It's the cutting edge of sports medicine: A patient's own blood, condensed into a healing solution, is used to speed recovery and cure chronic ailments.
World champion figure skater Patrick Chan recently received the treatment, known as platelet-rich plasma therapy, to hasten the recovery of his injured calf. Pittsburgh Steelers stars Hines Ward and Troy Polamalu had it before winning the Super Bowl. And now a growing number of weekend warriors with injured tendons and ligaments are seeking out the procedure.
Experts in sports medicine say that if the treatment's promise is fulfilled, it could accelerate the healing of common injuries such as tennis elbow and tendinitis in athletes at all levels.
The process involves injecting a patient's specially prepared blood into an injured tendon, muscle or ligament. The injected material - a concentrated solution of platelets, which contain growth factors - triggers the body's ability to repair muscle, bone and other tissue.
For elite athletes, the greatest benefit may be quicker recovery times. But doctors say the relatively simple procedure is most promising for chronic ailments commonly suffered by recreational athletes, such as tendinitis of the elbow, knee or Achilles tendon.
"The patients I treat have failed other treatments - failed physical therapy, anti-inflammatory medication - and are up against surgery as their only option," says Allan Mishra, an assistant professor of orthopedics at Stanford University and one of the primary researchers in the field.
Platelet-rich plasma has been used in some types of plastic surgery since the early 1990s, but its use in sports medicine has spiked in recent years, partly because of the treatment of some high-profile elite and professional athletes.
Tony Galea, a sports physician in Toronto, began offering the treatment eight years ago, when its application in sports medicine was in its infancy. Among his patients are Tiger Woods, NFL stars and Mr. Chan, Dr. Galea says. But about 40 per cent of his patients are people just staying active by swimming, jogging or playing recreational sports.
"They're in quite good shape for their age," Dr. Galea said in an interview, "but they do a lot of things and they get hurt doing them."
The procedure is not covered by provincial health insurance, so his patients pay $500 for each injection. Depending on the injury, they may need more than one.
Last week, a presentation by Dr. Galea hosted by the University of Toronto drew dozens of sports doctors, physiotherapists and medical students interested in the procedure.
(News had broken a day earlier that Dr. Galea's offices had been raided by the RCMP. He has since been charged with illegally importing and selling drugs. Dr. Galea's lawyer said the charges are based on false information about the homeopathic remedies in question, which are not related to platelet-rich plasma).
Describing the healing benefits of blood, Dr. Galea told the U of T audience: "There is no pharmaceutical company that can spend tens of millions of dollars to recreate such a beautiful formula for health."
But he also emphasized that more large clinical trials are needed. "We're at the Wild West of this type of tissue engineering," he said.
While several doctors interviewed for this story heralded the potential of PRP, they also emphasized that there are still many unanswered questions, including how effective it is for treating acute injuries.
While research has accelerated in recent years, procedures - such as how often the treatment should be administered, how that should be done - have not been clearly defined through large clinical trials.
"There's very little data on how you do this," said Robert Monaco, the Rutgers University team physician and a clinical associate at Robert Wood Johnson medical school, where he conducts research on PRP. "I think there is some data to say that it is working. But the exact nature of the techniques and how to handle rehabilitation afterwards are not clear."
Dr. Monaco, who also teaches a course for clinicians on the proper use of PRP, says he's worried that some practitioners are leaping too far ahead of the science. While there seems to be little risk of harming the patient, poorly administered care could make the treatment ineffective.
For example, he said, he is always guided by ultrasound images when he injects the platelet-rich solution to make sure he hits the injured area. Patients should avoid clinicians who go in blindly. "I think some people are using it inappropriately, and it's gong to be abused. It's a problem."
The point was highlighted in a review article published earlier this year in the Journal of the American Academy of Orthopedic Surgeons.
"Many controlled clinical trials are under way, but clinical use should be approached cautiously until high-level evidence supporting platelet-rich plasma efficacy is available," the authors wrote.
Of course, in elite sports, time is money - and even without solid research top athletes have embraced treatments that can get them back on the playing field even one week sooner. (Experts say PRP is not a quick fix, however: When combined with regular physiotherapy, it can help get athletes back in action within weeks, depending on the type of injury.)
But many sports medicine experts point out that if PRP continues to be found safe and effective, the greatest benefits will be for those who use sports for recreation and fitness. "That's the area where the evidence is the best," Prof. Mishra says.
In those cases, the treatment could help heal painful injuries that have hampered the person's ability to exercise and simply have fun.
"A weekend warrior who's had six months of tennis elbow or plantar fasciitis ... wants treatment which affords an opportunity for lesions to heal," said Andrew Pipe, medical director at the University of Ottawa Heart Institute, who has been physician for the national men's basketball team and served as Canada's chief medical officer at the 1992 Olympic Games in Barcelona.
"If you can get a chronic [injury]to heal without surgery, then that's a good thing."