Henriksen, M., Christensen, R., Klokker, L., Bartholdy, C., Bandak, E., Ellegaard, K., Boesen, M. P., Riis, R. G., Bartels, E. M., Bliddal, H. Evaluation of the benefit of corticosteroid injection before exercise therapy in patients with osteoarthritis of the knee: a randomized clinical trial. JAMA Internal Medicine 2015; 6: 923-30