Long-term results after the modified Ravitch procedure performed in children and adolescents – a one-time procedure without the need to use additional support of the sternum. A retrospective study - Buchwald, Joachim; Ligarski, Dariusz; Polewczyk, Tomasz (Kardiochirurgia i Torakochirurgia Polska/Polish Journal of Thoracic and Cardiovascular Surgery, 2020)