Back in February, we reported on how thousands of people are visiting hundreds of clinics in American cities and some Canadian centres to get an expensive, unproven, same-day stem cell treatment to ease pain and restore flexibility in their arthritic or banged-up knees.
The BMAC (bone marrow aspirate concentrate) procedure involves extracting mesenchymal stem cells from a patient’s pelvis, spinning them in a centrifuge and then re-injecting them into the damaged knees. The treatment can cost anywhere from $2,000 to $10,000 per injection, even though there are no published reports from high-level clinical trials to indicate it works.
We are, however, getting closer to knowing the truth.
Dr. Shane Shapiro, an orthopedic surgeon at the Mayo Center for Regenerative Medicine in Jacksonville, Florida, has published the results of a 25-person clinical trial in which patients with osteoarthritis received an injection of stem cells in one knee and a saline solution placebo in the other — unaware of which was which.
The results are less than conclusive. As reported in the American Journal of Sports Medicine:
“Study patients experienced a similar relief of pain in both BMAC- and saline-treated arthritic knees. Further study is required to determine the mechanisms of action, duration of efficacy, optimal frequency of treatments, and regenerative potential.”
According to Dr. Shapiro, this leads to two possible interpretations. One is that the BMAC procedure was no better than placebo (because both knees got equally better). The second is that stem cells have a systemic effect (which some animal and human studies suggest) and can go to where needed — so that stem cells injected into the left knee could also make the right knee feel better.
Dr. Shapiro stresses that his study doesn’t prove the latter. It’s still just a theory.
Clearly, what’s needed is a double-blind, randomized controlled clinical trial in which each participant is assigned to receive either the BMAC treatment or a placebo by chance with neither the patient nor the doctor knowing who gets which so that the results can be objectively compared. Until then, we won’t know whether the BMAC procedure actually relieves pain and repair knees.
It should also be noted that the Mayo clinic used the most promising stem cells for their injections. Instead of just drawing and concentrating bone marrow and then reinjecting it into the patient, Dr. Shapiro’s team tracked the number of stem cells and tested their viability before injecting them into a patient’s knees. A patiently likely would not get that level of quality assurance from a busy clinic trying to treat as many patients as quickly as possible.