Received: 10 January 2019
Accepted: 23 August 2019
First Online: 3 September 2019
Ethics approval and consent to participate
: The trials were approved by all applicable regulatory and ethical bodies before initiation. All participating subjects provided written consent to participate in the trial before any trial procedure was performed.
: Not applicable.
: ARB, IB, ACBJ, CC, BJR, JRA and MAK are full-time employees in Nordic Bioscience, a company engaged in biomarker research and development of treatments for osteoarthritis. The ELISA assays for uCTX-I, uCTX-II and N-MID osteocalcin were developed by Nordic Bioscience but were acquired by Immunodiagnostic Systems UK as Urine Beta Crosslaps®, Urine Cartilaps® and N-MID® Osteocalcin respectively in 2007. ARB, ACBJ, CC, BJR, JRA and MK are shareholders of Nordic Bioscience. BJR and CC are major shareholders and board members of Nordic Bioscience.