[Postoperative knee : Tips and pitfalls for the interpretation of ACL surgery]

The anterior cruciate ligament (ACL) is the most important restraint against anterior tibial subluxation and provides stability in flexion, extension and internal rotation as well as varus and valgus stress. Certain sports activities, such as soccer, rugby, skiing, and dancing increase the risk of ACL injuries. The decision for surgical treatment is primarily clinically based under consideration of multiple factors, such as age, body habitus, gender and specific physical activities. There are numerous different techniques for ACL reconstruction each with advantages and disadvantages. The radiologist and the clinician should be familiar with the different appearances of ACL grafts on postoperative imaging depending on the time interval between arthroscopy and imaging. This article reviews the anatomy of the ACL and the most common ACL reconstruction techniques and discusses the normal postoperative findings and complications of ACL reconstruction based on different imaging techniques.