Background: It is accepted among rheumatologists that rheumatoid arthritis (RA) does not involve the FJs of the spine, but the issue is still under debate. Studies that described a prevalence of the facet joints changes in RA patients are scarce, and most of the low methodologic quality.
Aims: To compare the prevalence of FJs changes between patients with RA and ag and sex-matched peers.
Methods: We compared CT scans of 34 patients with RA, who suffered from low back pain, and 70 age and sex-matched controls (people without RA, suffered from low back pain) that were performed in the Department of Radiology, Barzilai Medical Center, Ashqelon, Israel, in 2015-2017.
The osteoarthritic changes in FJs were evaluated (joint space narrowing, marginal osteophytes, articular process hypertrophy, subchondral sclerosis, inter-joint vacuum phenomenon, and subchondral cysts) in addition to the marginal erosions, the most characteristic feature of joint change in RA.
Disease activity characteristics (CRP, ESR, DAS-28, SDAI, and CDAI), duration of RA, age, and gender were taken from patients` clinical charts.
Results: Prevalence of FJs changes in patients with RA and group of age and sex-matched controls were not significantly different at any spinal level or in total L5-S1 score. Marginal erosions, that are a characteristic feature of joint change in RA, were not found in any subject with RA in our sample. In subjects with RA, individuals with affected FJs and without affected FJs have no difference in any disease parameters and markers.
Conclusions: In our sample, we did not find a difference in FJs changes between the subject with RA and control group. The occurrence of FJs changes among subjects with RA had no correlation with disease duration and activity. According to the findings, we may assume, that FJs of the lumbar spine are not involved in the inflammatory process of RA, and their low back pain is not due to inflammation in this region of the spine.
Keywords: rheumatoid arthritis; facet joints; osteoarthritis; lumbar spine; computed tomography
