# Prevalence and location of inflammatory and structural lesions in patients with rheumatoid arthritis and radiographic axial spondyloarthritis with chronic neck pain evaluated by magnetic resonance imaging

## TL;DR

This study uses MRI to compare inflammatory and structural lesions in the cervical spine of patients with rheumatoid arthritis and radiographic axial spondyloarthritis who suffer from chronic neck pain.

## Contribution

The study identifies distinct patterns of MRI lesions in RA and r-axSpA patients with chronic neck pain, highlighting differences in lesion locations and prevalence.

## Key findings

- RA patients showed more synovitis and erosive osteochondrosis, while r-axSpA patients had more bone marrow edema in lower cervical segments.
- Neck pain severity differed between RA and r-axSpA patients, with RA reporting higher pain levels.
- Inflammatory lesions were predominantly in the craniocervical area for RA and lower cervical segments for r-axSpA.

## Abstract

Define the prevalence and location of inflammatory and structural lesions on magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) and radiographic axial spondyloarthritis (r-axSpA) with neck pain as leading clinical symptom.

Patients with diagnosis of RA and r-axSpA were consecutively included if they had chronic (> 3 months) neck pain. Clinical assessment, neck pain questionnaires and MRIs of the cervical spine (CS) were performed.

107 patients (59 RA and 48 r-axSpA) were included. While there was no difference in the Northwick-Park-Neck-Pain-questionnaire, patients with RA reported higher neck pain compared to r-axSpA on a numeric rating scale (5.0 ± 3.6 vs. 3.0 ± 3.1; p = 0.003). Inflammatory lesions occurred predominantly in the craniocervical area in RA and in the lower CS segments in r-axSpA. Bone marrow edema (BME) was more frequent in axSpA (BME-score axSpA/RA: 0.35vs0.17; p < 0.001) while synovitis was visible in both but was more prevalent in RA (synovitis-score axSpA/RA: 0.02vs0.1; p < 0.001). BME was found in 8 (13.6%) vertebral corner vs. 9 (18.8%), in 2 (3.4%) facet joints vs. 7 (14.6%) and in 1 (1.7%) spinous processes vs. 9 (18.8%) in patients with RA/r-axSpA. In contrast, more patients with RA (30.5% vs6.3%) showed erosive osteochondrosis with endplate BME (p = 0.002).

While involvement of upper cervical inflammation was typically present in RA, r-axSpA patients showed more BME in lower CS segments, vertebral corners, facet joints and spinous processes. Neck pain is linked to upper and lower inflammatory and structural lesions of the CS in both diseases.