The aim of this study was to compare the prevalence of lumbar spondylolisthesis (SPL) in patients suffering from low back pain (LBP) with or without rheumatoid arthritis (RA) and to identify potential factors associated with SPL in patients with RA.
We performed a case-control study. Cases and control patients had chronic LBP (more than 4 weeks). Patient with RA fulfilled the 2010 ACR/EULAR criteria. The main outcome was the presence of lumbar SPL on lumbar X-ray. The prevalence of SPL between RA and control patients was compared using chi-squared test. Potential factors associated with SPL in patients with RA were investigated by univariate and multivariate analysis, estimating odds ratios (ORs) and 95% confidence intervals (95% CIs).
A total of 67 cases and 83 controls were included. Median [interquartile range] age of patients with RA was 60.0 years [51.0-72.0]; 80.6% were females; and 92.5% and 83.6% were positive for anti-citrullinated protein antibodies (ACPAs) or rheumatoid factor, respectively. Mean RA disease duration was 11.2 ± 8.7 years. SPL was more frequent in patients with RA than controls (41.8% versus 18.1%, P = 0.001). Adjusted to gender, RA was associated with increased prevalence of SPL (OR 3.15 [95% CI 1.48-6.70], P = 0.003). Among patients with RA, SPL was mainly Grade 1 (85.7%). Multivariate analysis revealed SPL is associated with increased age in patients with RA (OR 1.06 [1.02-1.11], P = 0.004).
In a population of patients with chronic LBP, the prevalence of lumbar SPL was higher with than without RA. SPL might be explained by synovitis of lumbar facet joints.