Cervical spine involvement
| Ankylosing spondylitis | Enteropathi c spondylitis | Psoriatic spondylitis | Reactive arthritis | |
|---|---|---|---|---|
| Number of films available (no of cases) | 58/91 | 11/31 | 19/34 | 5/7 |
| Worst grade (number (%)) grades 3–4 | 29 (50) | 5 (45) | 9 (47) | 0 |
| Number (%) symmetry6-150 † | 19/19 (100) | 2/4 (50) | 7/7 (100) | 0 |
| Paravertebral ossification (number (%)) | 1 (2) | 0 | 2 (11) | 0 |
| Chunky syndesmophytes (number (%))6-150 | 3/34 (9) | 1/6 (17) | 5/12 (42) | 1/1 (100) |
| Ligamentous calcification (number (%)) | 1 (2) | 2 (18) | 0 | 0 |
| Squaring (number (%)) | 3 (5) | 0 | 0 | 0 |
| Romanus lesions (number (%)) | 1 (2) | 0 | 0 | 0 |
| Spinal pseudarthrosis (number (%)) | 1 (2) | 1 (9) | 0 | 0 |
| Zygoapophyseal ankylosis (number (%)) | 10 (17) | 0 | 2 (11) | 0 |
| Discitis (number (%)) | 0 | 1 (9) | 0 | 0 |
| Bamboo spine (number (%)) | 5 (9) | 0 | 1 (5) | 0 |
↵6-150 Note data on symmetry and syndesmophyte morphology only apply to severity grades 2–4: the number of available films is given by the denominator. †It was not possible to evaluate cervical symmetry in 23 cases because syndesmophytes were only seen on lateral radiographs.