Arthroscopic ACL Surgery – Safe & Advanced Treatment for Knee Ligament Injury What is ACL? ACL (Anterior Cruciate Ligament) is a strong ligament inside the knee that helps keep the joint stable during walking, running, and sports activities. An ACL injury usually happens during:• Sports (football, cricket, badminton, basketball)• Sudden twisting injury of the knee• Road traffic accidents• Falls When the ACL is torn, the knee becomes unstable, swollen and painful. There is a sense of giving way.