Surgical treatment and clinical outcome in non-inflammatory atlantoaxial degeneration and retro-odontoid pseudotumor.

Introduction: Patients suffering from atlantoaxial degeneration with spinal cord compression may suffer from burdening neck pain and myelopathy, reducing their mobility and quality of life. Formerly known as a distinct entity in rheumatoid arthritis, atlantoaxial degenerative arthrosis with or without atlantoaxial instability and spinal cord compression may occur without being caused by autoimmune or inflammatory factors. Research question: This study aims to evaluate the outcome of C1-2 fusion in patients with atlantoaxial degeneration. Material and methods: We retrospectively assessed patients undergoing C1-2 stabilization for symptoms and radiographical signs of atlantoaxial degeneration with or without a retrodental mass in our neurosurgical department from January 2012 to December 2023. Patients with inflammatory and autoimmune diseases were excluded. Radiological parameters, surgical data, and clinical follow-up data were retrieved from our records to investigate the clinical outcome. Results: We included 43 patients suffering from refractory neck pain and/or myelopathy for further analysis. The mean age was 73 years. All patients underwent C1-2 fixation and 60.5 % obtained a decompression via C1 laminectomy for myelopathy. Median mJOA score improved significantly from 12/18 preoperatively to 14/18 at a median follow-up of nine months. The mean preoperative atlantodental distance was 2.5 mm. In total, pain relief was achieved in 93.5 % of the patients, and 90.5 % of the patients with preoperative myelopathy improved on the mJOA scale at follow-up. Discussion and conclusion: C1-2 fusion achieved satisfying results in patients suffering from non-inflammatory atlantoaxial degeneration. Patients suffering from neck pain and symptoms of myelopathy improved until follow-up with the posterior approach.