There are specialized braces that can be helpful in some cases of knee arthritis. These braces are designed to create a force which transfers load from an area of the knee where the cartilage is more worn, to an area of the knee where the cartilage is less worn. These braces are helpful in cases where there is still some cartilage remaining in the knee, and the pressure of the brace causes less discomfort than the knee arthritis.
There are less invasive surgical procedures available which can be helpful in some cases. These include arthroscopy. Arthroscopy requires only small incisions around the knee which allow the insertion of small instruments, which are about the size of a pen or pencil. With arthroscopy, degenerated and worn cartilage can be trimmed and smoothed, which reduces the source of inflammation. Additionally, the lining of the knee (the synovium), can be trimmed, and this also decreases inflammation. Patients who have knee arthroscopy almost always go home the same day. Recovery from surgery occurs over a couple of weeks. Unfortunately, the benefit of arthroscopy decreases as the degree of arthritis increases. In advanced arthritis, arthroscopy is of little value.
It is now possible to transplant articular cartilage from one location to another. Healthy cartilage, from an area of the knee that does not bear weight, can be transplanted into another area of the knee where weight-bearing cartilage has been damaged. Cartilage transplantation is best for localized areas of damaged cartilage in an otherwise healthy knee. Unfortunately, in most cases of osteoarthritis and rheumatoid arthritis, the degeneration and wear of articular cartilage involves the majority of the joint surfaces. Cartilage transplantation is not a good option in such cases.
Some cases, where the leg is imperfectly aligned, can be treated by an osteotomy. An osteotomy is an operation that cuts the bone, either above or below the knee, and re-aligns the knee to a better position. This is a bigger operation than an arthroscopy and patients usually stay 1 or 2 days in the hospital. It takes 6 to 8 weeks for the bone to heal. Physical therapy is usually required to restore knee motion and strength. Complete recovery takes a number of months. An osteotomy is a good operation, especially for younger patients, and those where the leg is clearly not straight and the cartilage wear is confined to one portion of the knee. Unfortunately, the success of an osteotomy decreases as the degree of arthritis increases.
In a few cases, only a portion of the knee joint surfaces have worn out and need to the replaced. When only a portion of the knee is replaced, this is called a uni-compartmental arthroplasty. Patients usually stay 2 or 3 days in the hospital and it takes a couple of months for the knee to recover. Physical therapy is usually required to restore knee motion and strength. Unfortunately, in most cases of arthritis, the joint surfaces are diffusely worn. Uni-compartmental arthroplasty is, therefore, less commonly performed than total knee replacement.
Arthrodesis / Knee Fusion
In cases when the risk of failure of total knee replacement is considered to be very high, an arthrodesis, or knee fusion may be recommended instead. In this operation, the ends of the femur and tibia bones are cut flat, the cut ends are pressed together such that the leg is just slightly bent, and then held in this position by pins, or plates and screws. Over a couple of months the ends of the bones grow together, hence the term knee fusion. The knee fuses in a nearly straight position and cannot be bent. Although the knee no longer moves, it is not painful and most patients walk with only a slight limp.