Posterior Facet Distraction and Fusion Technique: Driving a Paradigm Shift in the Surgical Algorithm for Atlantoaxial Dislocation.

Abstract

Background and objectives: Atlantoaxial dislocation (AAD) remains one of the most technically challenging disorders of the craniovertebral junction. Traditional combined anterior-posterior approaches, although effective, carry substantial morbidity. The posterior facet distraction and fusion (PFDF) technique achieves reduction through sequential facet release and distraction, offering a safer posterior-only alternative. This single-center retrospective study aimed to evaluate the reduction efficacy, clinical outcomes, and safety of a PFDF-centered surgical strategy, and to develop and validate a PFDF-based treatment algorithm for AAD.

Methods: From 2017 to 2024, a total of 434 patients with AAD were surgically treated following a PFDF-based algorithm. Based on preoperative imaging, patients were classified as distractable or nondistractable according to the atlantoaxial joint condition. PFDF was performed in distractable patients without vertebral artery contraindications. Combined posterior-anterior approaches were used for patients with contraindicated vertebral artery or inadequate reduction after PFDF. Patients with rigid fusion underwent transoral odontoidectomy for ventral decompression. Clinical and radiological outcomes, complications, and fusion status were analyzed.

Results: According to the algorithm, a total of 399 patients (91.9%) achieved satisfactory reduction and decompression using PFDF alone, 12 (2.8%) required posterior fixation with anterior decompression, and 23 (5.3%) underwent transoral odontoidectomy. Significant postoperative improvement was observed in neurological and radiological outcomes ( P < .001). Anatomic reduction was achieved in 90.9% of PFDF patients, with complete bone fusion in all patients within 12 months. The overall complication rate was 5.1%, and no perioperative mortality occurred.

Conclusion: The PFDF technique provides a safe, effective, and standardized posterior approach for the management of AAD. By achieving reduction through sequential joint release and distraction, PFDF achieves high reduction and fusion rates while minimizing surgical morbidity. This method simplifies the treatment algorithm for AAD, allowing most patients to avoid anterior surgery and its associated complications.