1. Kerlan-Jobe Orthopaedic Institute, Los Angeles, California, USA
2. American Hip Institute Research Foundation, Chicago, Illinois, USA
3. American Hip Institute, Chicago, Illinois, USA
4. AMITA Health St Alexius Medical Center, Hoffman Estates, Illinois, USA
5. Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA
6. Department of Orthopedic Surgery, Mayo Clinic, Phoenix, Arizona, USA
7. Andrews Sports Medicine and Orthopaedic Center, Birmingham, Alabama, USA