Text and Data Mining valid from 2020-03-12
Received: 6 January 2020
Accepted: 27 February 2020
First Online: 12 March 2020
Ethics approval and consent to participate
: The study was approved by the ethical committee of the IRCCS Rizzoli Orthopedic Institute (protocol number 11551/CE/US/ml, 5 May 2006).
: Not applicable.
: The authors declare that they have no competing interests.