Side effects of these medications can include nausea, upset stomach (gastritis or ulcer formation), bleeding from the stomach or intestines, hypertension and other effects. If you are going to use this type of medication, it is necessary that you accept and review the information given to you by your pharmacist about possible risks of taking them.
Joint injection: steroid injection
The idea of injection of steroid medication into a joint is to put a concentrated dose of anti-inflammatory medication directly into the site of inflammation. Such injections are usually given mixed with local anesthetic (numbing medication) to provide some initial temporary relief. Depending on the nature and severity of the problem, relief can last from weeks to months or longer. It is not completely predictable. If successful and long-lasting, injection can be repeated.
Joint injection: “joint fluid therapy” hyaluronate
This treatment is repeated injection of a substance called hyaluronate into the knee. This substance is similar to the fluid that occurs naturally in the knee – synovial fluid – which helps to lubricate the knee, reducing friction and protecting from pain. There are different versions of this type of injection including Supartz, Synvisc, Hyalgan and others. I use Supartz (www.supartz.com) because it has the longest track record of safety and efficacy and has the highest concentration of active ingredient per injection. The treatment is a series of 3-5 injections into the knee, one a week for three to five weeks. On average, relief lasts 6 months or more and most insurance companies will authorize repeat treatment if needed after 6 months. Not everyone improves with this treatment. Less severe arthritis responds best, but some patients with even very severe arthritis can get significant relief.
You should not have this treatment if you have a known hypersensitivity (allergy) to sodium hyaluronate preparations, if you are allergic to bird (avian) proteins, feathers, and egg products, or if there is an infection or skin disease in the area of the injection site. If you have allergies, as above, there are alternative injections that we can discuss for you.
Joint injection: Platelet Rich Plasma (PRP)
Platelet rich plasma injections are injections of a patient’s own blood which is drawn in the office, specially prepared and centrifuged to result in a concentrated portion of the blood which is rich in platelets and growth factors. This type of injection has been widely used over a number of years for treatment of acute injuries, chronic tendonitis problems and for treatment of arthritis. There are now enough quality studies that I think it is a reasonable treatment alternative. Studies have shown that results of PRP injection are better and longer lasting than hyaluronate injections. Recent studies and experience suggest use of PRP along with hyaluronic acid injections may be the best alternative. Unfortunately insurance companies still consider PRP injection investigational, so cost for PRP injection must be out of pocket for patients who would like this treatment.
Surgical Options
Surgery can range from knee arthroscopy to remove loose and torn pieces of cartilage or bone in mild to moderate cases to total knee replacement in severe cases.
Arthroscopy
This is helpful in mild to moderate cases generally where there are mechanical symptoms of catching, locking and sudden sharp pain. The purpose is to remove or smooth areas of irregular tissue in the joint. Sometimes there are associated meniscus tears as well. By removing this tissue, pain and inflammation are decreased in successful cases. In some cases of very localized joint surface injury (post-traumatic arthritis) some arthroscopic techniques can stimulate an improved scar cartilage to grow back where the natural cartilage surface has been damaged by direct injury. When symptoms are caused by wearing away of the ends of the bone and severe bony erosion and deformity exist, arthroscopy is much less successful. Whether arthroscopy makes sense in your situation depends on other factors as well which we can discuss.
Osteotomy
This is considered in patients with knee deformity who have joint wear limited to one side of the knee. This treatment involves correcting a bowlegged or knock kneed deformity by cutting the bone around the knee and straightening (correcting) the deformity. This allows the joint load to be re-distributed onto the healthier side of the joint. Results can be excellent from this operation. It does take a relatively long time to recover after surgery since weight-bearing (walking) on the involved leg depends on how long it takes for the bone to heal completely and can be 3 months or longer. This operation is useful for patients who are too young for joint replacement, have arthritis localized to one side of the knee and a deformity overloading that side or who wish to avoid risks associated with joint replacement.
Joint replacement “total or partial knee replacement”
Joint replacement involves cutting off the worn-out joint surfaces and replacing them with new slippery, smooth and well-aligned surfaces. The replacement surfaces are made of metal and hard plastic. The surfaces are applied to the cut bone surfaces by precise cuts and by bone cement. After joint replacement, early motion and weight bearing can usually be permitted. Recover is somewhat shorter than with osteotomy and most patients can walk independently more quickly. However, the time until full activity depends on age, health and the severity of your arthritis.
Knee replacement is usually a very durable, reproducible and successful procedure, but there are some very severe complications possible. It is possible for the replacement components to loosen or to wear out. In either situation, revision surgery may be needed. Infection, though rare, if it occurs can be a terrible problem and require removing the knee replacement, weeks of IV antibiotics and repeat surgery later to reinsert a knee replacement.