The ACL (anterior cruciate ligament) is the ligament located on the inside, front part of the knee. It is notably one of the most injured ligaments among athletes and can occur in isolation or with another ligament. There are 3 main ligaments or groups of ligaments aside from the ACL that support the knee, the PCL (posterior cruciate ligament), LCL (lateral collateral ligament) and MCL (medial collateral ligament). If one or more of these ligaments are torn during the injury, early reconstruction of all torn ligaments is recommended, approximately 3 weeks after injury. Often, donor tendons have to be used as grafts to adequately reconstruct all of the ligaments. Arthroscopy is also performed to assist in the reconstruction and address any concomitant injury to the meniscus or cartilage. Your physician will discuss graft options with you and his proposed surgical plan. The rehabilitation for these multiple ligament injuries is complex and controlled to protect and stabilize the knee while the reconstructed ligaments heal. Your physician and physical therapist will guide you along the way through the rehabilitation protocol. Following this thorough rehabilitation program as directed by your physician, patients are usually able to resume most normal activities within 6-9 months following surgery , and are usually unrestricted after 12 months.