Traumatic Central Disc Herniation By Troy Freiheit, DC Dr. Troy Freiheit, a 1987 graduate of Northwestern Health Sciences University, operates private practices in Scottsdale and Phoenix, Ariz. He is also the founder of continuing-education provider PI Pro; for more information, contact Troy at . Page printed from: https://www.dcpracticeinsights.com/mpacms/dc/article.php?id=59434&MERCURYSID=80fd2d89298330a695a9cc8714de71e3&no_paginate=true&p_friendly=true&no_b=true