TY - JOUR
T1 - Spatial distribution of syndesmophytes along the vertebral rim in ankylosing spondylitis
T2 - Preferential involvement of the posterolateral rim
AU - Tan, Sovira
AU - Dasgupta, Abhijit
AU - Yao, Jianhua
AU - Flynn, John A.
AU - Yao, Lawrence
AU - Ward, Michael M.
N1 - Publisher Copyright:
© 2016 Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-And-licensing/.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Objective Syndesmophytes in ankylosing spondylitis (AS) can occur anywhere along the vertebral rim, but little is known about how and where they develop, and particularly if they first form in certain locations along the rim. This information might provide clues to their aetiology. We examined the spatial distribution of syndesmophytes in the thoracolumbar spine in patients with AS using CT. Methods We performed lumbar spine CT scans in 50 patients and used a validated computer algorithm to measure syndesmophyte heights in six intervertebral disc spaces. We measured heights every five radial degrees around the rim of each superior and inferior vertebral endplate. Results Syndesmophytes were observed in 208 of 296 intervertebral disc spaces. Both ascending and descending syndesmophytes were non-randomly distributed along the vertebral rim (p<0.0001 for deviation from uniform distribution). Syndesmophytes occurred most often at the posterolateral vertebral rim, and least commonly at the posterior rim and anterior rim. In disc spaces with only small isolated syndesmophytes, these were also most likely to occur at the posterolateral rim. Syndesmophyte distribution varied with the vertebral level. Localisation at the posterolateral rim was most pronounced at T10-T11, T12-T12 and T12-L1, while L2-L3 and L3-L4 exhibited little localisation. Conclusions Syndesmophytes are not randomly distributed around the vertebral rim, as might be expected if they develop solely in response to inflammation. Rather, they preferentially occur, and likely develop first, at the posterolateral rim. Studying factors that can lead to this pattern may help elucidate how syndesmophytes develop.
AB - Objective Syndesmophytes in ankylosing spondylitis (AS) can occur anywhere along the vertebral rim, but little is known about how and where they develop, and particularly if they first form in certain locations along the rim. This information might provide clues to their aetiology. We examined the spatial distribution of syndesmophytes in the thoracolumbar spine in patients with AS using CT. Methods We performed lumbar spine CT scans in 50 patients and used a validated computer algorithm to measure syndesmophyte heights in six intervertebral disc spaces. We measured heights every five radial degrees around the rim of each superior and inferior vertebral endplate. Results Syndesmophytes were observed in 208 of 296 intervertebral disc spaces. Both ascending and descending syndesmophytes were non-randomly distributed along the vertebral rim (p<0.0001 for deviation from uniform distribution). Syndesmophytes occurred most often at the posterolateral vertebral rim, and least commonly at the posterior rim and anterior rim. In disc spaces with only small isolated syndesmophytes, these were also most likely to occur at the posterolateral rim. Syndesmophyte distribution varied with the vertebral level. Localisation at the posterolateral rim was most pronounced at T10-T11, T12-T12 and T12-L1, while L2-L3 and L3-L4 exhibited little localisation. Conclusions Syndesmophytes are not randomly distributed around the vertebral rim, as might be expected if they develop solely in response to inflammation. Rather, they preferentially occur, and likely develop first, at the posterolateral rim. Studying factors that can lead to this pattern may help elucidate how syndesmophytes develop.
KW - Ankylosing Spondylitis
KW - Outcomes research
KW - Spondyloarthritis
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U2 - 10.1136/annrheumdis-2015-208802
DO - 10.1136/annrheumdis-2015-208802
M3 - Article
C2 - 26797721
AN - SCOPUS:84956614624
SN - 0003-4967
VL - 75
SP - 1951
EP - 1957
JO - Annals of the rheumatic diseases
JF - Annals of the rheumatic diseases
IS - 11
ER -