We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Influence Of Atlantoaxial Fusion On Sagittal Alignment Of Occipitocervical And Subaxial Spines In Os Odontoideum With Reducible Atlantoaxial Instability.
- Authors
Park, Jong-Beom; Park, Eric Taejin; Byung-Wan Choi; Jong-Won Kang; Han Chang
- Abstract
Introduction: In our experience, sagittal malalignment, such as kyphosis or loss of lordosis, occurs at occipitocervical and subaxial spines following atlantoaxial fusion. However, little information is available about the effect of C1-C2 angle on sagittal malalignment of C0-C1 and C2-C7. We hypothesized that the severity of the sagittal malalignment of C0-C1 and C2-C7 increases with the increase in the C1-C2 angle. Material and Methods: We retrospectively reviewed 21 patients (10 females and 11 males) who achieved solid atlantoaxial fusion for reducible atlantoaxial instability (AAI) secondary to Os odontoideum. Nonunion cases were excluded from this study. The mean age at the time of surgery was 42.8 (range, 5-73) years, and the mean follow-up duration was 4.9 (range, 2-12) years. Eleven patients with anterior AAI underwent posterior sublaminar wiring alone, and 10 patients with combined AAI underwent posterior sublaminar wiring and transarticular screw fixation. Radiographic parameters were measured before surgery and at the final follow-up. C0-C1, C1-C2, and C2-C7 angles were measured on neutral lateral radiographs. Ranges of motion (ROMs) at C0-C1, C1-C2, and C2-C7 during flexion and extension were measured on lateral radiographs. Patients were divided into two groups according to the final C1-C2 angle. The final C1-C2 angle was ≥22° in group A (N = 11) and <22° in group B (N = 11). Differences in radiographic parameters between the groups were evaluated. Results: At the final follow-up, the C1-C2 angle was increased, but this increase was not statistically significant (18° compared with 22°, p = 0.097). In contrast, the C0-C1 (10° compared with 5°, p < 0.05) and C2-C7 (22° compared with 13°, p < 0.05) angles were significantly decreased. The final C1-C2 angle was negatively correlated with the final C0-C1 (correlation coefficient, -0.547; p < 0.05) and C2-C7 (correlation coefficient, -0.705, p < 0.01) angles. The final C0-C1 (3.8° compared with 6.2°) and C2-C7 (7.7° compared with 20°) angles were smaller in group A than in group B (both p < 0.05). After atlantoaxial fusion, ROMs at C0-C1 (17° compared with 9°, p < 0.05) and C2-C7 (39° compared with 31°, p < 0.05) were significantly decreased. Conclusion: We found that lordosis of occipitocervical and subaxial spines following atlantoaxial fusion was negatively associated with the final C1-C2 angle, along with decreased ROM. We are currently attempting to fuse the C1-C2 angle at <22° in order to decrease the likelihood of sagittal malalignment of occipitocervical and subaxial spines.
- Publication
Global Spine Journal, 2018, Vol 8, p200S
- ISSN
2192-5682
- Publication type
Article
- DOI
10.1177/2192568218771072