Comparison of MR imaging findings of nAAA subluxation patients (n = 15) and the control group (n = 20)
| MR Imaging Findings | nAAA Subluxation (%) | Control Group (%) | P Value |
|---|---|---|---|
| Dens erosion | 47 | 10 | .022 |
| Tilting of anterior atlantoaxial joint | 47 | 10 | .022 |
| Peridental effusion | 60 | 0 | < .001 |
| PD | 47 | 0 | .001 |
| RD | 27 | 0 | .026 |
| SD | 20 | 0 | NS |
| Peridental pannus | 53 | 55 | NS |
| PD | 33 | 20 | NS |
| RD | 40 | 40 | NS |
| SD | 27 | 15 | NS |
| Facet joint changea | 73 | 10 | < .001 |
| Joint space widening | 53 | 10 | .008 |
| Bone erosion | 47 | 0 | .001 |
| Joint effusion | 40 | 0 | .003 |
| Abnormal spinolaminar line | 47 | 0 | .001 |
| Focal myelopathy | 33 | 0 | .009 |
| Ligaments | |||
| Anterior atlantoaxial ligament | 13 | 15 | NS |
| Apical ligament | 53 | 30 | NS |
| Tectorial membrane | 2 | 1 | NS |
a Includes joint space widening, bone erosion, or joint effusion.