Rheumatoid Arthritis and Cervical Spine Involvement
Rheumatoid arthritis does significantly increase the risk of cervical spine pathology, but this manifests primarily as inflammatory atlantoaxial instability, cranial settling, and subaxial subluxation—not typical degenerative facet arthropathy or spondylosis seen in the general population. The cervical spine involvement in RA represents a distinct inflammatory process rather than simple degenerative disease 1, 2.
Key Distinctions in Cervical Pathology
The cervical spine manifestations in RA are fundamentally different from degenerative cervical spondylosis:
RA causes inflammatory destruction of the atlantoaxial joint (C1-C2), ligamentous laxity from chronic synovitis, and bony erosions—not the typical facet joint osteoarthritis seen in aging 2, 3.
Anterior atlantoaxial subluxation (AAS) is the most common deformity in RA, occurring in 9-88% of patients, resulting from inflammatory destruction of the transverse and alar ligaments 1, 4.
Subaxial cervical involvement occurs in 85% of symptomatic RA patients, but comparative analysis reveals significant differences from degenerative spondylosis: RA patients show subchondral bone inflammation, ligamentous inflammatory changes, and secondary vertebral instability or ankylosis—not simple disc degeneration 5.
Clinical Timeline and Risk Factors
Cervical spine involvement typically occurs after 10 years of RA disease duration, though onset can range from 3 months to 45 years after peripheral synovitis in patients with seropositive erosive disease 1.
Early cervical involvement is rare but possible, with documented cases of cervical myelopathy from C1-C2 rheumatoid pannus occurring before or concurrent with peripheral synovitis 1.
The pathophysiology involves chronic synovitis leading to bony erosion and ligamentous laxity, resulting in instability and subluxation rather than degenerative facet hypertrophy 2.
Comparison with Degenerative Spondylosis
When RA patients develop subaxial stenosis, it represents a hybrid process:
Both inflammatory and mechanical-degenerative changes contribute to subaxial stenosis in RA patients 5.
Discopathy and end-plate osteophytosis occur in both RA and spondylosis, but in RA these coincide with acute inflammatory changes in subchondral bone and ligaments, plus secondary destruction (vertebral instability) or repair (vertebral ankyloses) 5.
Despite the frequency of subaxial stenosis in RA (85%), it is not usually related to myelopathy symptoms, even with MRI evidence of cord compression—a key difference from degenerative spondylosis where stenosis more reliably predicts neurological dysfunction 5.
Clinical Implications for Management
Optimal disease activity control is the primary strategy to prevent cervical spine involvement:
Disease-modifying antirheumatic drugs (DMARDs) have reduced the incidence of cervical spine manifestations in RA, as early pharmacotherapy may slow progression of rheumatoid cervical disease 2, 3.
Serial neurological examinations are the best noninvasive diagnostic tool, as clinical findings can be confounded by multifocal joint involvement 2.
Lateral flexion-extension radiographs should be obtained periodically and used to "clear" the cervical spine before elective surgery requiring general anesthesia 2.
Critical Pitfalls to Avoid
Do not assume cervical symptoms in RA patients represent typical degenerative disease:
Symptoms of cervical pain and myelopathy should prompt thorough neurological examination with imaging, as inflammatory instability requires different management than degenerative spondylosis 1.
MRI has higher sensitivity for detecting bone erosions compared to conventional radiography and identifies earlier signs of RA involvement 1.
Operative intervention before advanced myelopathy results in improved outcomes, making early recognition critical 2.
The posterior atlantodens interval less than 14 mm correlates with neurologic deficit, representing a key measurement distinct from degenerative spondylosis assessment 4.