Received: 17 December 2020
Accepted: 31 January 2021
First Online: 16 February 2021
Change Date: 12 April 2021
Change Type: Correction
Change Details: A Correction to this paper has been published:
Change Details: https://doi.org/10.1186/s12891-021-04219-3
Ethics approval and consent to participate
: The study was approved by the Kuopio university hospital ethics committee on October 28, 1986 and was performed in accordance with the ethical standards set by the Declaration of Helsinki. All participants gave their informed consent to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.