The extension of the ankylosing spondylitis "dagger sign" into the sacrum.
Olivieri
I
I
Ciancio
G
G
Scarano
E
E
Padula
A
A
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