Table 3.
Craniomorphometric and Volumetric Evaluation of Subjects With Basilar Invagination
| Variable | FD/MAS + craniofacial FD | FD/MAS | No FD/MAS | |
|---|---|---|---|---|
| Basilar invagination (n = 12) |
No basilar invagination (n = 146) |
No craniofacial FD (n = 13) |
Controls (n = 10) |
|
| Clivus length (mm) | 43.3 (31.3–54.3) | 44.5 (32.6–60.8) | 45.3 (39.1–49.3) | 45.3 (39–50.4) |
| Foramen magnum length (mm) | 29.9 (23.0–34.4)a,b,c | 34.1 (20.3–41.5) | 35.8 (33.3–38.7) | 36.0(31.5–40.5) |
| Supraocciput length (mm) | 43.4 (36.3–53.9) | 40.6 (30.6–58.8) | 40.9 (34.0–45.4) | 39.9 (33.7–45.5) |
| Boogaard angle (degrees) | 139 (126–153)a,b,c | 123 (104–161)b | 117 (109–129) | 120 (113–123) |
| Basal angle (degrees) | 120 (116–130) | 119 (100–134) | 118 (110–129) | 120 (107–124) |
| Occipital angle (degrees) | 126 (97–143) | 131 (100–139) | 131 (124–144) | 133 (121–142) |
| Tentorial angle (degrees) | 78 (56–100)a,b,c | 90 (65–107) | 91 (75–105) | 93 (83–106) |
| Odontoid position (mm) | 7.2 (5.2–20.7)a,b,c | −0.6 (−10.1 to 4.8) | −2.1 (−8.6 to 1.6) | −1.7 (−6.4 to −0.5) |
| Tonsillar position (mm) | 2.2 (−5.0 to 9.8) | −0.3 (−17.8 to 15.5) | 1.5 (−3.4 to 3.7) | −0.8 (−4.1 to 1.9) |
| Posterior cranial fossa volume (cm3)d |
158.8 (140.6–193.8) | 167.4 (147.8–211.4) | 175.6 (157.9–193.0) | 183.2 (161.7–216.6) |
Variables expressed as medians with absolute ranges in parentheses.
FD = fibrous dysplasia; MAS McCune-Albright syndrome.
a
Significant compared to no basilar invagination group (p < 0.05).
b
Significant compared to no craniofacial FD group (p < 0.05).
c
Significant compared to control group (p < 0.05).
d
Posterior cranial fossa volume subanalysis was performed in the following subjects: basilar invagination (n = 10), no basilar invagination (matched by age and skeletal disease burden, n = 20), no craniofacial FD (n = 10), controls (n = 8).