Erratum to: Mod Rheumatol (2010) 20:325–330 DOI 10.1007/s10165-010-0277-7

Two affiliations of Prof. Paul Emery were not included. The additional affiliations are as shown below.

Section of Musculoskeletal Disease, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK

NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds Teaching Hospitals Trust, Leeds, UK