What is Osteoarthritis?Osteoarthritis (OA) is the leading type of arthritis affecting millions of patients. OA of the knee is the most common cause of disability in the aging population. It results from the degeneration of cartilage, which covers the ends of the bones in the knee. The loss of cartilage can result in a loss of normal alignment, increased friction with motion, loss of impact absorption, and loss of fit. All of these things contribute in some measure to the ultimate result of a painful, poorly working knee. It is believed that the average person takes about one million steps per year on each leg. OA of the knee can make each of these steps painful, eventually limiting function and lowering the quality of life.
Current Osteoarthritis Continuum of Care Therapies
Non-Medication TherapyMany doctors will treat the beginning pain of OA with simple non-drug therapies such as suggesting weight loss, exercise, use of a cane, proper footwear and braces. Research has shown that weight loss and exercise together are better than either one alone for relieving the pain. These interventions are good low-cost, self-directed and low risk. Usually the non-drug interventions are not able to reduce the pain and restore function by themselves but they are useful and can be helpful when used along with certain medication treatments.
Medication TherapyFor early stages of OA, over the counter NSAID’s (Nonsteroidal Anti-Inflammatory Drug) such as, acetaminophen (Tylenol®) or ibuprofen (Advil®) may be useful for moderate pain relief. Other prescription medications are available for more severe OA pain, however all medications have side effects and risk factors. Constant use of these drugs may enhance side effects and must be closely monitored by your doctor.
While there are numerous reports in the literature relating to meniscus and cartilage repair there is still debate on their usefulness. Other procedures, such as microfracture treatment, can be used together with the ones mentioned on patients with bone-on-bone OA to help in the growth of new cartilage. The results of these additional therapies are variable, especially as we age. At best, arthroscopic treatment can be effective for some patients with early or moderate disease. For most patients with advanced disease, arthroscopic therapies either provide temporary relief or don’t work in relieving pain. Biologic therapies, such as autologous cultured chondrocyte transfer, are not recommended for patients with OA of the knee at this time.
Uni-compartmental Knee Replacement:
Uni-compartmental replacements have several benefits including less post-operative pain, shorter recovery time, and potentially less cost over total knee replacements. They are technically more difficult to perform than a total knee replacement. Implanting a uni-compartmental involves the removal of bone from the effected side of the knee. This can make a subsequent total knee replacement more difficult. Recently, there has been interest in minimally invasive uni-compartmental replacement techniques. These operations utilize a small incision (3 inches) and remove very little bone on the tibia, although there are still parts of the implant that use cement to keep them in place, which can loosen over time. Uni-compartmental replacements have an advantage of shorter operating room time and greater patient satisfaction. However, there is a learning curve for these operations and the survivorship, revision rates, and degree of difficulty converting to a primary total knee replacement are not yet known.
Total Knee Replacement:
Total knee replacement is the standard treatment for advanced stages of OA of the knee. A total knee replacement involves removing the surfaces of the femur and tibia, and replacing them with a metal femoral component and metal and plastic tibial component. Total knee replacement is the surgery of choice for people where OA has affected all compartments (medial, lateral, patellar) of the knee, but is also being used in patients where OA affects one part of the knee, most often in the medial compartment. When surveyed one year after surgery 80% of patients seem to be satisfied with the procedure. The down sides of a total knee replacement are the typically long recovery period after surgery (several months), high overall cost ($20,000-45,000), and the limited life of the implant may result in a more difficult revision surgery.