Clinical and Radiographic Results of Atlantoaxial Interfacetal Fusion Using Local Bone with Fixation: Does the Joint Cartilage Debridement Matter?

Purpose: To evaluate the safety and effectiveness of atlantoaxial interfacetal fusion with local bone autografting combined with posterior internal fixation for treating patients with atlantoaxial instability (AAI) or reducible atlantoaxial dislocation (AAD). Methods: Patients with AAI or reducible AAD who underwent surgery using C1-2 fixation and interfacetal bone fusion in our institution from March 2020 to June 2022 were retrospectively reviewed. According to whether articular cartilage was scraped and the joint was decorticated during surgery, the patients were divided into the scraped (S) group and the non-scraped (NS)group. The granular bone harvested from the C2 spinous process, lamina, and tubercula posterius was packed into the atlantoaxial joint. Clinical and radiographic outcomes were assessed. Results: We recruited 57 patients with > 2 year of follow-up and an average age of 42.32±17.56years. The operations were successfully performed in all patients without any intraoperative complications. The mean operation duration was 123.11±37.24 min, and the average blood loss was 129 ± 61 mL. At the final follow-up, all patients (100%) achieved anatomic atlantoaxial reduction (ADI<3 mm), and solid atlantoaxial fusion. Compared with preoperation, ADI decreased from 7.11±2.34 to 1.57±0.74 mm (P<0.01), and the cervicomedullary angle increased from 134.88°±13.74° to 146.46°±11.14° (P<0.01), and the average JOA score significantly improved from 13.05±1.93 to 15.46±1.48 at the final follow-up (P<0.01) at the final follow-up. Conclusions: Atlantoaxial interfacetal fusion using local bone graft was an efficient and safe surgical procedure for treating patients with AAI or reducible AAD, even if the atlantoaxial joint cartilage debridement and surface decortication were not performed.