Risk Factors for Subaxial Kyphosis After Posterior C1-C2 Fusion for Atlantoaxial Dislocation
Year: 2025
Type: article
Study design: Observational Study
Abstract: OBJECTIVE: The objective of this study is to evaluate the change of correlation of cervical radiologic parameters after posterior C1-C2 fusion and to identify the risk factors for postoperative subaxial kyphosis (PSK). METHODS: Medical records and radiologic data were retrospectively reviewed for patients who had undergone posterior atlantoaxial fusion for atlantoaxial dislocation at a single center from January 2014 to December 2022. Patients with previous cervical surgery, concomitant basilar invagination, or who required additional fusion extending to occipital or subaxial spine were excluded. Thirty-eight patients were included. O-C1, C1-C2, O-C2, C2-C7 cobb angles, O-C1 range of motion (ROM), T1 slope, and C2-C7 sagittal vertical axis were measured preoperatively and at one year postoperatively. RESULTS: Mean age was 54.4 years, and 24 of 38 patients were women. Rheumatoid arthritis was the most common pathology, accounting for 52.6%. Women were a significant risk factor for PSK. Patients presenting with decreased O-C1 ROM was 31.6%. The incidence of PSK was 23.7%. Preoperative cervical radiologic parameters showed the sequential linkage of significant correlation from T1 slope to O-C1 angle. However, the O-C1 angle was a valuable parameter correlated with the C2-C7 angle postoperatively. Decreased O-C1 ROM was significantly associated with PSK. The optimal postoperative C1-C2 angle ranged from 15° to 25°. CONCLUSIONS: The correlation between the upper cervical spine (O-C2 angle) and the subaxial spine (C2-C7 angle) didn't change before and after surgery. After surgery, O-C1 angle was significantly correlated with C2-C7 angle. Women, decreased O-C1 ROM, and postoperative C1-C2 angle were significantly associated with PSK.
Source: World Neurosurgery
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,943
OpenAlex ID: W4415541654