Rheumatoid Arthritis — Cervical Spine¶

Definition¶

Rheumatoid arthritis (RA) affects the cervical spine in approximately 40–80% of patients with established disease. Unlike the seronegative spondyloarthropathies that predominantly affect the sacroiliac joints and lumbar spine, RA has a strong predilection for the upper cervical spine, particularly the atlantoaxial (C1–C2) joint. RA-related cervical spine involvement can cause life-threatening instability and neurological compromise.

Pathophysiology¶

RA causes synovial inflammation (pannus) that erodes bone, cartilage, and ligaments. In the cervical spine, the key targets are the synovial joints — the atlantoaxial articulations, lateral atlanto-occipital joints, and facet joints (C2–C7). Pannus formation around the odontoid process and erosion of the transverse ligament lead to atlantoaxial instability. Progressive facet joint erosion in the subaxial spine causes subluxation, typically in a "staircase" pattern.

Patterns of Cervical Involvement¶

1. Atlantoaxial subluxation — The most common manifestation (see Atlantoaxial Subluxation in RA)
2. Cranial settling (basilar invagination) — Erosion of the lateral masses of C1 allows the odontoid to migrate cranially (see Cranial Settling in RA)
3. Subaxial subluxation — "Staircase" pattern of subluxation at multiple levels from facet joint erosion

Imaging Findings¶

Radiography¶

• Lateral view — Increased anterior atlanto-dental interval (ADI >3 mm in adults), subaxial subluxation
• Flexion-extension views — Dynamic instability at C1–C2 (ADI increases in flexion)

MRI¶

• Pannus — Soft tissue mass around the odontoid, typically low T1, intermediate T2, enhancing. May compress the cord from anterior.
• Cord compression — Evaluate for cord signal change (edema or myelomalacia)
• Erosions — Of the odontoid, lateral masses of C1, and facet joints
• Facet joint synovitis — Enhancement and effusion in the facet joints

CT¶

• Erosions of the odontoid and lateral masses
• Bony detail of atlantoaxial articulation
• Subaxial facet joint erosion and subluxation

Key Points¶

• RA affects the cervical spine in 40–80% of patients, predominantly at C1–C2
• Three patterns: atlantoaxial subluxation, cranial settling, and subaxial subluxation
• Pannus around the odontoid is the characteristic MRI finding
• Pre-operative cervical spine assessment is essential for RA patients undergoing general anesthesia
• MRI evaluates cord compression; CT evaluates bony erosions; flexion-extension radiographs assess dynamic instability

References¶

1. Shlobin NA, Dahdaleh NS. Cervical spine manifestations of rheumatoid arthritis: a review. Neurosurg Rev. 2021;44(4):1957-1965. https://pubmed.ncbi.nlm.nih.gov/33037539/
2. Joaquim AF, Ghizoni E, Tedeschi H, Appenzeller S, Riew KD. Radiological evaluation of cervical spine involvement in rheumatoid arthritis. Neurosurg Focus. 2015;38(4):E4. https://thejns.org/focus/view/journals/neurosurg-focus/38/4/article-pE4.xml
3. Mańczak M, Gasik R. Cervical spine instability in the course of rheumatoid arthritis — imaging methods. Reumatologia. 2017;55(4):201-207. https://pmc.ncbi.nlm.nih.gov/articles/PMC5647537/
4. Lacy J, Bajaj J, Gillis CC. Atlantoaxial Instability. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2023 Jun 12. https://www.ncbi.nlm.nih.gov/books/NBK519563/
5. Expert Panel on Neurological Imaging; Eldaya RW, Parsons MS, Hutchins TA, et al. ACR Appropriateness Criteria® Cervical Pain or Cervical Radiculopathy: 2024 Update. J Am Coll Radiol. 2025;22(5S):S136-S162. https://pubmed.ncbi.nlm.nih.gov/40409873/
6. Atlantoaxial subluxation — rheumatoid arthritis. Radiopaedia.org. https://radiopaedia.org/cases/atlantoaxial-subluxation-rheumatoid-arthritis-1

Related Articles¶

• Atlantoaxial Subluxation in RA
• Cranial Settling in RA
• Atlas and Axis