Background: Atlantoaxial instability or dislocation requires reliable posterior stabilization and fusion to prevent neurological deterioration. Although conventional Goel–Harms posterior fixation provides effective biomechanical stability, it usually requires extensive posterior cervical muscle dissection and may be associated with substantial blood loss, postoperative axial pain, and soft-tissue morbidity. Despite the advantages of minimally invasive endoscopic techniques in spinal surgery, clinical evidence regarding their application in the management of AAI/D remains limited. In this study, we report a clinical series of endoscopic-assisted atlantoaxial lateral mass fusion, provide a detailed description of the key surgical steps, and evaluate its technical feasibility, safety, and early clinical outcomes.
Methods: Sixteen patients diagnosed with AAI/D underwent endoscopic-assisted posterior atlantoaxial fusion. The procedure utilized a uniportal endoscopic system through a 2.5–3.0 cm incision, enabling direct visualization of the C1–C2 lateral mass joint, precise screw placement, and intra-articular bone grafting under continuous irrigation. Radiographic parameters, neurological function (JOA), pain (VAS), and neck disability (NDI) scores were assessed pre- and postoperatively.
Results: All surgeries were successfully completed without intraoperative neurovascular injury or hardware malposition. The mean operative time was 103.06 ± 9.55 min, and the mean blood loss was 40.06 ± 9.28 mL. The atlantodental interval (ADI) decreased from 5.14 ± 1.51 mm preoperatively to 3.37 ± 0.52 mm postoperatively (p < 0.001), and C1–C2 joint height increased from 2.98 ± 0.27 mm to 4.37 ± 0.49 mm (p < 0.001). At 3 months, bone fusion was achieved in 93.8% of patients. Clinical outcomes improved compared with preoperative values, including JOA score (8.44 ± 0.89 to 13.31 ± 1.20), VAS score (8.00 ± 0.73 to 2.25 ± 0.45), and NDI score (31.88 ± 1.93 to 12.88 ± 1.26).
Conclusion: This study introduces a novel minimally invasive technique for managing atlantoaxial instability using uniportal endoscopic-assisted posterior fusion. The combination of direct endoscopic visualization, accurate screw–rod fixation, and controlled intra-articular bone grafting offers reliable joint stabilization with reduced tissue disruption. Clinical outcomes suggest this approach may facilitate rapid recovery and improved perioperative safety, offering a valuable addition to current surgical strategies for AAI/D.
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2026 The Author(s). Orthopaedic Surgery published by Tianjin Hospital and John Wiley & Sons Australia, Ltd.
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