A new research has cast doubt on blood-based injections reportedly used by Tiger Woods and other athletes to speed up recovery after orthopedic surgery.

A small scale study conducted at a hospital in The Netherlands, the treatment did not work better than salt water injections in patients with overuse Achilles tendon injuries.

Achilles is the longest tendon in the body which connects calf muscles in the lower leg to the heel bone and it is prone to overuse injury from sports including running.

The treatment involves injections of platelet-rich plasma, or PRP, extracted from patients’ own blood.

Platelets are a component of the blood and help in blood-clotting as they release growth-promoting substances which help in repairing damaged tissue.

The legendary golfer, Tiger Woods, is reported to have had these injections after June 2008 knee surgery.

The study involved 27 adult patients who got PRP injections and 27 others who were administered salt water injections. One week later a three month exercise program was started for patients of both the groups.

Patients from both the groups reported the same amount of improvement in pain and activity levels after six months.

Wednesday’s journal of the American Medical Association will contain the results of this study.