Received: 11 February 2019
Accepted: 28 May 2019
First Online: 11 June 2019
Ethics approval and consent to participate
: This retrospective clinical study was approved by the Local Ethics Committee of the Otto-von-Guericke University Hospital, Magdeburg, in accordance with the Declaration of Helsinki. All participants provided written informed consent to analysis and publication of anonymized data before surgery took place.
: Not applicable.
: The authors declare that they have no competing interests.