Table 2.
Number of r-axSpA patients with progression of facet joint ankylosis over 2-year follow-up
| Reader 1 n (%) | Reader 2 n (%) | |
|---|---|---|
| Whole spine change >0 | 15/50 (30%) | 22/52 (42%) |
| Cervical segment change >0 | 2/44 (4%) | 3/45 (7%) |
| Thoracic segment change >0 | 15/50 (30%) | 17/52 (33%) |
| Lumbar segment change >0 | 3/51 (6%) | 6/52 (12%) |
| Average of 2 readers n (%) | ||
| Whole spine | ||
| Change >0.5 | 24/50 (48%) | |
| Change >SDC (1.98) | 13/50 (26%) | |
| Net progression (>0.5) | 21/50 (42%) | |
| Cervical segment | ||
| Change >0.5 | 1/40 (2.5%) | |
| Change >SDC (0.22) | 3/40 (7.5%) | |
| Net progression | 0/40 (0%) | |
| Thoracic segment | ||
| Change >0.5 | 23/50 (46%) | |
| Change >SDC (2.67) | 7/50 (14%) | |
| Net progression | 21/50 (42%) | |
| Lumbar segment | ||
| Change >0.5 | 5/51 (10%) | |
| Change >SDC (1.14) | 4/51 (8%) | |
| Net progression | 3/51 (6%) | |
Whole spine: n = 50 (r1), n = 52 (r2), n = 50 (average 2 readers).
Cervical segment: n = 44 (r1), n = 45 (r2), n = 40 (average 2 readers).
Thoracic segment: n = 50 (r1), n = 52 (r2), n = 50 (average 2 readers).
Lumbar segment: n = 51 (r1), n = 52 (r2), n = 51 (average 2 readers).
Net progression: number of patients with progression >0.5 – number of patients with progression <−0.5 / total number of patients × 100.
r-axSpA: radiographic axial spondyloarthritis; SDC: smallest detectable change.