Basilar invagination without atlantoaxial dislocation: treatment by correction of clivus canal angle with interfacet distraction and fixation

Table 3 Statistical outcomes in 19 patients

Variable	Pre-mean Value^a	Post-mean value		Two-tailed Wilcoxon signed-rank test
Variable	Pre-mean Value^a	2 weeks^b	the latest^c	Two-tailed Wilcoxon signed-rank test
CCA°	129.34 ± 8.52°	139.75 ± 8.86°	139.75 ± 8.86°	< 0.001
pB-C2 (mm)	7.47 ± 2.21	5.68 ± 3.13	5.68 ± 3.13	= 0.002
JOA	12.32 ± 1.89	14.37 ± 1.30	14.58 ± 1.26	< 0.001

JOA Japanese Orthopedic Association scores, CCA Clivus-canal angle, pB-C2, The length of a perpendicular line extending from another line drawn from the basion to the dorsal-caudal aspect of the C2 body on sagittal CT images
^a,b,cThe mean value of CCA, pB-C2, and JOA at different times

ISSN: 1471-2474