Japanese researchers presented a research study this week at the Orthopedic Research Society that showed periodic injections of stem cells delay cartilage degeneration in knee osteoarthritis. While this was an animal model, it fits with our 8 year experience of using stem cells in knee arthritis. We have always thought, especially in patients with more severe knee arthritis, that replacing the “stem cell reserve” in the knee was critical. In this theory of knee degenerative disease, the knee is no longer able to maintain itself due in part to fewer functional stem cells, thus the knee sprials out of control, creating a toxic stew of catabolic breakdown chemicals.
There were some other very good research studies at ORS this year. In another, researchers at Stanford found that “adipokines” (cell signaling chemicals that are more commonly found in obese patients) breakdown the meniscus more than knee cartilage. What’s interesting here is that in heavier patients, we often do see the meniscus fail first. This theory would argue that arthritis in heavier patients is not only mechanical (more weight equals more wear and tear on joints), but also chemical.
In yet another ORS paper, researchers found that short bursts of high intensity activity wear down joint replacement prostheses faster than sustained activity. The concerning part of this study was that fast walking predicted more device breakdown (as measured by a sensor on the patient). What’s the hallmark of the younger and more active patients now being targeted by joint replacement manufacturers? They frequently exercise in more intense bursts, walk faster, run, etc… So these findings are a bit concerning for younger patients with knee or hip replacements who want to remain active.