1. Department of Pediatric Orthopedic Surgery and Traumatology, Medical University of Bialystok Children’s Clinical Hospital, Waszyngtona 17, 15-274 Bialystok, Poland
2. Paley European Institute, Al. Rzeczypospolitej 1, 02-972 Warsaw, Poland
3. Medical Faculty, Medical University of Warsaw, 02-091 Warsaw, Poland
4. Department of Neurosurgery, University of North Carolina, Chapel Hill, NC 27516, USA
5. 2nd Clinical Department of General and Gastroenterogical Surgery, Medical University of Bialystok Clinical Hospital, ul. M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland