Every year, an estimated 250,000 people, most of them young, tear their ACL.

For a high percentage of them, traditional surgery won't restore full mobility or delay the onset of osteoarthritis.

But there may be a new option.

Doctors at the University of Pennsylvania Medical Center started looking at ways to improve the surgery six years ago.

The ACL connects the thigh bone to the shin bone in the middle of the knee joint.

Minimally invasive arthroscopic surgery is used to repair a torn ACL, but orthopedic surgeon Dr. Freddie Fu says he's found a way to improve it.

“What we do [now] is single bundle surgery — we use a one size fits all kind of surgery,” said Dr. Fu. “But right now we try to fine tune it so this technique will provide better rotational control."

Dr. Fu's "double bundle reconstruction" surgery uses two small grafts instead of one big one.

The long term results of the new procedure are still pending.