Cervical spine involvement in longstanding ankylosing spondylitis

Area of Science:

• Rheumatology
• Radiology
• Spinal Imaging

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the axial skeleton.
• Longstanding AS can lead to significant structural changes in the cervical spine, including the atlantoaxial joint.

Purpose of the Study:

• To evaluate the extent of ossification and ankylosis at the atlas and axis in patients with long-standing AS.
• To assess cervical spine radiological involvement and its correlation with disease severity and neurological status.

Main Methods:

• Conventional radiography and multislice CT were used to assess ossification and zygapophyseal (ZA) joint lesions in 61 AS patients (disease duration >7 years).
• Bath Ankylosing Spondylitis Radiology Index (BASRI) was employed for grading radiological changes.
• Neurological examinations and somatosensory evoked potentials (SSEP) were conducted.

Main Results:

• 82% of patients showed cervical spine radiological changes (BASRI score ≥1).
• 60.6% had atlantodental ossification, and over 30% exhibited atlantodental ankylosis.
• Atlantodental ossification and BASRI-cervical spine scores correlated with disease duration; 80.3% had ZA involvement, with 37.7% showing ZA fusion.

Conclusions:

• Cervical spine involvement, including atlantodental ossification or ankylosis, is frequent in long-standing AS.
• The severity of these changes is associated with longer disease duration.
• Despite atlantoaxial subluxation in some cases, significant neurological complications were not observed, potentially due to ankylosis and fusion.