1. Australian Orthopaedic Research Group, Melbourne, Australia
2. Department of Orthopaedic Surgery, St. Joseph's University Medical Center, Paterson, NJ, USA
3. Southern California Hip Institute, North Hollywood, CA, USA
4. MultiCare Orthopedics & Sports Medicine, Auburn, WA, USA
5. Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA