1Department of Orthopaedic Surgery, University of Southern California, 1200 N. State St., GNH 3900, Los Angeles, CA 90033, USA
2Keck School of Medicine, University of Southern California, 1975 Zonal Avenue, Los Angeles, CA 90089, USA
3Division of Orthopedics, Department of Surgery, Cedars Sinai Medical Center, 444 S. San Vicente Blvd., Ste. 603, Los Angeles, CA 90048, USA
4Department of Orthopaedics, University of Southern California, 1520 San Pablo Street, Suite 2000, Los Angeles, CA 90033, USA