Received: 25 October 2019
Accepted: 11 February 2020
First Online: 17 February 2020
Ethics approval and consent to participate
: The study protocol of this study was approved by the institutional ethics committee (Ethik-Kommission der Medizinischen Fakultät der Universität Leipzig, reference: 169/18-ek). As approved by the ethics committee, consent was given verbally by those patients contacted by phone, and no consent was required for chart review of patients who had deceased or could not be contacted by phone.
: GO and AH are Associated Editors of BMC Musculoskeletal Disorders. The other authors declare that they have no conflicts of interest.