1 Dartmouth College, Geisel School of Medicine, Hanover, New Hampshire, USA. Electronic address: chad.y.lewis@dartmouth.edu.
2 17th Surgeon General of the United States, University of Arizona, Tucson, Arizona, USA. Electronic address: pmaxwell@canyonranch.com.
3 Department of Orthopaedic Surgery, University of Louisville, School of Medicine, Louisville, Kentucky, USA. Electronic address: craig.roberts@louisville.edu.