CHICAGO (AFP) -- U.S. researchers have devised a new technique to help repair torn or ruptured knee ligaments, a common type of sports injury, a study said.

In preliminary studies, the investigators were able to engineer new tissue in the damaged ligaments of rabbits in just 12 weeks. The hope is that if the approach works in humans, it could accelerate recovery times.

The researchers used a synthetic scaffold seeded with ligament cells to regenerate the new tissue in the damaged anterior cruciate ligament of rabbits.

The bunnies were able to begin bearing weight on their knees 24 hours after surgery, and by the end of the 12-week experiment, the animals had fresh collagen and blood vessels growing in the damaged area.

"It is my hope that these studies will lead to a revolutionary new treatment strategy for patients suffering from ACL tears," said Cato Laurencin, a professor of orthopaedic surgery and biomedical engineering at the University of Virginia in Charlottesville who lead the study.

The anterior cruciate ligament is the stabilizing ligament that connects the thighbone to the legbone.

It unravels like a braid when ruptured, making healing difficult.

In humans, the standard treatment for this problem is reconstructive surgery. Surgeons remove healthy tissue from tendons around the knee and graft it onto the damaged ligament in order to regenerate it.

But it can take five to six months for a full recovery, and surgeons would prefer not to harvest healthy tissue if at all possible.

Researchers have tried to craft ligament-like scaffolds to help the healing process before, but success has been limited.

This is the first time that researchers have combined synthetic materials with ACL cells and been able to substantially engineer new ligament tissue.

In addition to the "biomimetic" scaffold, which combined synthetic materials with animal cells, the researchers also tested a purely synthetic scaffold, but the healing process seen with this device was slower.

Further tests will be required to determine the value of this approach, but the results of this preliminary study indicate it could be a promising ligament replacement therapy, which could potentially speed up the recovery process, Laurencin said.