Over the past four years there has been a resurgence in interest about a small little lateral ligament of the knee known as the anterolateral ligament (ALL). I’m not even sure I remember learning much about it during school, but with the number of ACL reconstructions associated with chronic rotational instability rising, researchers and surgeons have been diverting focus to understand what impact an ALL-deficient knee has on ACL recovery and regaining rotational stability. This blog is a refresher about the anatomy and biomechanical function of the ALL and what we currently know to be true about it’s role in rotational stability of the knee.