PT  - JOURNAL ARTICLE
AU  - Lee, Bong-Woo
AU  - Jung, Joon-Yong
AU  - Kim, Moon-Young
AU  - Hong, Yeon Sik
AU  - Park, Sung-Hwan
AU  - Kang, Kwi Young
TI  - Prevalence and Associated Factors of Facet Joint Ankylosis in Patients With Axial Spondyloarthritis
AID  - 10.3899/jrheum.220749
DP  - 2023 Jun 01
TA  - The Journal of Rheumatology
PG  - 763--768
VI  - 50
IP  - 6
4099  - http://www.jrheum.org/content/50/6/763.short
4100  - http://www.jrheum.org/content/50/6/763.full
SO  - J Rheumatol2023 Jun 01; 50
AB  - Objective To investigate the prevalence of facet joint ankylosis in the whole spine in axial spondyloarthritis (axSpA) using low-dose computed tomography (LDCT), and to identify factors associated with facet joint ankylosis.Methods Whole spine LDCT images from 161 patients with axSpA were examined, and the presence of facet joint ankylosis was assessed (right and left, C2–S1) by 2 readers. Facet joint ankylosis was scored from 0 to 46. Structural damage of vertebral body was assessed using CT Syndesmophyte Score (CTSS). Factors associated with ankylosed facet joint scores for the whole spine were identified using a generalized linear model with a negative binomial distribution.Results Seventy-nine patients (49%) and 70 patients (43%; reader 1 and reader 2, respectively) had ≥ 1 ankylosed facet joint. Facet joint ankylosis was most common in the thoracic spine. The mean score of facet joint ankylosis for the whole spine was 6.6 (SD 11.2) in reader 1 and 4.2 (SD 8.4) in reader 2. Whole spine facet joint ankylosis score positively correlated with Ankylosing Spondylitis Disease Activity Score (ASDAS) and CTSS. In multivariable analysis, the ankylosed facet joint score was associated with ASDAS, sacroiliitis, CTSS, and a history of uveitis in both readers. Uveitis history, ASDAS, and CTSS were associated with whole spine facet joint ankylosis score in subgroup analysis of only radiographic axSpA.Conclusion The prevalence of ankylosed facet joints is high in axSpA, especially in the thoracic segment. The whole spine ankylosed facet joint score is significantly associated with a history of uveitis, ASDAS, sacroiliitis, and syndesmophyte score.