<prompt> Features of Ankylosing spondylitis AS include all of the following EXCEPT:Fibrous ankylosis is pa of pathogenesis of ASBony ankylosis is pa of pathogenesis of ASRoos test is used to test for SacroilitisMarginal syndesmophytes are seen on X-ray  <response>: FEATURES of ankylosing spondilitis- enthesitis and this ultimately leads to joint ankylosis Both bony as well as fibrous ankylosis occurs in AS Marginal syndesmophytes are seen on X-ray Roos test is used for thoracic outlet syndrome. 