Treatment Of Osteoarthritis of the Knee
Osteoarthritis is wear and tear degeneration of cartilage in the knee joint. Our knee joints are covered with articular cartilage. This cartilage can wear down over time. The rate of cartilage wear depends on injuries, activity level, weight and genetics. Over time the cartilage starts to wear and can cause pain, stiffness and limited function. Depending on your level of pain and dysfunction there are many treatment modalities available for you.
Treatments currently available for osteoarthritis include:
- Activity modification
- Weight loss
- Anti-inflammatory medications
- Nutritional supplements and glucosamine
- Physical therapy
- Corticosteroid injections
- Viscosupplementation injections
- Partial knee replacement surgery
- Total knee replacement surgery
High impact activities of often painful for people with osteoarthritis and can cause more rapid progression of the arthritis. Examples of high impact activities are: jogging, singles tennis and high impact aerobics. People with osteoarthritis are often more comfortable exercising on an elliptical trainer or swimming. Stationary bicycle is good for patients with arthritis unless you have arthritis of the knee cap causing pain in the front of the knee.
Weight loss can be very difficult for many people, but decreasing your weight can take significant stress off of your knees and can help both with symptoms and with slowing of progression of your arthritis.
Anti-inflammatory medications such as ibuprofen or Aleve can help to reduce the pain associated with arthritis. These medications work well, but are typically not recommended on an ongoing basis as they can have side effects. Intermittent use of these medications can be quite useful
Physical therapy is good for the muscles and ligaments around the knee. Physical therapy can also help improve motion of the joint and decrease inflammation in the joint. Physical therapy can exacerbate symptoms for some people and should be stopped if symptoms are worsening
Injections of corticosteroid are very frequently used for the treatment of arthritis. These injections work in most people to help decrease the inflammation and pain in the knee joint. Cortisone injections work in most people, but the length of time that these injections work for is very unpredictable. Some people get 6 months or more relief from an injection, but others only get days of relief. Some people have more pain for the first few days after the injection. Too many cortisone injections can cause damage to the cartilage in the joint.
Viscosupplementation injections have available and FDA approved for treatment of osteoarthritis of the knee for over 10 years. These typically consist of a series of three injections into the knee joint. These injections act as a lubricant in the knee joint. The results of these injections have been very unpredictable. Somewhere in the range of 60% of people have a good response to these injections. People that have a good response to these injections typically get 6 – 12 months of relief from the injections. There is a small risk of have an inflammatory reaction to these injections. The risk of this inflammatory response is approximately 1% and can cause more pain and swelling in the knee, sometimes requiring the knee to be drained.
Arthroscopic surgery is typically a treatment for meniscal tears and not a good option for arthritis of the knee. With arthroscopic surgery I can remove torn fragments of articular cartilage or meniscus, but I cannot put new cartilage in the knee. The results of arthroscopic surgery for arthritis have been no better than physical therapy, anti-inflammatory medications or injections. Approximately 10% of patients will get worse after arthroscopic surgery. Arthroscopic surgery works well to get rid of mechanical symptoms such as locking of the knee.
Partial Knee Replacement Surgery
Partial knee replacement surgery has been around since the 1970s but has gained popularity in the last 5 years with improved implants and improved surgical techniques. Partial knee replacement surgery resurfaces only one third of the knee joint. This is typically done for the inner part of the knee but can also be done for the outer part of the knee. Approximately 20% of patients who come in with osteoarthritis are candidates for partial knee replacement surgery.
Partial knee replacement surgery has advantages and disadvantages when compared to full knee replacement surgery.
- Smaller operation
- Less medical complications
- Less pain
- Shorter hospital stay
- Faster recovery
- Feels more like a normal knee after recovery
- Better range of motion of the knee
- Leaves 2/3 of the knee alone
- Higher risk of needing another operation in the future
I use the Mako Robot to perform partial knee replacements. This system allows me to get a CT scan of your knee prior to surgery and create a 3D model of your knee. The implants are put into the 3D model and I can plan very precisely where to put the implants in order to optimize your result. In the operating room the pre-operative plan can be fine tuned to make sure that your ligaments are properly tensioned. The implants are then put in very precisely using a robotic arm. Surgery takes between 1 and 1 ½ hours and we typically get you up and walking the same day as your surgery. Most patients that have partial knee replacement surgery are discharged from the hospital the morning after their surgery and go home using a cane. The average person uses the cane for 2 weeks. Most people can be back at work in 1 – 2 weeks. You need to do physical therapy for the first 6 weeks, but typically by 6 weeks after surgery people are about 80% recovered and are back to all routine activities. Full recovery takes approximately 3 months.
Partial knee replacement surgery leaves the ligaments and the remaining 2/3 of the knee alone. Failure of partial knee replacements is due to either loosening of the implants or progression of arthritis in other areas of the knee. National registries have shown that approximately 1 in 10 patients who undergo partial knee replacement surgery will need another operation within 10 years of their initial surgery. This is higher when the surgery is done by a surgeon who does not do partial knee replacements frequently and is lower when done by surgeons with a high volume of experience with partial knee replacements. Partial knee replacement surgery is a technically more demanding operation than a full knee replacement and many surgeons who perform full knee replacement surgery do not perform partial knee replacement surgery.
Total Knee Replacement Surgery
Total knee replacement surgery is the gold standard in surgical treatment for people with osteoarthritis. Knee replacement surgery has been around for almost 50 years. Implants and techniques continue to improve allowing patients with knee replacements to return to almost all regular activities.
Knee replacement surgery resurfaces the end of femur and tibia with metal caps and has a plastic liner in between these to act as the bearing surface. The undersurface of the knee cap is often also resurfaced.
Surgery typically takes between 1 and 1 ½ hours. At the Hospital for Special Surgery this is typically done with an epidural anesthetic so patients do not require general anesthesia. Patients are typically sedated during the procedure. Our physical therapist will get you out of bed and standing the same day as your surgery. Most people are in the hospital for 3 days and then either go home or go to an inpatient rehabilitation center prior to going home.
Knee replacement surgery does an excellent job of reducing pain and increasing function, but the recovery from knee replacement surgery takes time. People typically use a cane for 4 to 6 weeks after surgery. Everyone requires physical therapy for at least 6 weeks after surgery. Typically by 6 weeks after surgery people are walking without a cane, but are still complaining of swelling, warmth, and stiffness in the knee. Approximately 10 – 20% of people are still taking prescription pain medications 6 weeks after surgery. By 3 months after surgery people are walking normally and are back to most regular activities. People are still often dealing with swelling in the knee and stiffness after sitting for long periods of time. The muscles are often still weak 3 months after surgery. Comfortable stair climbing is often the last thing that returns. People continue to get better for 6 to 12 months after knee replacement surgery. Although the recovery can be long the results are usually very good. 90% of modern day knee replacements are expected to last 20 years or longer.