Comparison of clinical and demographic findings of patients with total ankylose of the sacroiliac joints and without spine damage in patients diagnosed according to the modified New York criteria

Objective: Bridging syndesmophytes in the spinal column plays a key role in the progression of AS. In this study, we aimed to evaluate patients with ankylosing spondylitis (AS) diagnosed with grade 4 sacroiliitis followed in our rheumatology clinic, without spinal column involvement and with complete spinal ankylosis (bamboo cane vertebra), together with their clinical, demographic and laboratory findings. Materials and Methods: A total of 202 patients with unilateral/bilateral grade 4 sacroiliitis, who were registered in the Dokuz Eylul University Hospital data system, diagnosed with AS according to the modified New York diagnostic criteria, were included in the study. Cervical, dorsal and lumbar radiographs of all patients were evaluated for structural damage, in addition to lateral anterior and anteroposterior aspects, as well as lateral posterior and facet joint involvement. In the study, all radiographs were evaluated twice at separate times. The clinical features of these patient groups, the factors predicting vertebral fusion and the use of anti-TNF were evaluated. Results: It was found that 19 (9.5%) patients had no involvement of the spinal column and 19 (9.5%) had spinal fusion appearance. It was determined that patients with spinal fusion were older (p<0.001) and the frequency of male gender was higher (p=0.042) than patients without any spinal involvement. In the statistical model made to evaluate the factors predicting the development of spinal fusion in patients, only being >45 years old [OR: 10.5, CI: 95%, 2.8-39.2; (p<0.001)] and male gender [OR: 10.5, CI: 95%, 1.14-96.56; (p=0.042)] was found to be effective. TNF usage rates (78.9% vs. 52.6%), TNF switch rates (53.3% vs. 45.5%) and TNF distributions were similar in both groups (p>0.05). Hip involvement characteristics of patients with AS are summarized in . There was no significant difference between the patients with complete spinal fusion and no spinal involvement in terms of right and left hip BASRI scores (p>0.05). Conclusion: In our study, we reached four important clinical results: (1) Spinal fusion was observed in 9.5% of the patients with bilateral Grade 4 sacroiliitis diagnosed with AS, 9.5% had no spinal involvement and 81% had varying degrees of spinal injury. (2) Anti-TNF treatment responses were similar in patients with spinal fusion and no spinal involvement. (3) Except for being >45 years old and having a male gender, no other factor was found to predict the development of spinal fusion. (4) There was no difference in the degree of hip involvement between patients with complete spinal fusion and no spinal involvement. Keywords: Ankylosing spondylitis, bamboo spine, radiographic progression, syndesmophyte, spinal fusion, spondyloarthritis