Lumbar spine involvement
| Ankylosing spondylitis | Enteropathic spondylitis | Psoriatic spondylitis | Reactive arthritis | |
|---|---|---|---|---|
| Number of films available (no of cases) | 78/91 | 25/31 | 28/34 | 5/7 |
| Worst grade (number (%)) grades 3–4 | 43 (55) | 10 (40) | 7 (25) | 1 (20) |
| Number (%) symmetry4-150 | 38/52 (73) | 8/16 (50) | 4/14 (29) | 2/3 (67) |
| Paravertebral ossification (number (%)) | 1 (1) | 1 (4) | 1 (4) | 0 |
| Chunky syndesmophytes (number (%))4-150 | 12/52 (23) | 3/16 (19) | 5/14 (36) | 1/3 (33) |
| Ligamentous calcification (number (%)) | 11 (14) | 1 (4) | 1 (4) | 0 |
| Squaring (number (%)) | 15 (19) | 1 (4) | 1 (4) | 0 |
| Romanus lesion (number (%)) | 17 (22) | 0 | 4 (14) | 3 (60) |
| Spinal pseudarthrosis (number (%)) | 2 (3) | 0 | 1 (4) | 0 |
| Zygoapophyseal ankylosis (number (%)) | 16 (21) | 4 (16) | 0 | 0 |
| Discitis (number (%)) | 5 (6) | 2 (8) | 1 (4) | 0 |
| Bamboo spine (number (%)) | 9 (12) | 3 (12) | 0 | 0 |
↵4-150 Note data on symmetry and syndesmophyte morphology only apply to severity grades 2–4: the number of available films is given by the denominator.