Factors Associated with Complete Spinal Fusion in Patients with Ankylosing Spondylitis

Yasmin Maldonado¹, Michael Weisman ², Lianne Gensler ³, Michael Ward ⁴, Matthew Brown ⁵, MinJae Lee ⁶, Mark Hwang ⁶, Mariko Ishimori ⁷, Amirali Tahanan ⁶, Tom Learch ⁷, Mohammad Rahbar ⁶ and John Reveille ⁸, ¹The University of Texas-McGovern Medical School, Houston, TX, ²David Geffen School of Medicine at UCLA, Los Angeles, CA, ³University San Francisco California, San Francisco, CA, ⁴NIAMS, Bethesda, MD, ⁵Queensland University of Technology, Queensland, Australia, ⁶University of Texas-McGovern Medical School, Houston, TX, ⁷Cedars-Sinai Medical Center, Los Angeles, CA, ⁸University of Texas McGovern Medical School, Houston

Meeting: 2019 ACR/ARP Annual Meeting

Keywords: Ankylosing spondylitis (AS), race/ethnicity and severity, radiography

Session Information

Date: Sunday, November 10, 2019

Title: Spondyloarthritis Including Psoriatic Arthritis – Clinical Poster I: Axial Spondyloarthritis, Clinical Features

Session Type: Poster Session (Sunday)

Session Time: 9:00AM-11:00AM

Background/Purpose: Most patients with ankylosing spondylitis (AS) do not develop complete spinal fusion. The purpose of this study was to compare patients with complete spinal fusion defined here as having a Modified Stoke Ankylosing Spondylitis Scoring System (mSASSS) of score of 72 (indicating complete fusion of the cervical and lumbar spine) versus those with no syndesmophyte formation (mSASSS=0) adjusted for disease duration.

Methods: Patient meeting modified New York Criteria for AS enrolled in a longitudinal study of outcome were included in this study. All films were scored for the modified Stoke Ankylosing Spondylitis Scoring System by the same musculoskeletal radiologist (TJL). Sociodemographic features, medication utilization, comorbidities, disease activity (BASDAI, ASDAS), functional impairment (BASFI), joint counts, metrology and enthesitis assessment was recorded, and HLA-B typing at baseline and C-reactive protein, and ESR obtained at each study visit. Pelvic, lumbar and cervical spine radiographs were obtained at baseline visit as well as every two years thereafter. Univariable logistic regression models were conducted to evaluate the factors that were associated with complete spinal fusion (mSASSS=72) compared with those with no radiographic stigmata of AS in the lumbar and cervical spine (mSASSS=0) after adjusting for study site and disease duration.

Results: Of 1253 AS patients meeting modified New York criteria enrolled in a longitudinal study of outcome, 371 had either complete spinal fusion at most recent radiographic assessment(i.e., mSASSS of 72, n=63, of whom only four were women); or no spinal fusion (i.e., mSASSS of 0, n=308). These were included in this statistical analysis. Median Follow-up was 1.92 years (IQR 0,4) (maximum=13 years). Median number of mSASSS sets was 2 (IQR= [1,3]) and mean disease of duration was 17.46 years (SD=12.9). Univariable analysis after adjusting for disease duration (Table 1) showed associations of complete spinal fusion with male gender, nonwhite ethnicity, older age at assessment and at disease onset, a history of smoking, greater functional impairment,not being employed, a negative family history of AS and elevated baseline C-reactive protein.

Conclusion: These data suggest that complete spinal fusion in patients with AS is most highly associated with greater age at disease onset, non-white ethnicity, male gender, as well as with objective (but not subjective) markers of disease activity.

†: disease duration was adjusted; * data at the same visit when the last available radiograph data were collected

Disclosure: Y. Maldonado, None; M. Weisman, AbbVie, 9, Boehringer Ingelheim, 9, Eli Lilly, 5, Lilly, 5, 9, Novartis, 5, Paul Hastings, 9, SetPoint Medical, 9, Takeda, 9, Tharpe & Howell LLP, 9, UCB, 5; L. Gensler, AbbVie, 2, 5, Abbvie, 2, 9, Amgen, 2, Amgen, AbbVie and Novartis, 2, Center for Disease Control, 8, Division of Vaccine Injury Compensation, 8, Eli Lilly, 5, 9, Eli Lilly and Company, 9, Galapagos, 5, 9, Galapagos, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, 5, Janssen, 5, 9, Novartis, 2, 5, 9, Pfizer, 2, 9, Spondylitis Association of America, 6, Spondyloarthritis Research and Treatment Network (SPARTAN), 6, UCB, 2, 5, 9, UCB Pharma, 2, 9; M. Ward, None; M. Brown, None; M. Lee, None; M. Hwang, Eli Lilly, 2; M. Ishimori, None; A. Tahanan, None; T. Learch, None; M. Rahbar, None; J. Reveille, Abbvie, 2, CB, 5, Eli Lilly, 2, 5, 8, Janssen, 2, Janssen Research & Development, LLC, 2, Novartis, 5, Pfizer, 2, 5, UCB, 5.

To cite this abstract in AMA style:

Maldonado Y, Weisman M, Gensler L, Ward M, Brown M, Lee M, Hwang M, Ishimori M, Tahanan A, Learch T, Rahbar M, Reveille J. Factors Associated with Complete Spinal Fusion in Patients with Ankylosing Spondylitis [abstract]. Arthritis Rheumatol. 2019; 71 (suppl 10). https://acrabstracts.org/abstract/factors-associated-with-complete-spinal-fusion-in-patients-with-ankylosing-spondylitis/. Accessed .

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