1. Division of Pediatric Orthopaedic Surgery Department of Orthopaedic Surgery Columbia University Irving Medical Center New York New York USA
2. Department of Epidemiology Mailman School of Public Health Columbia University New York New York USA
3. Department of Orthopaedic Surgery University Hospital Cleveland Medical Center Rainbow Babies and Children’s Hospital Cleveland Ohio USA
4. Spine Center Cedars‐Sinai Medical Center Los Angeles California USA
5. Division of Orthopaedic Surgery Children’s Hospital of Philadelphia Philadelphia Philadelphia USA
6. Department of Orthopaedic Surgery The Johns Hopkins University Baltimore Maryland USA
7. Bloomberg Children’s Center Baltimore Maryland USA