Anterior cruciate ligament reconstruction (ACL reconstruction) is a surgical tissue graft replacement of the anterior cruciate ligament, located in the knee, to restore its function after anterior cruciate ligament injury. The torn ligament is removed from the knee before the graft is inserted through a hole created by a single hole punch. The surgery is performed arthroscopically. An ACL reconstruction is sometimes referred to, incorrectly, as an ACL repair. A torn anterior cruciate ligament cannot be "repaired", and must instead be reconstructed with a tissue graft replacement.