There is a 97% chance that you have a body part you never knew about. Two Belgian knee surgeons have discovered a previously unidentified ligament in the knee that may significantly affect healing from anterior cruciate ligament (ACL) tears.
The surgeons found the ligament buried in layers of muscles and tendons and named it the anterolateral ligament (ALL). They found the ALL while trying to explain a condition called a “pivot shift,” in which knees give out during activity following a successful repair of an ACL injury. They believe the ALL is present in 97% of all human knees.
The surgeons based their search on an 1879 paper written by a French surgeon, which mentioned a “pearly, resistant, fibrous band.” By carefully dissecting the knees of 41 cadavers, they discovered the ligament toward the front and side of the knee, where it connects the femur and the anterolateral tibia.
Their research suggests that damage to the ALL may contribute to instability following ACL repair, and the pair of doctors hope to begin work on devising a method to repair ALLs.