Bartolo Colon (Photo Credit: Flickr @dbfoto via Creative Commons license)

 

Bartolo Colon, a pitcher for the New York Yankees, is at the center of a Major League Baseball (MLB) investigation after he opted for stem cell therapy to treat an elbow and shoulder injury.

MLB wants to know whether such stem cell treatment qualifies as a performance-enhancing drug. If Colon's procedure included a dose of human growth hormone -- which is banned in baseball -- then MLB might have a case. But a New Scientist investigation suggests that the treatment was probably restorative, and does not endow people with "superhuman" powers.

Colon's professional baseball career began impressively. In 2005, he won the American League Cy Young award for best pitcher. However, that season he partially tore the rotator cuff in his pitching arm, a group of muscles and tendons that stabilize the shoulder.

In the years following the injury, Colon's rise faltered. He was sidelined in the final two months of the 2009 season and didn't play at all in 2010. However, after impressive pitching in the 2010 off-season, the Yankees signed the 38-year-old in January this year on a $900,000 contract. Colon is now back in action, pitching at 150 kilometers per hour in MLB games.

What changed? It seems Colon has grown a new tendon thanks to stem cell therapy.

Joseph Purita, an orthopaedic surgeon who runs a regenerative medicine clinic in Boca Raton, Fla., treated the athlete in the Dominican Republic in April 2010. In a 45-minute procedure, Purita says he extracted Colon's stem cells from his bone marrow and fatty tissue and then injected them into his elbow and shoulder to repair the damage -- without using any human growth hormone.

Damon Noto, of the Spine and Joint Center in Hasbrouck Heights, N.J., and the Hackensack University Medical Center performs the surgery Colon received, and explained how the operation works.

First, a tissue sample containing mesenchymal stem cells (MSCs) is extracted from two places in the patient's body: bone marrow and fatty tissue. MSCs have the ability to become bone, fat, cartilage, neurons and connective tissue, among other cells. After centrifuging the extracted sample to isolate the stem cells, they are injected into the site of injury.

This is essentially a more sophisticated version of a treatment that athletes have received since the 1980s called microfracture surgery. In this surgery, holes are drilled into an injured bone, allowing MSCs to seep out and repair the damaged cartilage, bone or tendon.

Exactly what MSCs do is not clear, but there are two main hypotheses: Either the stem cells become new tendon and muscle tissue themselves, or they release growth factors that encourage resident tendon and muscle cells to proliferate at the injured site.

If the MSCs do grow into a new body part, an important question arises: Can they regrow it so effectively that they endow it with enhanced abilities? Colon reportedly says he feels like he has the shoulder of his youth again. Noto is impressed.

"The power of this treatment continues to amaze me," he says. "He had this procedure and within a couple of months he's back to pitching like he did when he was a younger man." Yet Purita says there's no research in people on whether stem cell therapy improves tendon or joint performance beyond pre-injury abilities.

In horses, however, it's a different matter. Roger Smith, of the Royal Veterinary College in North Mymms, Hertfordshire, UK, and colleagues have pioneered stem cell injection therapy for racehorses with injured tendons, and have examined the results.

When horses with tendon injuries receive conventional treatment, between 50 and 60 per cent of the animals re-injure themselves after treatment, Smith says. But when Smith and colleagues tracked the health of 141 racehorses who received stem cell therapy following injury, they found that the rate of re-injury dropped to 27.4 percent.

What's more, the horses showed no signs of tumors, which sometimes develop after treatments with pluripotent embryonic stem cells (Equine Veterinary Journal).

In unpublished research, Smith tested the elasticity of injured horse tendons repaired with MSCs. The data, he says, suggest that the tendons are as elastic as they were before injury, but do not gain superequine powers. If this holds true for people, then Colon's surgery probably restored his rotator cuff to its former glory without granting the athlete any talents he didn't possess before his injuries.

However, Purita is concerned that the procedure could be abused by athletes in the future if it is not used exclusively as a treatment.

"I'm going to suggest to the MLB that we form a committee to regulate this and determine when it's appropriate and when it's not," he says.

 

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