The approach consortium: a 2-year, European, cohort study to describe, validate, and predict phenotypes of knee osteoarthritis by use of clinical, imaging, and biochemical markers. (April 2018) - van Helvoort, E.M.; van Spil, W.E.; Marijnissen, A.C.; Welsing, P.M.; Bay-Jensen, A.C.; Hussaarts, L.; Ladel, C.; Lalande, A.; Larkin, J.; Levesque, M.C.; Loughlin, J.; Mobasheri, A.; et al.