Noninfective arthritis
Ankylosing spondyloarthritis (AS)

Topic Completed: 1 April 2013

Minor changes: 27 September 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Ankylosing spondyloarthritis [title]

Vijay Shankar, M.D.
Page views in 2019: 1,112
Page views in 2020 to date: 454
Cite this page: Shankar V. Ankylosing spondyloarthritis (AS). website. Accessed May 24th, 2020.
Definition / general
  • Chronic inflammatory disease of axial joints, especially sacroiliac
  • Affects teenage boys, 90% are HLA-B27 positive
  • M:F: 2-3:1
  • Typically involves sacroiliac joints and slowly ascends
  • Chronic synovitis destroys articular cartilage and causes bony ankylosis
  • Inflammation of tendinoligamentous insertion sites cause osteophytes
  • CD3+ T cells and CD68+ macrophages are main inflammatory cells
Clinical features
  • Symptoms: low back pain that gets progressively worse
  • Reactive bone formation may be seen in ring apophysis with erosions of margins
  • Calcification of posterior longitudional ligament is seen
  • In later stages spine appears fused with fixed kyphosis (Bamboo spine)
  • Complications: uveitis, aortitis, amyloidosis
Case reports
Clinical images

Images hosted on other servers:

Anterior flexion

Back to top