Knee Arthritis and Total Knee Replacement
More than 43 million American adults have doctor-diagnosed arthritis. There are more than 100 different types of arthritis. Osteoarthritis is the most common, and is the “wear and tear” form due to abuse and injury we put on our joints. Researchers say that genetics may play a significant role of osteoarthritis in 40-65 percent of all cases of osteoarthritis. In other words, if your parents have suffered from the effects of osteoarthritis, chances are you will too.
Being overweight plays a substantial role in developing osteoarthritis. Every pound of body weight is magnified 3 times across the joint between the femur and tibia. The knee cap joint is even more weight sensitive with weight being magnified 5 times body weight. A 150 pound person can place up to 450 – 750 pounds of pressure across the knee joint. Exercise is extremely beneficial for maintaining joints and bones. Types of exercises that are low impact are ideal for individuals suffering with arthritis. These exercises include walking, swimming, elliptical, bicycling, and water aerobics.
There are also significant differences in arthritis between women and men. Women account for more than 60% of doctor diagnosed cases of arthritis. Women are three times less likely than men to undergo knee replacement even though they suffer from more knee pain and resultant disability.
There are several forms of non-operative treatment available for knee arthritis. Ranging from low-impact exercise, weight loss, using heat or cold, supplements (glucosamine), pacing your activities, physical therapy and use of assistive devices such as a cane. Medical treatments include use of nonsteroidal medications (Aleve or Motrin), acetaminophen (Tylenol), corticosteroids injections, viscosupplementation injections (synvisc or orthovisc), bracing, sleep aids, pain medications, and surgery. Surgical options include partial and total joint replacement.
Partial knee replacement is a great option for individuals suffering from arthritis isolated to one area of the knee joint. Partial knee replacements exist for the inner compartment, outer compartment or the kneecap joint. The most common location to develop isolated arthritis is the medial or inner compartment of the knee. In the right patient, medial compartment replacements can last as long as a total knee replacement.
Total knee replacement is a great option for those individuals who are suffering from end stage osteoarthritis and have failed the non-operative treatments listed above. Typically the pain limits the ability to performing work activities or leisure activities. In the later stages, it can even make getting a restful night sleep difficult.
Partial Knee Replacement
Partial knee replacement is a great option for individuals suffering from arthritis in one compartment of the knee. Partial knee replacements exist for both the inner, outer and knee cap compartments. The medial (inner) compartment replacement is by far the most common partial knee replacement performed. When performed correctly, in the ideal patient, it can last as long as a total knee replacement.
Typically one suffering from medial compartment arthritis has pain limited to the inner side of their knee. They may have developed a bowleg deformity as well. Patients suffering from isolated patello-femoral arthritis will have pain on the front part of their knee and typically have the most difficulty getting up from a low chair or going up and down stairs. Ideal individuals for the partial knee replacement are of ideal body weight with medium to low physical demand.
No ligaments are cut as a process of the performing the replacement. This gives a very natural feeling knee that does not feel artificial. I commonly hear patients stating that they feel as though they have their “old knee back” before they started having the pain and disability from arthritis.
A medial compartment replacement can be performed through a minimally invasive approach that allows for quicker recovery post-operatively. Most patients spend only one night in the hospital. The physical therapist will see the patient the morning after the surgery to help patients walk with an assistive device and teach the how to walk safely. Once patients are discharged home, a home health physical therapist will come to the patient’s home to help continue the healing process.
Patello-femoral (kneecap) replacements although can work well, unfortunately do not enjoy the same durability or quick recovery as a medial compartment replacement. Recovery of a patellofemoral replacement is closer to that of a total knee replacement, yet do not have the same durability as a total knee. Patello-femoral replacements are typically reserved for the younger patient who are not ready for a total knee, but understanding in 10 or so years will likely require a revision to a total knee replacement.
Every patient is different, and how quickly they recover differs significantly as well. At two weeks, most medial compartment patients can expect to be using a cane outside the home, and no assistive device in the home. Most patients are driving their vehicle at 3 weeks. Depending on work requirements, most patient who have a desk position are back to work at 4 weeks.
Risks of knee replacement include deep venous thrombosis, pulmonary embolus, infection, blood loss, neurovascular injury, fracture, anesthetic risks, medical complications (heart attack or stroke), possible need for revision surgery, and death.
Partial knee replacements work very well in the ideal patient. It is a great option for isolated compartment osteoarthritis.