Osteoarthritis (OA) is the most common form of arthritis and affects more than 20 million Americans. It's a condition that affects hyaline cartilage, the tough gristle that caps the ends of long bones.
Hyaline cartilage is a complicated substance that consist of a “soup” or matrix made up proteoglycans (complexes of proteins and sugars), collagen, and chondrocytes. Chondrocytes are cartilage cells that both make as well as nourish the matrix.
When OA begins, chondrocytes begin to make destructive enzymes causing cracks or fissures in the cartilage. These are called “fibrillations.”
OA preferentially attacks weight-bearing joints such as the neck, low back, hips, and knee.
So far, the treatment of OA of the knee has not changed in thirty years. It remains primarily symptomatic.
Weight loss, patient education, strengthening and stretching exercise, physical therapy, assistive devices (such as canes, braces, and walkers), analgesics (pain-relieving drugs), non-steroidal anti-inflammatory drugs (NSAIDS), thermal modalities and ice) are standard.
Slightly more aggressive measures such as injections with glucocorticoids (“cortisone”) and viscosupplements (hyaluronic acid … “rooster comb shots”) can be used.
However, there remains a large void because the only remaining option is knee replacement surgery.
While the technical aspects of this procedure have improved, it is still surgery with all the attendant risks of a major invasive procedure in a hospital setting. These include, infection, blood clots, failure of the replacement, and so on. Also, most patients will need a revision procedure (a replacement of the replacement) done. And maybe more than once or twice in their lifetime.
Recently, progress in regenerative medicine procedures have provided hope that there is an alternative to joint replacement.
Once a patient has undergone a thorough evaluation and was through the conservative treatments, consideration as to whether they may be a candidate for either platelet-rich plasma (PRP) should be considered. PRP is an ultraconcentrate of a patient's own blood that contains a high concentration of platelets, cells that contain a plethora of growth and healing factors.
Recent anecdotal reports indicating that PRP may be of benefit in alleviating symptoms in patients with OA of the knee are encouraging. PRP may be repeated as often as every three months.
In patients who have not done well with PRP, autologous mesenchymal stem cells (a patient's own stem cells obtained from bone marrow and fat) can be used. Small studies have shown that this treatment may both alleviate pain and restore cartilage growth. A stem cell procedure is much more involved than a PRP procedure since visualization using diagnostic ultrasound and arthroscopy are needed in order to localize the area of cartilage loss and “jump start” the regenerative process by inducing injury. This induction method is what leads to the cartilage reparative process since injury and consequent infection are the first stages in the healing process.