A number of recent studies have pointed out a disturbing trend. The first showed that the prevalence of knee pain has increased over the last 20 years, independent of age or body mass index. What was surprising is that this was not accompanied by an increasing incidence of osteoarthritis noted on x-ray.
Another study- probably more disturbing- indicated that only a few years ago, between 300,000 and 350,000 knee replacement surgeries were performed annually. Today, that number has risen to an astonishing 500,000. And within 10 years, some estimate there could be as many as 3.2 million annual knee replacement surgeries.
What's more surprising is that this operation is being done on a much younger population group... boomers under the age of 60.
While the technology is improving, it is still worrisome because the "shelf-life" of replacements is still unknown. What that means is revision procedures- replacements of the replacements will have to be done conceivably two and three times during the course of a given person's life.
That exposes the patient to a number of potential complications.
So what can be done?
Osteoarthritis (OA) is the most common form of arthritis and affects more than 20 million Americans. Osteoarthritis adversely affects hyaline articular cartilage, the tough gristle that caps the ends of long bones.
Hyaline cartilage is made up of a matrix consisting of a combination of proteoglycans (complexes of proteins and sugars) and chondrocytes. Chondrocytes are located within the matrix... picture a gelatin mold with grapes. The gelatin is the matrix and the grapes are the chondrocytes. Chondrocytes are cartilage cells that manufacture matrix under normal healthy circumstances. They are responsible for nourishing the matrix as well.
When OA develops, a distinct change in the joint environment occurs. Chondrocytes begin to elaborate destructive enzymes causing cracks in the cartilage. These are called "fibrillations."
Why OA develops is still poorly understood. Since investigators have difficulty figuring out how the disease develops, it is no surprise that the treatments for the condition are relatively inadequate.
Symptomatic treatment with non-steroidal anti-inflammatory drugs, analgesics, braces, physical therapy, exercise, injections of glucocorticoids and viscosupplements, can buy time they do not restore articular cartilage.
There needs to be a treatment that bridges the gap and possibly may forestall the need for knee replacement.
In the latter part of the 20th century, work on adult mesenchymal stem cells, cells with the ability to differentiate into connective tissue were found to be an integral component of connective tissue repair.
These cells are present in a number of areas including the bone marrow, fat, deciduous teeth (baby teeth), and the periosteum (outside lining) of bone.
Increasing number of anecdotal reports, case histories, and small population studies (Wei N, Beard S, Delauter S, Bitner C, Gillis R, Rau L, Miller C, Clark T. Guided Mesenchymal Stem Cell Layering Technique for Treatment of Osteoarthritis of the Knee. J Applied Res. 2011; 11: 44-48) have confirmed the potential value of mesenchymal stem cells as a viable treatment for osteoarthritis.
Quite obviously, there need to be large multi-center controlled studies to validate these findings and it is hoped they will be offered in the near future.
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