A lot is known, a lot is unknown...

摘要

When Jon Karlsson asked us to be the Guests Editors of a KSSTA issue on anterior cruciate ligament (ACL), we thought that the subject would have been not really original and appealing because thousands of studies have previously been published on this topic, since ACL is probably the anatomical part of the knee that has been analysed the most. All the aspects of ACL have been studied, and we guessed that it was quite difficult to find something truly new to present.However, we were totally wrong and while we were approaching the selection of the articles for this special issue, we remembered the words of an ancient Greek philosopher stating "the only true wisdom is in knowing you know nothing." This is totally correct also for what concerns the ACL and during the selection of the articles, we realized that the meaning of those words is still relevant and should always be born in mind when you are involved in scientific research.