Knee ligament repair/reconstruction is a surgical procedure performed to restore the stability and function of a damaged or torn knee ligament, such as the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), or lateral collateral ligament (LCL). The surgery involves repairing the damaged ligament or replacing it with a graft, which can be taken from the patient's own body or from a donor.