Cai G, Cicuttini F, Aitken D, et al. - This study was undertaken to assess the value of radiographic- and MRI-defined tibiofemoral osteoarthritis (ROA and MRI-OA, respectively) and in combination for predicting tibial cartilage loss, knee pain and disability and total knee replacement (TKR) in a population-based cohort. Researchers conducted a radiograph and 1.5T MRI of the right knee. They characterized ROA and MRI-OA at baseline according to the Osteoarthritis Research Society International atlas and a published Delphi exercise, respectively. They assessed tibial cartilage volume over 2.6 and 10.7 years. They further analyzed knee pain and disability at baseline, 2.6, 5.1 and 10.7 years. Right-sided TKRs were tested over 13.5 years. A total of 574 participants were included in the study(mean 62 years, 49% female). For predicting structural or symptomatic OA progression , the Delphi definition of MRI-OA is not superior to ROA but, combining MRI-OA and ROA has much stronger predictive validity.