Radiologic changes of cervical spine in ankylosing spondylitis

Ankylosing spondylitis (AS) is characterised by its effects on the axial skeleton. The cervical spine is also vulnerable to the disease process. Our aim was to determine the frequency of radiologic changes to the cervical spine and their correlation with clinical variables. We also used the Bath Ankylosing Spondylitis Radiology Index (BASRI) system, which is one of the reliable scoring systems of radiography, to score the global radiologic changes to the cervical and lumbar spine and the hip joints in our AS cohort. There were 181 patients with anteroposterior and lateral full-flexion views on radiography of the cervical spine here included in the study. A radiologist examined the radiologic changes to all anatomical compartments of the cervical spine in detail and graded them according to the BASRI system. We used the clinical and demographic data of our AS cohort to determine their relation to the radiographic changes. Eighty-eight patients (48.6%) showed radiological changes to the cervical spine; to the discovertebral joint 35.9%; the apophyseal joint 26.0%; atlantoaxial articulation 22.1% (atlantoaxial subluxation 13.8%); the costovertebral joint 18.2%; and to the posterior ligamentous attachment 11.6%. Using the BASRI system, 73 patients (40.3%) showed radiologic changes to the cervical spine and were graded as score 1 (1.7%), 2 (22.7%), 3 (6.6%) or 4 (9.4%). Among those graded as normal by the BASRI system, 17 showed some changes the cervical spine, such as atlantoaxial joint subluxation or narrowing, and severe osteoporosis with no other radiographic changes. Current age, disease duration, inflammatory back pain and cervical symptoms were associated with the radiographic changes to the cervical spine. The BASRI-cervical spine score correlated with the BASRI-lumbar spine and hip joint score, sacroiliitis, disease duration, and duration of inflammatory back pain and cervical symptoms. Our data suggest that radiographic changes to the cervical spine are frequent in AS, and can be predicted in the patients with old age, long duration of disease and inflammatory back pain, and cervical symptoms. Also, the BASRI scoring system showed similar results as a detailed assessment of the cervical spine in our study.