Manuel Lanzini from Argentina’s national team tore his anterior cruciate ligament (ACL) during practice on June 8, 2018.

The ACL runs through the center of the knee joint. It stabilizes the knee when a player plants the foot and turns.  That maneuver is often referred to “pivoting.” One forceful pivot can tear the ligament.  This is one of the few ligaments in the body that don’t heal when they rupture.

There is often a pop that is heard or felt.  The knee usually fills with blood and the effusion can be detected on examination.  Specific examination techniques can look for the greater laxity that tends to occur after ACL rupture.  Because pain and guarding may mask that exam, and an x-ray only shows fractures, an MRI is typically used to confirm ACL tear. The MRI might also show injury to other ligament, the meniscus, or bone.  That information would mostly affect prognosis.

ACL tears are nearly always complete.  The body cannot heal an ACL tear.  The first step is to regain motion in the knee.  That usually takes a few weeks of stretching.  People with ACL tears are offered surgery to reconstruct the ACL with a tendon or ligament taken from another part of the body or from a tissue bank is offered.  High-level athletes in sports with a lot of pivoting usually choose surgery if they want to their sport. People that do very little pivoting or who are willing to limit those activities often choose to leave the ACL unrepaired.

Lanzini will have surgery to reconstruct the ACL.  Return to play takes about a year, because the graft needs to be solidly healed and the muscles strong in order to limit the risk of reinjuring.

This blog was written by Paul Bonilla and David Ring.