Two knee surgeons have identified a previously unknown ligament in the human knee. The discovery could have important ramifications for patients who experience anterior cruciate ligament (ACL) injury.

“Despite a successful ACL repair surgery and rehabilitation, some patients with ACL-repaired knees continue to experience so-called pivot shift, or episodes where the knee gives way during activity,” according to a press release from University Hospitals Leuven, Belgium.

The doctors are the first to identify the previously unknown ligament after a broad cadaver study using macroscopic dissection techniques, the press release noted. “Their research shows that the ligament, which was given the name anterolateral ligament (ALL), is present in 97 per cent of all human knees.”

Their research shows that pivot shift, the giving way of the knee in patients with an ACL tear, is caused by an injury in the ALL ligament.

?Some of the conclusions were recently published in the Journal of Anatomy.