Scores for facet joint ankylosis at each level. Missing data were due to difficulties interpreting the radiographs (n = 73).
| Facet Level | No Ankylosis | Ankylosis | Missing Data |
|---|---|---|---|
| C2–C3 | 53 | 16 | 4 |
| C3–C4 | 54 | 14 | 5 |
| C4–C5 | 58 | 10 | 5 |
| C5–C6 | 57 | 11 | 5 |
| T12–L1 | 52 | 5 | 16 |
| L1–L2 | 52 | 6 | 15 |
| L2–L3 | 53 | 6 | 14 |
| L3–L4 | 52 | 8 | 13 |
| L4–L5 | 52 | 8 | 13 |
| L5–S1 | 47 | 6 | 20 |