Yeah, my ortho said it's only a relatively new discovery and there's still disagreement amongst his colleagues. They are looking at why there's been an increase of ACL injuries recently and micro-damage is one hypothesis.I’m highly skeptical of this being the case (Barring some sort of genetic defect).
There’s very strong evidence that ligaments (with research done specifically on the ACL) positively adapt to load.
Effects of season long participation on ACL volume in female intercollegiate soccer athletes
The aim of this study was to characterize the volumetric changes of the anterior cruciate ligament over the course of a competitive soccer season in female athletes.Seventeen Division-I collegiate soccer players were recruited. Two data collection sessions ...www.ncbi.nlm.nih.gov