1. Department of Pediatric Orthopedic Surgery and Traumatology, University Children’s Hospital, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland
2. Paley European Institute, Al. Rzeczypospolitej 1, 02-972 Warsaw, Poland
3. Department of Orthopaedic Surgery, Washington University in St. Louis, 660 S. Euclid Ave., St. Louis, MO 63110, USA
4. Paediatric Orthopaedic Department, Medical University of Lublin, Gebali 6, 20-093 Lublin, Poland
5. Department of Spine Disorders and Pediatric Orthopaedics, Poznań University of Medical Sciences, 28 Czerwca 1956 r. Street, No. 135/147, 61-545 Poznań, Poland
6. 2nd Clinical Department of General and Gastroenterogical Surgery, The Medical University of Bialystok Clinical Hospital, Medical University of Bialystok, M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland