David R. Campbell, MD, FAAOS, is an orthopedic surgeon practicing in Florida and was an assistant professor of orthopedic surgery in the College of Medicine at the University of Central Florida. He is a retired major in the United States Army Reserve Medical Corps and author of The Teen Formula: A Parent's Guide to Helping Your Child Avoid Substance Abuse. A graduate of Columbia College and the University of Miami School of Medicine, he has been the chief medical correspondent for MSNBC's Morning Joe and a medical contributor for MSNBC and NBC.