Menu Healthy Lifestyle Diseases & Conditions First Aid Symptoms Tests & Procedures Videos Definitions FAQs Anterior cruciate ligament injuryUpdated: 2017-06-13OverviewAnterior cruciate ligament (ACL) injury is a tear in the ACL, tissue that connects the thighbone to the shinbone, at the knee. Most ACL injuries occur during certain sports such as basketball, soccer, and tennis.SymptomsSymptoms include knee swelling, instability, and pain when standing.TreatmentsTreatment may include surgery and physical therapy. © 1998-2022 Mayo Foundation for Medical Education and Research(MFMER). All rights reserved. Terms of Use