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Stem cell procedure could be next wave in sports medicine

Drew Pomeranz had a stem cell injection in October for an injured flexor tendon.barry chin/globe staff/Globe Staff

FORT MYERS, Fla. — With a painful shot in October that left him unable to bend his prized arm for days, Red Sox lefthander Drew Pomeranz joined what he and others hope is a transformative development in sports medicine.

At the conclusion of the 2016 season, after dealing with elbow-forearm discomfort that diminished his performance down the stretch, Pomeranz was advised to take a period of rest to let his flexor tendon heal. But beyond a rest-and-rehabilitation protocol, he added a treatment that remains in the relatively early stages of application in baseball.

Dr. Steve Yoon at the Kerlan-Jobe Orthopaedic Clinic in California oversaw a procedure in which bone marrow was extracted from Pomeranz’s hip bone and back. That material was spun down into a stem cell concentrate and injected into the flexor tendon. While the initial removal of marrow wasn’t terribly uncomfortable, the injection was.


“It was pretty painful, to be honest,” said Pomeranz, who exited a start on Sunday with what the Red Sox described as triceps tightness unrelated to last year’s health issues. “The way they do it is they kind of scrape the tendon, the flexor, to create some bleeding I guess, and then they shoot the stem cells on top so I guess your body knows to heal there. I was fine five minutes into it, then about 20 minutes later I couldn’t bend my arm for, like, five days.”

Still, that blip of discomfort was a small price to pay for the possibility of regenerative treatment. Pitchers constantly deal with slight tears of their tendons, with many pitching through them for years until they grow to a point where it is impossible to pitch without surgery.

With a stem cell injection, doctors hoped not merely to signal to Pomeranz’s body that it should heal any damage to the flexor tendon but also used his own cells to promote that healing — to help reverse some of the wear and tear.


Pomeranz had become intrigued with the procedure in 2016, when he heard about Angels pitchers Garrett Richards and Andrew Heaney receiving stem cell treatments rather than undergoing Tommy John surgery after they’d both been diagnosed with partial tears of their ulnar collateral ligaments.

Rest and the stem cell treatment didn’t show enough progress for Heaney to keep him from surgery last fall, but Richards is back on the mound this spring, pumping mid- to upper-90s gas. The idea that Pomeranz might use something in his own body to take a proactive approach to his elbow’s health made sense to the pitcher.

“It’s almost like a cure-all for everything,” Pomeranz said. “Everything I read said that it’s not going to hurt you. It’s only going to help you. Worst case, it will do nothing.

“I think it’s going to be the next new wave of things that you try.”

Results aren’t definitive

Pomeranz is not alone in viewing stem cells as part of a “new wave.” Within the field of sports medicine, orthopedists are eager to find forms of treatment that can reduce the number of surgeries and shorten the amount of time that players miss. Over the last decade, platelet-rich plasma injections had gained increasingly widespread use as a means of promoting accelerated healing, but stem cells represent a potential next step.

“If you look at the practice of sports medicine, we’ve spent the last 30 years learning how to rebuild and reconstruct different body parts, whether it’s the ulnar collateral ligament with Tommy John surgery, ACL surgery, all of those reconstructive procedures that we’ve worked on,” said Dr. Lyle Cain of the Andrews Sports Medicine & Orthopedic Center in Birmingham, Ala.


But the rehab protocols from surgeries, Cain noted, are often measured in years. Sports medicine wants to find biologic solutions that can either prevent or treat injuries, with stem cells representing a particularly intriguing avenue.

“The idea is that if you have an injury to maybe a tendon — like the Tommy John tendon in the elbow or the rotator cuff tendon — and you aren’t at the point where it’s completely detached or it’s bad enough to have surgery but it’s painful, the biologic methods such as stem cells are ways to encourage a healing response in the body,” Cain said.

“The body in those areas has a very poor natural healing response. Tendons can be partially torn for years and never receive the signal from the body to start the healing process.

“Stem cells are a way to try to deliver the chemicals to cells and the chemical attractive factors to that area to allow the body to heal that tissue. That’s what PRP was used for as well. Stem cells have more promise because not only do they have the chemicals that platelet-rich plasma has, but you’re also putting some of the healing cells themselves in that area.”


The first known case of a stem cell treatment by a baseball player came when Bartolo Colon received injections in his injured rotator cuff and elbow after the pitcher missed the 2010 season. That procedure, which took place in the Dominican Republic, eventually drew scrutiny from Major League Baseball based on the advocacy by his doctor of the use of HGH in stem cell treatments for nonathletes.

Nonetheless, the results were noteworthy. Colon resurrected his career with the Yankees in 2011 and has been pitching in big league rotations ever since. (Colon was, however, suspended 50 games for a positive test for testosterone in 2012.)

Dr. Gary Green of Major League Baseball said that the use of stem cells to treat injured players has seen a rise over the last four to five years, particularly in the last year. Green estimated that the number of players treated with stem cells is in the dozens, though he cautioned that it’s difficult to determine their effectiveness.

The theory of how they can work is obvious: If a body’s own tissue can be used in an injured area for regenerative purposes, lengthy absences due to surgery and rehab might be avoided. But right now, the results are anything but definitive.

“Stem cells are completely experimental right now,” said former Red Sox trainer Mike Reinold. “We’re not 100 percent sure right now how effective they are.”

After all, it is possible that the rest and rehabilitation protocols that accompany stem cell treatments are chiefly responsible for the improvement in injured players.


“We’re doing lots of other things in order to help their rehabilitation,” Green said. “Is it getting better because of the stem cells? Is it getting better because of the rehab? It’s a little hard to do that kind of study and isolate one particular thing because players aren’t doing just one particular thing.”

Biologic breakthrough?

Good studies comparing pitchers treated with stem cells against a control population haven’t been possible given that (a) the sample of pitchers is extremely small and (b) players aren’t exactly eager to volunteer to be in a control group in the interests of science. Still, over time, as more and more players like Pomeranz become interested in such procedures, growing case registries may offer better indications of what specific injuries and populations respond well to stem cells.

That said, for players who are considering stem cell treatment in the hopes that it will help them avoid major surgery, there is risk associated with the uncertain outcomes. If a player doesn’t respond to the stem cells, he may have delayed the surgery by months and thus pushed back his timetable for a return.

“People obviously want to find something that will get people back quicker, but you look at the average Tommy John surgery, it’s 14-18 months,” said Green. “If you can get something quicker, that would obviously be good.

“However, let’s say you try a non-operative procedure and it takes six months to know whether it works or not, and then they do need surgery, then you lost six extra months and extended their time away.”

Yet the upside of returning to the field is what will tantalize players — and over time, the incentives may become even greater. For now, the US Food and Drug Administration bans the manipulation of stem cells or the addition of growth factors (such as HGH), measures that are permitted in some other countries, and Major League Baseball requires that any stem cell treatments received by its players follow FDA protocols.

Players can only have their own unaltered stem cells used. In the future, there’s a chance that might change, with genetic modification potentially offering even more significant benefits.

“I think ultimately that’s probably going to happen,” Cain said. “And I think it will become, policy-wise, professional sports will have to decide how to manage this. That’s ultimately where we’re headed.

“The introduction of stem cells in the US probably really started the biologic era in sports medicine.

“I think it’s fascinating. It’s really exciting. We feel like in a lot of ways we’ve somewhat conquered the reconstruction options and the rebuilding options. I think it’s really exciting that we’re on the edge of the frontier of being able to prevent injuries or prevent damage within joints.

“I think it’ll really change the way we practice medicine in the next 15-20 years.”

Given the devastating toll of injuries — particularly on the careers of pitchers — the baseball world can barely mask its enthusiasm about the possibility of a biologics breakthrough in injury recovery.

“That’s at the root of playing or not, right?” said Red Sox manager John Farrell. “If it’s not an HGH chemical, then how can we [regenerate tissue] naturally?

“I think we’re probably just starting to scratch the surface of what might be down the road. But it is really intriguing. It has the potential to save careers.”

It may prove impossible to discern what impact, if any, Pomeranz’s treatment has. But if he enjoys health and success in 2017, then the number of pitchers who express interest in a nascent field will grow.

“The more guys hear about it, the more guys hear about the fact that it works, I think you’re going to see a lot more guys trying it as an alternative,” Pomeranz said.

Source: Dr. Lyle Cain/Andrews Sports Medicine & Orthopedic CenterTonia Cowan/Globe Staff

Correction: Because of a reporter’s error, an earlier version of this story incorrectly identified Dr. Gary Green of Major League Baseball’s first name.

Follow Alex Speier on Twitter at @alexspeier.