[1] Med Univ Bialystok, Dept Pediat Orthoped Surg & Traumatol, Ul Waszyngtona 17, PL-15274 Bialystok, Poland
[2] Med Univ Bialystok, Childrens Clin Hosp, Ul Waszyngtona 17, PL-15274 Bialystok, Poland
[3] Paley European Inst, Al Rzeczypospolitej 1, PL-02972 Warsaw, Poland
[4] Med Univ Bialystok, Dept Neurosurg, Dept Intervent Neurol, ul M Sklodowskiej Curie 24A, PL-15276 Bialystok, Poland
[5] Med Univ Bialystok, Clin Hosp, ul M Sklodowskiej Curie 24A, PL-15276 Bialystok, Poland
[6] Univ N Carolina, Dept Neurosurg, Chapel Hill, NC 27516 USA
[7] Med Univ Bialystok, Clin Dept Gen & Gastroenter Surg 2, Ul M Sklodowskiej Curie 24a, PL-15276 Bialystok, Poland
[8] Washington Univ, Sch Med, Dept Orthoped Surg, 660 S Euclid Ave, St Louis, MO 63110 USA