A ruling by the 3rd U.S. Circuit Court of Appeals has opened up the door for personal injury cases involving NFL concussions to now be tried as class action lawsuits. The reason why this is such a big deal is that the U.S. Supreme Court’s landmark 1997 decision in Amchem v. Windsor and its 1999 followup, Ortiz v. Fibreboard, made the use of class actions to settle large swaths of personal…