Received: 10 March 2018
Accepted: 14 March 2018
First Online: 20 March 2018
: All authors are part of the SarKUM, the Bone and Soft Tissue Tumor Center of the University Hospital, Ludwig-Maximilians-University Munich.
: This study was approved by the ethics committee of the Medical Faculty, University of Munich. Written consent was obtained from all surviving patients included in this study. In accordance with the ethics committee, the data from non-surviving patients were irreversible anonymized for statistical evaluation.
: Not applicable.
: The authors declare that they have no competing interests.
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