Received: 27 June 2017
Accepted: 29 November 2017
First Online: 17 January 2018
Ethics approval and consent to participate
: The institutional review board of the University of Heidelberg approved all procedures of this study (S-546/2013). Written consent was obtained from all patients included in this study.
: Not applicable
: TG and TW received payment from Zimmer Biomet as a Principal Investigator outside of this submitted work.
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