AB0156 INCIDENCE OF CERVICAL SPINE INVOLVEMENT IN RHEUMATOID ARTHRITIS, RESULTS FROM A SINGLE CENTRE OBSERVATIONAL STUDY

Background: Rheumatoid arthritis (RA) manifests as a chronic, symmetrical articular disease; any synovial joint may be involved and the cervical spine is another possible affected site [1,2]. Although the cervical spine involvement is a very severe complication of RA, the exact incidence of cervical spine abnormalities in RA is not fully elucidated yet. Objectives: In this work, we aimed at evaluating the incidence of a cervical spine involvement and associated clinical characteristics in patients with RA in a single centre observational study. Methods: In this study, we performed a retrospective analysis of prospectively followed-up patients with RA attending our Rheumatologic Clinic, University of L’Aquila, L’Aquila, Italy, between January 2010 and December 2020. Patients who met the diagnostic criteria of 1987 ACR and/or ACR/EULAR 2010 criteria were assessed. Each patient was investigated for cervical spine involvement occurrence, particularly the atlas-axis cervical involvement. Instrumental imaging evaluation of the cervical spine was performed in all patients with clinical suspicion of involvement, by both MRI and CT examinations. MRI examinations were performed on a 1.5 Tesla scanner, acquiring T1, T2, and STIR sequences on sagittal, coronal and axial planes. CT examinations were performed on a multidetector 320-row CT scanner (Aquilion One,Toshiba) acquired with a thin collimation; soft tissue or bone algorithms were applied for image data reconstruction and analysis. Incident cases of cervical spine involvement were reported as incidence proportion and incidence rate per 1000 person-years at risk. Results: In this evaluation, 347 consecutive patients, (mostly female 87.6%, mean age of 66.1 ± 11.3 years) attending our Rheumatologic Clinic, were studied. The incidence proportion of cervical spine involvement was 2.0% [0.6 – 3.4%], occurring in 7 out of 347 patients, and identified by both MRI and CT scan. Considering over 1623 person-years, an incidence rate of 4.0 × 1000 [3.0 – 5.0] person-years was also estimated. All our patients with cervical spine involvement were characterised by female gender, rheumatoid factor, ACPA, fulfilment of ACR 1987 classificative criteria, and poorly controlled disease activity. Smoking habit and extra-articular manifestations were also frequently reported. Glucocorticoids, methotrexate, and infliximab were mainly administered in these patients. This therapeutic strategy resulted in a complete resolution of the inflammatory synovitis in all but one patient. The latter developed a cervical spinal instability resulting in neurological progression and required a subsequent surgical management. Conclusion: The cervical spine involvement is an uncommon but serious manifestation of RA, since possibly causing severe neurologic damage. A poorly controlled inflammatory process would be an important risk factor for developing a cervical spine involvement in RA, thus, a proper management is required, from an early accurate recognition to a timely therapeutic strategy. MRI could provide a useful clinical tool to early evaluate the cervical spine involvement in RA. Finally, considering the low incidence, further studies are needed to fully estimate the exact incidence of this manifestation, mostly in poorly symptomatic patients. References: [1]Shlobin NA, Dahdaleh NS. Cervical spine manifestations of rheumatoid arthritis: a review. Neurosurg Rev. 2020 Oct 10. Neurosurg Rev. 2020 Oct 10. doi: 10.1007/s10143-020-01412-1. [2]Kothe, R.Rheumatoid instability in the cervical spine: Diagnostic and therapeutic strategies. Orthopade. 2018 Jun;47(6):489-495. Disclosure of Interests: None declared