Treatment Options for the Arthritic Knee
Treatment for knee arthritis will allow you to increase your mobility and improve your lifestyle by reducing or eliminating pain.
Conservative treatment options:
- Tylenol (Acetaminophen)
- Anti-inflammatory medication
- Anti-rheumatoid arthritis medications
- Oral steroids
- Pain medication
- Injections of steroids such as cortisone or depomedrol
- Injections of hyaluronic acid – these injections for osteoarthritis are thought to improve the shock-absorbing quality of the knee fluid, by restoring lubrication and fluid in the joint, which can help temporarily relieve pain.
- Ice packs, rest and elevation of the knee
- Ambulatory aids (canes, crutches, walkers)
- Lifestyle changes such as exercise and diet
Surgical options are generally considered when conservative treatment fails and pain and functional limitations persist. There are several options available. These include:
- Unicompartmental (or partial) knee replacement
- Total knee replacement
Arthroscopic surgery of the knee is a day surgical procedure. Small incisions, about 4-5mm in size, are placed around the knee. A “scope” is then placed into the knee. The scope is connected to a small camera that projects an image of the knee on a TV monitor. The entire inside of the knee can be visualized.
This technique is very handy in that it allows the surgeon to assess the joint and evaluate the damage. In addition, the surgeon can perform treatment. This treatment may come in the form of removing loose cartilage, cleaning up loose bodies or repairing the ring cartilage known as the meniscus. In arthritis, usually the damage to the knee is irreparable, however most patients have substantial pain relief after the arthroscopy.
This procedure is especially useful for patients who have minimal signs of arthritis on x-ray but have severe pain. The reason for pain can often be discovered with an arthroscopy.
- Knee Arthroscopy
- Arthroscopic View of Good Knee Cartilage
- Arthroscopic View of an Arthritic Defect (small area of exposed bone)
Often arthritis is isolated to one particular side of the knee. In this case an osteotomy can be considered. An osteotomy is a surgical procedure where the forces of the knee are redirected to decrease pressure on the side where most of the arthritis is located. This is done by cutting a wedge of bone from the thigh bone (femur) or the shin bone (tibia). After the wedge is removed, the remaining bone is put together and fixed with some type of hardware. When the bone is put together it realigns the forces across the knee joint. An osteotomy relieves pain by allowing the healthy part of the knee take the majority of the force applied during standing or walking. With the advances in knee replacement surgery the osteotomy is not often performed. Although, this surgery has historically met its goal, pain relief is usually temporary lasting up to five years. In addition, this procedure requires significant bone healing which in some cases can take a substantial amount of time.
Unicompartmental Knee Replacement :
Unicompartmental (or partial) knee replacement (UKR) is a less invasive knee surgery where only one side of the knee is replaced. It is indicated for patients who have degenerative arthritis isolated to the inside or outside portion of the knee joint. The criteria a patient must meet for this type of replacement is much more rigid than for a total knee replacement. However, for the right patient, this procedure works well. Patients who have an unstable knee, too much deformity, too restrictive range of motion or rheumatoid arthritis are not good candidates for this procedure.
For the right patient, the minimally invasive partial knee replacement offers several potential benefits:
- Resolves arthritis pain
- Maintains two-thirds of the natural knee
- Minimally invasive procedure
- Proven procedure
- Medium to long-term pain relief
- Maintains more of the healthy elements of your knee, resulting in a more natural feel during activities
- Possibly reduced hospital stay
- Usually requires less pain medication following surgery
- X-ray showing arthritis on the right side of the knee, notice the bone on bone in comparison to the other side.
- X-ray after a UKR
- UKR implants
Total Knee Replacement :
A total knee replacement is the most common of all surgical options. In 2001, 323,448 total knee replacement were performed (according to Solucient, Inc. 2001). The total knee replacement is actually a resurfacing operation. In other words, the diseased surfaces of the joint which come in contact with each other are essentially capped with metal and plastic.
There are three primary components to the total knee implants. These include the femoral, tibial and patellar components. These components can be cemented to the bone with polymethylmethacrylate (PMMA). PMMA is a polymer that is mixed at the time of implantation. An alternative to cementing is to rely on initial fixation of the components to bone. This can occur with “press fitting” the implant onto the bone or with screws. The non cemented implants have a roughened or porous surface at the bone/implant interface. With healing, bone grows into the porous surface of the implant and locks the components in place. Cementing the implants is the most common form of fixation due to it predictability.
The femoral component is typically made of a metal called cobalt chrome alloy. This is a very hard and durable material, allowing it to withstand the massive loads and cycles a knee endures on a daily basis. The other advantage of this metal is its ability to wear a highly polished surface that is durable. Other materials, such as titanium alloy cannot hold a polish for a long period of time as this metal is too soft and can become scuffed. Another material worth mentioning is Oxinium. This is the trade name for a new composite material of zirconium and its oxide called zirconia. This is actually a ceramic on metal. The ceramic is an extremely hard material and can hold a polish better than the metals. This material, although promising, is too new to know it actual implanted performance.
The tibial component is usually made up of two main pieces, the tibial tray and the tibial insert. The tibial tray is typically made of titanium or cobalt chrome. There are arguments for and against each of these materials and as of now, probably either material is good. The tibial insert is the bearing between the femoral and tibial components. The insert is made of a plastic called polyethylene and is fixed to the tibial tray. There are many different configurations of the tibial component depending on the manufacturer and the surgeon’s preference. The insert can come already attached to the tray or can come separate and placed on the tray at the time of surgery. Some tibial components are all polyethylene.
The patellar (knee cap) component is also made of plastic (polyethylene). In the past, metal backed patellar implants were used, however, the majority of patellar components are all polyethylene.
The choice of implants is tailored to fit each patient’s needs. However, in general, my preference for the total knee is as follows. First of all, I use cemented implants. Fixation is dependable in nearly all cases. The femoral component material of choice is cobalt chrome alloy. The tibial component material is either cobalt chrome or titanium alloy. Both of these type of materials have performed very well. The the patellar component is all polyethylene. This configuration provides the most reproducible results in my practice.