Validation of a new topographic classification of bone marrow lesions in the knee: the six-letter system. - Compagnoni, Riccardo; Lesman, Jędrzej; Ferrua, Paolo; Menon, Alessandra; Minoli, Carlo; Gallazzi, Mauro; Domżalski, Marcin; Randelli, Pietro (Knee Surgery, Sports Traumatology, Arthroscopy, 2021)