Number, sex, tonsillar location, and Cobb angles of patients analyzed
| No. | Females | Mean Age (yr) | Age Range (yr) | Minimum Tonsillar Herniation (mm) | Mean and Range of Cobb Angles | |
|---|---|---|---|---|---|---|
| Chiari | 2 | 1 | 9 | 3–14 | 25 | 18° (16°–19°) |
| Chiari plus syrinx | 20 | 11 | 9 | 12–19 | 8 | 34° (15°–87°) |
| Syrinx only | 8 | 3 | 10 | 1–17 | N/A | 20° (15°–40°) |
| No Chiari or syrinx | 24 | 19 | 11 | 1–18 | N/A | 35° (15°–82°) |
Note:—N/A indicates not applicable.