Dammerer, D. ., Liebensteiner, M. ., Kujala, U. ., Emmanuel, K. ., Kopf, S. ., Dirisamer, F. ., & Giesinger, J. . (2018). Validation of the German version of the Kujala score in patients with patellofemoral instability: a prospective multi-centre study. Archives of Orthopaedic and Trauma Surgery. https://doi.org/10.1007/s00402-018-2881-5 (Original work published 2018)