Outcomes Following Arthrodesis for Atlanto-Axial Osteoarthritis

Study Design. Retrospective analysis. Objective. We set out to evaluate the radiographic and patient-reported outcomes following C1-C2 arthrodesis for atlantoaxial osteoarthritis (AAOA) using modern instrumentation and techniques. Summary of Background Data. Few studies have evaluated outcomes following C1-C2 arthrodesis for AAOA using modern surgical fixation techniques. Methods. Retrospective analysis of all patients following C1-C2 arthrodesis with recalcitrant AAOA from a single center, single surgeon from 2002 to 2012. Preoperative, immediate and final follow-up postoperative radiographic images were evaluated. Patient-reported outcomes scores were assessed preoperative, 1-year, and final postoperative follow-up. Results. We found a total of 14 patients (13 female, 1 male) with average follow-up of 2.96±2.26 years and mean age at surgery of 71.8±9.3 years old. The most common construct was posterior C1-C2 bilateral screw-rod construct (SRC) (n=9), and there were 3 patients with transarticular screw (TAS) constructs, and 2 patients with hybrid fixation (unilateral SRC and contralateral TAS). Mean change from baseline to final follow-up for Numeric Pain Rating Scale (NRS) was-4.7±2.1, and Neck Disability Index (NDI) was-21.0±13.6, with 11 (78.6%) patients demonstrated a substantial clinical benefit (change in NDI≥10). There were no differences from baseline to all follow-up time points for SF-12 Physical and Mental Component Scores. All patients had evidence of solid C1-C2 arthrodesis and stable fixation at final follow-up, with no significant change in subaxial sagittal alignment. There were no perioperative or postoperative complications. Conclusion. We report one of the largest series evaluating patient-reported outcomes in patients following arthrodesis for AAOA using modern C1-C2 fixation techniques. Our study found C1-C2 arthrodesis for AAOA to be safe and effective, with a significant improvement in patient-reported pain and neck disability and most patients reporting substantial clinical benefit.