Golfer Tiger Woods, above, and Kenyon Martin of the Denver Nuggets, below, have
both been treated with platelet-rich plasma taken from their own blood and inserted
into the site of their sports injuries.
Seattle Mariners pitcher Cliff Lee used it for an abdominal strain. Denver Nuggets power forward Kenyon Martin used it on a strained left knee. Last year, Tiger Woods had injections of it in his left knee before four majors and Pittsburgh Steelers Troy Polamalu and Hines Ward used it to treat a strained calf and a sprained knee ligament before the team's Super Bowl win.
The treatment, known as platelet-rich plasma, or PRP, is one of a growing number of therapies that enhance the body's ability to heal itself. A physician extracts about one to two ounces of blood from the patient's vein and spins it in a centrifuge to separate out the platelets, the part of the blood that secretes growth factors to promote clotting and healing. The doctor injects that platelet-rich plasma back into the patient at the site of injury, where it spurs the repair of injured tissue. Most patients experience relief within several weeks.
ScienceDaily (Oct. 22, 2009)
Damaged knee joints might one day be repaired with cartilage grown from stem cells in a laboratory, based on research by Professor Kyriacos Athanasiou, chair of the UC Davis Department of Biomedical Engineering and his colleagues.
Using adult stem cells from bone marrow and skin as well as human embryonic stem cells, Athanasiou and his group have already grown cartilage tissue in the lab. Now they are experimenting with various chemical and mechanical stimuli to improve its properties.
Cartilage is one of the very rare tissues that lacks the ability to heal itself. When damaged by injury or osteoarthritis, the effects can be long-lasting and devastating.
"If I cut a tiny line on articular cartilage (the cartilage that covers the surfaces of bones at joints), it will never be erased," Athanasiou said. "It's like writing on the moon. If I go back to look at it a year later, it will look exactly the same."
Work that Athanasiou's group began in the early 1990s at Rice University has resulted in the only FDA-approved products for treatment of small lesions on articular cartilage. (In total, Athanaisou's patents have resulted in 15 FDA-approved products.)
"This will be live, biological cartilage that will not only fill defects, but will potentially be able to resurface the entire surface of joints that have been destroyed by osteoarthritis," Athanasiou said. Currently, joint replacements using metal and plastic prosthetics are the only recourse for the one in five adults who will suffer major joint damage from osteoarthritis.