Table 2 Radiographic outcomes of cervical facet joints and cervical vertebral bodies over time as assessed using individual spinal radiographs
|  | Total spinal radiographs over follow-up (n = 4984) | ||||
|---|---|---|---|---|---|
Baseline (n = 1106) | Y0–Y4 (n = 1235) | Y4–Y8 (n = 1696) | Y8–Y12 (n = 805) | Y12–Y16 (n = 142) | |
Radiographic damage of cervical facet joints | |||||
Cervical facet joint score (0–15), mean ± SD | 1.5 ± 3.9 | 1.8 ± 4.2 | 2.3 ± 4.6 | 3.1 ± 5.2 | 4.1 ± 5.7 |
Median (IQR) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–1.0) | 0.0 (0.0–4.0) | 0.0 (0.0–8.5) |
≥ 1 facet joint ankylosis, n (%) | 130 (11.8%) | 186 (15.1%) | 325 (19.2%) | 199 (24.7%) | 45 (31.7%) |
Ankylosis of all facet joints, n (%) | 44 (4.0%) | 64 (5.2%) | 104 (6.1%) | 60 (7.5%) | 12 (8.5%) |
No. of affected vertebral levels (0–5)a, mean ± SD | 0.4 ± 1.2 | 0.5 ± 1.3 | 0.6 ± 1.4 | 0.8 ± 1.6 | 1.1 ± 1.8 |
Median (IQR) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–2.0) |
Radiographic damage of cervical vertebral bodies | |||||
Cervical mSASSS (0–36), mean ± SD | 8.4 ± 7.8 | 9.3 ± 8.6 | 10.2 ± 9.6 | 11.4 ± 10.6 | 13.7 ± 11.4 |
Median (IQR) | 6.0 (4.0–8.7) | 6.5 (4.4–9.6) | 6.5 (4.4–10.8) | 7.0 (4.4–14.0) | 9.0 (5.3–21.7) |
≥ 1 bridging syndesmophyte, n (%) | 121 (10.9%) | 175 (14.2%) | 306 (18.0%) | 190 (23.6%) | 45 (31.7%) |
Bridges of all vertebral bodies, n (%) | 37 (3.3%) | 48 (3.9%) | 103 (6.1%) | 65 (8.1%) | 16 (11.3%) |
No. of affected vertebral levels (0–5)b, mean ± SD | 0.3 ± 1.0 | 0.4 ± 1.2 | 0.6 ± 1.4 | 0.8 ± 1.6 | 1.1 ± 1.8 |
Median (IQR) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.0 (0.0–1.0) |