Table 1

Atlantoaxial distance (AAD) during functional radiography and functional MRI of 23 patients with chronic arthritis and unstable aAAS

RadiographyMRI
Patient NoAAD (flexion)
(mm)
AAD (extension)
(mm)
AAD (flexion)
(mm)
AAD (neutral)
(mm)
*posterior AAS; aAAS, anterior atlantoaxial subluxation.
18−5*60
2121111
312585
4125105
57−13*3−2*
610195
710288
811575
99153
106154
118076
129575
138577
148222
159276
167031
179−2*22
189477
196153
2012272
219354
2211384
23132102