Indianapolis Colts star quarterback Peyton Manning is the most recent pro athlete to look into having his injuries treated using stem cell procedures, which are widely regarded as the future of sports medicine.

Jay Bilas, of FOX Sports, reported on Sept. 18 that Manning flew to an unidentified European country to investigate whether stem cells would heal his

ailing neck.

In doing so he was following the lead of New York Yankee pitcher Bartolo Colon, who underwent injection of stem cells in 2010 to repair torn connective tissue in his pitching shoulder. Colon, who has returned to baseball this year at the age of 38,   has posted a respectable record of 8-10.

“Early on, there was a concern [about using stem cells],” said Dr. Rick Lehman, medical director of the U.S. Center for Sports Medicine. “Truth of the matter is, we are far enough down the line andwe understand [and] we don’t see a lot of negatives. We got enough under our belt now were we are confident in using them.”

Dr. Lehman has been injecting pro-college athletes with stem cells for about three years now and said he and his staff are seeing enhanced healing they have never seen before. The healing process is faster with the stem cell procedure, he said.

According to Lehman, a “Tommy John procedure” done to pitchers, who have injured their collateral ligament—which is one of the four ligaments that stabilize the elbow joint—can take up to a year to heal, but he said with stem cell injections, the players are throwing four months later and are at full strength by the sixth month. Lehman also said it makes repaired injuries stronger.

According to the Institute of Regenerative and Molecular Orthopedics in Boca Raton, Fla., stem cells are the “repairmen” of the body. Mesenchymal cells, which are adult stem cells, are most often seen in research associated with tissue repair. These cells travel through the blood stream to the injured area. If the area of the injury has poor blood supply, it is an area of hypoxia, or low oxygen content and means it will not heal on its own.

Joseph R. Purita, an orthopedic surgeon who runs the regenerative medicine practice in Boca Raton, used fat and bone marrow stem cells from Colon and he injected the stem cells into the pitcher.

Dr. Lehman said initially there was a high percentage of fatty stem cells. Normally, he and his team harvest them by withdrawing them from fat, bone marrow or an A-Cell that has been nurtured from a pig. The A-Cell provides an unlimited supply, he said.

“In an athlete who is planning on attending the Olympics, we [should not] stick needles in their bone or in their stomach [when] the A-Cell is readily available.”

Lehman said,“These cells are immature [at first]. As they mature, they can be anything you want them to be. If you inject them in the rotator cuff, they will become collagen cells.”

Colon was a dominant pitcher between 1998 and 2005. During that time, he had 10 or more wins in each season while having two 20-win seasons. Colon has not completed an entire season since the 2005 campaign because he struggled with injuries and was kept out of the entire 2010 season after elbow surgery.