The complications of ACL reconstruction include:Graft failure, which involves tearing of the graft used to repair the injured ACL. This occurs in 6%of the patients.Numbness on the outside of the upper leg, near the surgical cuts. This is a common complication, which can be temporary or permanent.Unstable knee joint when the graft stretches or tears.Permanent stiffness or less movement than before.Long-term knee pain or pain while kneeling.