Stem cell procedure nothing new
"Pitcher's Treatment Draws Scrutiny," proclaimed the headline for this week's New York Timesstory about the medical treatment performed on New York Yankees pitcher Bartolo Colon's elbow and shoulder. The Web browser banner for the story was: "Disputed Treatment Used in Bartolo Colon's Comeback." Based on follow-up headlines across the sports world, the point of dispute is muddled at best and entirely misinterpreted at worst.
According to the story, Florida orthopedic surgeon Joseph R. Purita extracted fat and bone marrow stem cells from Colon and injected them into his shoulder and elbow in an effort to treat ligament damage in the elbow and a torn rotator cuff. Judging from the blogosphere -- certainly a precarious science in itself -- it seems the use of stem cells is being characterized as the potentially nefarious aspect of the treatment. A post about the surgery on Bleacher Report is titled "Stem Cell Therapy: Acceptable Treatment or Questionable Performance Enhancer?" Yahoo! Sports went with "Bartolo Colon's stem cell treatment opens a new can of worms."
If stem cells open a new can of worms, then it should have been opened a long time ago. And we'd better add a bunch of other players who have had a stem cell procedure to the scrutiny list. To name just a few: Indians' outfielder Grady Sizemore; Saints' safety Darren Sharper; and here's your All-NBA stem cell first team: Jason Kidd, Tracy McGrady, Amar'e Stoudemire, Allan Houston, and Kenyon Martin.
These are all athletes who have had microfracture surgery, which is a stem cell procedure. In microfracture surgery, tiny holes -- or microfractures -- are drilled in the bone to allow bone marrow to ooze out and, hopefully, repair damaged tissue. The beauty of this technique is in the stem cells inside the marrow. Bone marrow contains a powerful type of stem cells called mesenchymal stem cells. When these mesenchymal stem cells seep out of the bone, they can fix a variety of parts that are really important in the athletic machinery, like cartilage or tendon or bone -- otherwise known as mesenchymal tissues. [The mechanism of repair is not entirely clear. There are two primary theories on the table: 1.) Stem cells themselves may be taken up by native tissue and then grow and multiply into new tissue. 2.) Stem cells might secrete proteins that signal the native cells to multiply into new tissue.]
Perhaps part of the controversy is over the safety of the procedure.
I was actually just talking about this the other day with David Altchek, an orthopedic surgeon at the Hospital for Special Surgery in New York and medical director for the New York Mets. Altchek pointed out that bone marrow stem cells are considered to be a safe form of stem cells to use in medical treatment, compared to embryonic stem cells, about which there are still a lot of questions.
Embryonic stem cells are what's called "pluripotent" stem cells. That basically means they are the utility players of the stem cell world. They can become just about anything depending on where they are needed. Makes sense, since there are all sorts of jobs in an embryo that need to be filled by new cells.
The worrisome part of such wondrous flexibility is that, in addition to being able to play shortstop and center field, pluripotent stem cells may have the potential to become [to overstretch this analogy to the microfracturing point] a clubhouse cancer. Really, there is some concern in the medical community that these undifferentiated cells can turn into a tumor. As Altchek said, "researchers are scared of [some uses of embryonic stem cells], because how do you control what they become?" That is not to say that the use of mesenchymal stem cells is known to be safe under all circumstances, but there is certainly a medical advantage to using Colon's own bone marrow stem cells. [Not to mention less political/ethical controversy surrounding adult stem cells compared to embryonic stem cells.] Thus far, harmful side effects of stem cell treatments seem to be exceedingly rare or nonexistent. And Colon is not exactly a guinea pig, or "stem cell pioneer," as he has been portrayed in some commentaries.
Dr. David C. Karli, a rehabilitation specialist at the Steadman Clinic in Vail, Colo., says the world renowned sports medicine clinic has treated athletes with bone marrow concentrates [taken from the patient's own body, as in Colon's case] that contain stem cells as part of surgical procedures. "The medical literature is just starting to come in from bone marrow concentrates," Karli says, "but there are no serious reported adverse events in the literature to my knowledge." So safety should not be a big point of scrutiny in Colon's case.
What about the reported use of Colon's fat stem cells?
Like bone marrow, fat also contains mesenchymal stem cells with the potential to rebuild bones, nerves and cartilage. The bottom line is there's nothing shady about the use of stem cells in Colon's surgery -- at least not that has emerged in the reporting thus far. Stem cells have been doing their tissue-differentiating work in microfracture surgeries for years. Of course, it's only recently we reporters have written about "microfracture surgery," and not more alarmingly about "controversial 'microfracture' surgery." But it was fair to be cautious in the early days of microfracture surgery, since few athletes who underwent such procedure seemed to return to peak form. But rehabilitation techniques from microfracture surgery are now much more sophisticated [and include Anti-Gravity Treadmills!], and so the procedure now engenders less controversy. I expect the same will happen with many treatments that involve stem cells.
Given bone marrow stem cell treatment is neither entirely new nor particularly controversial in the medical world, there are two other points worth examining: 1.) Does it work for injuries like Colon's? 2.) Is it performance-enhancing?
"This gets into a difficult issue, because no two rotator cuffs are exactly the same," Karli said in addressing the first point. "Does it cure rotator cuffs? I don't know that we can say that. I don't know that there's enough literature with placebos and full trials to say that, but there does seem to be a positive trend. That is different from proof, though. With what we've seen in our clinic and in my experience in discussing it with others who have done it ... bone marrow concentrates do seem to augment tissue to get healthier."
And the second point is pretty much an unknown at this stage. Stem cell injections are implicitly on the 2011 World Anti-Doping Agency prohibited list [section M3.2] as they are "normal cells" that would fall under the ban on "the use of normal or genetically modified cells" without a therapeutic use exemption. Indeed, there are theoretical doping applications of stem cells, since muscle is one of the tissues that mesenchymal stem cells can help to grow. But stem cell treatments are not banned by baseball, and there is thus far no evidence that stem cells have been successfully used for undue muscle growth.
So, as far as I can tell, the real controversy in the story is that Purita, the doctor who treated Colon, admits to using human growth hormone -- which is banned by baseball -- in nonathlete patients. Unless he's fibbing on that point, then I'm not sure what the scrutinizing and disputing is about.
Bone marrow concentrates do contain natural "growth factors" that can stimulate the healing and growth of tissues, but they do not contain the kind of synthetic HGH that is banned in sports. That would have to be added to the treatment by the doctor, and Purita insists that in Colon's case it wasn't. Plus, adding HGH is not a standard or crucial component of the treatment, so there's no reason to suggest that the procedures would only have been worthwhile if HGH was included. In fact, there is a dearth of research on how helpful synthetic HGH might be in medical treatments like those that Colon underwent.
The last time a new and controversial medical procedure hit the headlines --platelet rich plasma therapy (PRP) -- it also turned out to be neither new nor particularly controversial in and of itself. The controversy there really stemmed from Anthony Galea, the doctor administering the PRP to athletes, who was arrested in October 2009 and later indicted on charges he treated athletes with unapproved drugs, including HGH, that were sometimes mixed into the PRP. In actuality, PRP is exceedingly noncontroversial. It was developed in the 1970s and has been useful in treating tennis elbow and jumper's knee, with no harmful side effects.
Sports fans and athletes should consider stem cell treatments on their own merit, aside from the particular doctor who administered stem cells to Bartolo Colon. If the history of PRP headlines on sports pages is a guide, though, it's probably already too late for a level-headed assessment.
