Inclusion Criteria:  Patients who underwent ACL reconstruction with single-bundle anatomical technique (patellar tendon, semitendinous and gracile tendons) or "Over-The-Top plus lateral plastic" technique and any associated procedures with at least 15 years of follow up; Patients aged between 15 and 50 at the time of surgery; Patients with isolated ACL tear; Patients with healthy contralateral knee at the time of surgery.  Exclusion Criteria:  Patients with grade III-IV chondral lesions according to Outerbridge scale at surgery; Patients no longer available; Women of childbearing age who cannot exclude pregnancy; Patients unable to give informed consent or patients unwilling to sign informed consent.