1. Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Hip Preservation Center, Chicago, IL, USA
2. Department of Orthopedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, Rhode Island, USA
3. The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
4. Department of Orthopedic Surgery, MedStar Union Memorial Hospital, Baltimore, Maryland, USA