1Department of Orthopaedic Surgery, Midwest Orthopaedics at Rush, Rush University Medical Center, 1611 W. Harrison St., Suite 300, Chicago, IL 60612, USA
2Department of Orthopaedic Surgery, Carolina Medical Center, OrthoCarolina Foot and Ankle Institute, 2001 Vail Ave., Suite 200 B, Charlotte, NC 28207, USA