Tiger Woods, Rafael Nadal and Hines Ward turned to it. It carries minimal risk and may ease pain without invasive procedures or drugs.

Platelet rich plasma therapy is catching the attention of pro athletes and ordinary people whose orthopedic injuries haven't been cured by traditional treatments such as surgery or steroids.

With PRP treatments, a small amount of a patient's own blood is spun in a centrifuge, creating up to a 500 percent concentration of platelets.

Those platelets are then injected into the injured site. Because platelets release growth factors, they're thought to speed the repair of wounded tissue.

"It just makes sense," said Dr. Anne Truong of Truong Rehabilitation Center, the only physician in the area who offers PRP therapy.

Truong said she uses PRP in her Spotsylvania County office primarily to treat tendon and ligament injuries. She's been using PRP therapy for two years and is so confident in the procedure that she has treated her co-workers, her husband and herself with PRP. Truong said she had a torn meniscus--a cartilage injury--in her knee that she treated with PRP.

"I know how the kind of pain my patients feel is," Truong said. "My PA [physician assistant] injected me, and it helped. I returned to work the next day."

Truong predicts that PRP treatments will eventually replace surgery as the primary treatment for many injuries. But more research is needed to verify the therapy's effectiveness. So far, the research is limited--and mixed.

LIMITED RESEARCH

In January, the Journal of the American Medical Association published a study reporting that PRP injections are no more effective than saltwater.

People in the study had injuries to the Achilles tendon, which account for 30 percent to 50 percent of all activity-related injuries.

Compared to those injected with saline, the PRP group did not show any significant improvement in pain and activity.

But another study, published by the American Journal of Sports Medicine in February, reported improvement in patients with tennis elbow who were treated with PRP.

The control group, injected with steroids, did not have the lasting effects that PRP patients did, researchers found. The condition of the control group's joints deteriorated, while the PRP patients continued to improve.