title: The extension of the ankylosing spondylitis "dagger sign" into the sacrum.
authors: I
authors: I
authors: Olivieri
authors: G
authors: G
authors: Ciancio
authors: E
authors: E
authors: Scarano
authors: A
authors: A
authors: Padula
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D009999:Ossification, Heterotopic / Q000209:etiology; D011859:Radiography; D012447:Sacrum / Q000000981:diagnostic imaging*; D013167:Spondylitis, Ankylosing / Q000000981:diagnostic imaging* / Q000503:physiopathology