1. Department of Neurosurgery, Szpital sw. Rafala in Cracow, Cracow, Poland
2. Collegium Medicum, WSB University, Dabrowa Gornicza, Poland
3. Department of Orthopedic, Szpital Powiatowy w Zawierciu, Zawiercie, Poland
4. Department of Neurosurgery, 5th Military Clinical Hospital with the SP ZOZ Polyclinic in Krakow, Krakow, Poland
5. Department of Neurosurgery, Faculty of Medicine in Zabrze, Academy of Silesia, Katowice, Poland
6. Department of Neurosurgery, Faculty of Medicine and Health Sciences, Andrzej Frycz Modrzewski University in Cracow, Cracow, Poland
7. Institute of Health Care, National Academy of Applied Sciences in Przemyśl, Przemyśl, Poland
8. Department of Medical Science, New Medical Techniques Specialist Hospital of St. Family in Rudna Mała, Rzeszów, Poland