Abstract
Introduction
Few studies have evaluated the outcomes following C1–C2 fusion for atlanto–axial osteoarthritis (AAOA). Previous studies in rheumatoid arthritis (RA) patients with atlanto–axial instability have demonstrated unexpected development of subaxial kyphosis following C1–C2 fusion; however, this complication in patients with AAOA remains unknown. Therefore, we set out to evaluate the subaxial cervical sagittal alignment following C1–C2 fusion for AAOA.
Methods
We performed a retrospective review of all patients following C1–C2 fusion from a single center, single-surgeon from 2002 to 2012. All charts, records, and imaging studies were reviewed for each case, and preoperative, immediate postoperative, and final follow-up plain films were evaluated. Patients were divided into three diagnosis categories for further comparison: AAOA, rheumatoid, and trauma.
Results
A total of 29 patients were included in the review, with an average radiographic follow-up of 38 months. There were 14 patients with AAOA, 4 patients with RA/gout (1 gout patient with C1–C2 pannus causing spinal cord compression), and 11 patients treated for a traumatic etiology. Overall, we found that patients with AAOA did not have a significant change in subaxial sagittal alignment from preoperative to final follow-up (−11.7 to −13.8 degrees, p = 0.23, [− degrees] = lordosis, [+ degrees] = kyphosis), which was similar in the trauma group (−9.7 to −8.4 degrees, p = 0.47). This was comparable to the RA/gout group that demonstrated a significant change in sagittal alignment from −20.5 to −0.2 degrees (p = 0.04).
Conclusion
Our study demonstrates that patients with nonrheumatologic conditions (AAOA and trauma) undergoing C1–C2 fusion do not develop postoperative subaxial cervical kyphosis. We postulate that the loss of subaxial lordosis in the rheumatologic patients may be a function of their underlying systemic disease.