Osteoarthritis (OA), a painful chronic condition characterized by the wearing away of cartilage in a joint, is the most common form of arthritis, with almost 27 million Americans suffering from the disease. Cartilage, the strong, yet flexible material in joints that protects bones from rubbing against each other, is at the heart of all discussion. Cartilage can be weakened as a result of overuse or old age, or can be permanently damaged due to injury. Damaged or injured cartilage in the long term becomes one of the leading causes of OA. Presently, the most common treatment for damaged cartilage is a repair treatment called microfracture, a process that is only semi-effective, and of which the long-term benefits are not known. Approaching the issue from a completely new angle, Constance Chu, an associate professor at the Cartilage Restoration Center at the University of Pittsburgh, has been working for the past 20 years on new treatments for damaged cartilage that focus on using stem cells to regenerate cartilage tissue.
Microfracture, a procedure that has been growing in popularity of late, works as follows: small holes are punctured into the bone beneath the damaged cartilage, which prompts blood and bone marrow to fill the joints. Bone marrow contains stem cells – cells that are able to grow into other cells – and blood contains other growth-promoting cells. Based on these fundamentals, this process is intended to generate cartilage-like scar tissue to replace damaged cartilage. Unfortunately, this resultant tissue isn’t as strong and doesn’t work as well as real cartilage, and many times will eventually lead to OA. Dr. Chu believes that by increasing the concentration of stem cells when repairing the cartilage, the regenerated tissue will be more similar to the strength and quality of the original cartilage.
Dr. Chu is currently conducting two studies on former racehorses and rodeo horses that tests her theories with concentrated stem cells and compares them with microfracture cases. In one, bone marrow is taken from the horse’s stifle joints (similar to the human knee) and spun in a centrifuge to separate out the part in which stem cells are most likely to be, while also removing excess fluid and other materials. According to Dr. Chu, the benefit of this technique is that it can be performed during surgery and used in treatment. In the second method, stem cells are taken directly from bone marrow and grown in a laboratory, which is likely to yield the best crop of stem cells but takes much longer than the first option. If all goes well, the injured horses will regenerate new tissue by three months. If either of the studies proves to repair tissue better than microfracture, Dr. Chu intends to perform the same tests on humans, which she estimates will begin in two years.
In addition, Dr. Chu is researching ways of detecting cartilage damage before it progresses too far. One of the main obstacles with cartilage repair is that because cartilage doesn’t contain any nerve endings, patients don’t feel pain until minor damage worsens into something much more severe like OA. Dr. Chu believes that if cartilage damage is detected and treated early, it won’t develop further into a more debilitating disease, saving the subject many years of pain and discomfort later in life.
-As reported in the Jan. 4 edition of The Wall Street Journal
-Summarized by Greg Gargiulo