What Is the Scientific Basis for Knee Ligament Healing and Maturation to Restore Biomechanical Properties and a Return to Sport?

Abstract

Injury to the anterior cruciate ligament (ACL) can lead to significant dysfunction and instability in athletes. Over the last several decades, a vast body of research has been published on reconstruction techniques to restore knee stability and limit future injury to the meniscus and chondral surfaces of the knee. Overall, satisfactory patient outcomes can be achieved with a high percentage of patients returning to high levels of activity. Despite extensive research on the natural history of ACL injuries, reconstructive techniques, and the biology of healing, there are still many unanswered questions. There are many potential factors for ACL failure and resultant laxity postoperatively. Despite proper patient selection, graft choice, surgical technique, and postoperative rehabilitation, there are still other factors still not completely understood that play a role in a successful patient outcome. The biological phenomenon known as ligamentization and the maturation process that the ACL graft undergoes is complex, intricate, and still a matter of debate. The healing process of the grafted ACL and its ultimate role in restoring normal function of the knee is still not completely understood; however, we aim to summarize the most current evidence to help guide decision-making in eventual safe return to sports (RTS) and activities.