Received: 26 September 2018
Accepted: 10 July 2019
First Online: 23 July 2019
Ethics approval and consent to participate
: Ethical approval was obtained according to local and national regulations; the need for consent to participate was waived (ethical committee of the canton of Bern, Switzerland).
: Not applicable.
: MJBK is a consultant for Stryker, Depuy Synthes, and Biedermann Motech GmbH & Co. KG. KAS is a consultant for Depuy Synthes. CK and AK declare that they no competing interests. None of the abovementioned disclosures are related to the present work.