Better Quantification of Syndesmophyte Growth in Axial Spondyloarthritis

  • Michael M. WardEmail author
  • Sovira Tan
Spondyloarthritis (M Khan, Section Editor)
Part of the following topical collections:
  1. Topical Collection on Spondyloarthritis


Purpose of review

We review new insights to syndesmophyte growth in axial spondyloarthritis revealed by computed tomography (CT).

Recent findings

CT allows full reliable quantitation of syndesmophytes. About 70% of patients had detectable growth in syndesmophyte volume or height in 1 year. Syndesmophyte growth is not uniform, but can be highly heterogeneous even within the same disc space of the same patient. Syndesmophytes are not randomly distributed around the vertebral rim but have preferred locations (posterolateral and anterolateral) which vary along the spine. The frequency of syndesmophyte involvement also varies along the spine. It is highest at the thoracolumbar junction and higher in the thoracic than lumbar spine.


CT syndesmophyte quantitation is a promising tool for studies of medications or biomarkers and their relations with syndesmophyte progression. The localization and growth patterns of syndesmophytes suggest importance for local factors such as mechanical stress.


Axial spondyloarthritis Ankylosing spondylitis Computed tomography Syndesmophytes 



This work was supported by the Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.

Human and Animal Rights and Informed Consent

Written informed consent was obtained for all our studies under IRB-approved protocols.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major Importance

  1. 1.
    Braun J, Baraliakos X, Golder W, Brandt J, Rudwaleit M, Listing J, et al. Magnetic resonance imaging examinations of the spine in patients with ankylosing spondylitis, before and after successful therapy with infliximab: evaluation of a new scoring system. Arthritis Rheum. 2003;48:1126–36.CrossRefPubMedGoogle Scholar
  2. 2.
    Bochkova AG, Levshakova AV, Bunchuk NV, Braun J. Spinal inflammation lesions as detected by magnetic resonance imaging in patients with early ankylosing spondylitis are more often observed in posterior structures of the spine. Rheumatology. 2010;49:749–55.CrossRefPubMedGoogle Scholar
  3. 3.
    Jang JH, Ward MM, Rucker AN, Reveille JD, Davis JC Jr, Weisman MH, et al. Ankylosing spondylitis: patterns of radiographic involvement—a re-examination of accepted principles in a cohort of 769 patients. Radiology. 2011;258:192–8.CrossRefPubMedPubMedCentralGoogle Scholar
  4. 4.
    van der Heijde D, Landewé R, Baraliakos X, Houben H, Tubergen AV, Williamson P, et al. Radiographic findings following two years of infliximab therapy in patients with ankylosing spondylitis. Arthritis Rheum. 2008;58:3063–70.CrossRefPubMedGoogle Scholar
  5. 5.
    van der Heijde D, Landewé R, Einstein S, Ory P, Vosse D, Ni L, et al. Radiographic progression of ankylosing spondylitis after up to two years of treatment with etanercept. Arthritis Rheum. 2008;58:1324–31.CrossRefPubMedGoogle Scholar
  6. 6.
    van der Heijde D, Salonen D, Weissman BN, Landewé R, Maksymowych WP, Kupper H, et al. Assessment of radiographic progression in the spines of patients with ankylosing spondylitis treated with adalimumab for up to 2 years. Arthritis Res Ther. 2009;11:R127.CrossRefPubMedPubMedCentralGoogle Scholar
  7. 7.
    Haroon N, Inman RD, Learch TJ, Weisman MH, Lee M, Rahbar MH, et al. The impact of tumor necrosis factor α inhibitors on radiographic progression in ankylosing spondylitis. Arthritis Rheum. 2013;65:2645–54.PubMedPubMedCentralGoogle Scholar
  8. 8.
    Kim TJ, Shin JH, Kim S, Sung IH, Lee S, Song Y, et al. Radiographic progression in patients with ankylosing spondylitis according to tumor necrosis factor blocker exposure: observation study of Korean Spondyloarthropathy Registry (OSKAR) data. Joint Bone Spine. 2016;83:569–72.CrossRefPubMedGoogle Scholar
  9. 9.
    Ramiro S, van der Heijde D, van Tubergen A, Stolwijk C, Dougados M, van den Bosch F, et al. Higher disease activity leads to more structural damage in the spine in ankylosing spondylitis: 12-year longitudinal data from the OASIS cohort. Ann Rheum Dis. 2014;73:1455–61.CrossRefPubMedGoogle Scholar
  10. 10.
    Wanders A, van der Heijde D, Landewé R, Béhier JM, Calin A, Olivieri I, et al. Nonsteroidal antiinflammatory drugs reduce radiographic progression in patients with ankylosing spondylitis: a randomized clinical trial. Arthritis Rheum. 2005;52:1756–65.CrossRefPubMedGoogle Scholar
  11. 11.
    Sieper J, Listing J, Poddubnyy D, Song IH, Hermann KG, Callhoff J, et al. Effect of continuous versus on-demand treatment of ankylosing spondylitis with diclofenac over 2 years on radiographic progression of the spine: results from a randomised multicentre trial (ENRADAS). Ann Rheum Dis. 2016;75:1438–43.CrossRefPubMedGoogle Scholar
  12. 12.
    Poddubnyy D, Rudwaleit M, Haibel H, Listing J, Märker-Hermann E, Zeidler H, et al. Effect of non-steroidal anti-inflammatory drugs on radiographic spinal progression in patients with axial spondyloarthritis: results from the German Spondyloarthritis Inception Cohort. Ann Rheum Dis. 2012;71:1616–22.CrossRefPubMedGoogle Scholar
  13. 13.
    Baraliakos X, Listing J, Rudwaleit M, Sieper J, Braun J. Development of a radiographic scoring tool for ankylosing spondylitis only based on bone formation: addition of the thoracic spine improves sensitivity to change. Arthritis Care Res. 2009;61:764–71.CrossRefGoogle Scholar
  14. 14.
    Wanders AJ, Landewé R, Spoorenberg A, Dougados M, van der Linden S, Mielants H, et al. What is the most appropriate radiologic scoring method for ankylosing spondylitis? Arthritis Rheum. 2004;50:2622–32.CrossRefPubMedGoogle Scholar
  15. 15.
    Salaffi F, Carotti M, Garofalo G, Giuseppetti GM, Grassi W. Radiological scoring methods for ankylosing spondylitis: a comparison between the Bath Ankylosing Spondylitis Radiology Index and the modified Stoke Ankylosing Spondylitis Spine Score. Clin Exp Rheumatol. 2007;25:67–74.PubMedGoogle Scholar
  16. 16.
    Başkan BM, Sivas F, Inal EE, Duran S, Elverici E, Ozoran K, et al. Comparison of the Bath Ankylosing Spondylitis Radiology Index and the modified Stoke Ankylosing Spondylitis Spine Score in Turkish patients with ankylosing spondylitis. Clin Rheumatol. 2010;29:65–70.CrossRefPubMedGoogle Scholar
  17. 17.
    Ulusoy H, Kaya A, Kamanli A, Akgol G, Ozgocmen S. Radiological scoring methods in ankylosing spondylitis: a comparison of the reliability of available methods. Acta Reumatol Port. 2010;35:170–5.PubMedGoogle Scholar
  18. 18.
    Claudepierre P, de Hooge MS, Feydy A, Reijnierse M, Saraux A, Dougados M, et al. Reliability of mSASSS scoring in everyday practice in DESIR-cohort study centres: cross-sectional study of agreement with trained readers. Ann Rheum Dis. 2016;75:2213–4.CrossRefPubMedGoogle Scholar
  19. 19.
    Ward MM, Hendrey MR, Malley JD, Learch TJ, Davis JC, Reveille JD, et al. Clinical and immunogenetic prognostic factors for radiographic severity in ankylosing spondylitis. Arthritis Care Res. 2009;61:859–66.CrossRefGoogle Scholar
  20. 20.
    Poddubnyy D, Haibel H, Listing J, Märker-Hermann E, Zeidler H, Braun J, et al. Baseline radiographic damage, elevated acute-phase reactant levels, and cigarette smoking status predict spinal radiographic progression in early axial spondylarthritis. Arthritis Rheum. 2012;64:1388–98.CrossRefPubMedGoogle Scholar
  21. 21.
    Tan S, Yao J, Ward MM, Yao L, Summers RM. Computer aided evaluation of ankylosing spondylitis using high-resolution CT. IEEE Trans Med Imaging. 2008;27:1252–67.CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Tan S, Yao J, Yao L, Ward MM. Improved precision of syndesmophyte measurement for the evaluation of ankylosing spondylitis using CT: a phantom and patient study. Phys Med Biol. 2012;57:4683–704.CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Tan S, Yao J, Flynn JA, Yao L, Ward MM. Quantitation of circumferential syndesmophyte height along the vertebral rim in ankylosing spondylitis using computed tomography. J Rheumatol. 2015;42:472–8.CrossRefPubMedGoogle Scholar
  24. 24.
    Tan S, Yao J, Flynn JA, Yao L, Ward MM. Quantitative measurement of syndesmophyte volume and height in ankylosing spondylitis using CT. Ann Rheum Dis. 2014;73:544–50.CrossRefPubMedGoogle Scholar
  25. 25.
    •• Tan S, Yao J, Flynn JA, Yao L, Ward MM. Quantitative syndesmophyte measurement in ankylosing spondylitis using CT: longitudinal validity and sensitivity to change over 2 years. Ann Rheum Dis. 2015;74:437–43. This study shows the high sensitivity to change of quantitative syndesmophyte measures using CT. CrossRefPubMedGoogle Scholar
  26. 26.
    Liang MH, Fossel AH, Larson MG. Comparisons of five health status instruments for orthopedic evaluation. Med Care. 1990;28:632–42.CrossRefPubMedGoogle Scholar
  27. 27.
    • Tan S, Yao J, Flynn JA, Yao L, Ward MM. Dynamics of syndesmophyte growth in AS as measured by quantitative CT: heterogeneity within and among vertebral disc spaces. Rheumatology. 2015;54:972–80. This study shows high heterogeneity in syndesmophyte growth rates even within the same disc space of the same patient. CrossRefPubMedGoogle Scholar
  28. 28.
    Baraliakos X, Listing J, Rudwaleit M, Haibel H, Brandt J, Sieper J, et al. Progression of radiographic damage in patients with ankylosing spondylitis: defining the central role of syndesmophytes. Ann Rheum Dis. 2007;66:910–5.CrossRefPubMedPubMedCentralGoogle Scholar
  29. 29.
    van Tubergen A, Ramiro S, van der Heijde D, Dougados M, Mielants H, Landewé R. Development of new syndesmophytes and bridges in ankylosing spondylitis and their predictors: a longitudinal study. Ann Rheum Dis. 2012;71:518–23.CrossRefPubMedGoogle Scholar
  30. 30.
    •• Tan S, Dasgupta A, Yao J, Flynn JA, Yao L, Ward MM. Spatial distribution of syndesmophytes along the vertebral rim in ankylosing spondylitis: preferential involvement of the posterolateral rim. Ann Rheum Dis. 2016;75:1951–7. This study shows the spatial distribution of syndesmophytes along the vertebral rim is not random but has preferred locations. CrossRefPubMedPubMedCentralGoogle Scholar
  31. 31.
    •• Tan S, Yao L, Ward MM. Thoracic syndesmophytes commonly occur in the absence of lumbar syndesmophytes in ankylosing spondylitis: a computed tomography study. J Rheumatol. 2017;44:1828–32. The first CT study of thoracic syndesmophytes. CrossRefPubMedGoogle Scholar
  32. 32.
    Braun J, Baraliakos X, Golder W, Hermann KG, Listing J, Brandt J, et al. Analysing chronic spinal changes in ankylosing spondylitis: a systematic comparison of conventional x-rays with magnetic resonance imaging using established and new scoring systems. Ann Rheum Dis. 2004;63:1046–55.CrossRefPubMedPubMedCentralGoogle Scholar
  33. 33.
    • de Bruin F, de Koning A, van der Berg R, Baraliakos X, Braun J, Ramiro S, et al. Development of the CT syndesmophyte score (CTSS) in patients with ankylosing spondylitis: data from the SIAS cohort. Ann Rheum Dis. 2018;77:371–7. The first study of syndesmophytes using low-dose CT. CrossRefPubMedGoogle Scholar

Copyright information

© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2018

Authors and Affiliations

  1. 1.Intramural Research ProgramNational Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of HealthBethesdaUSA

Personalised recommendations