Retro-odontoid pseudotumor and subaxial spinal osteophytes: instability as the etiology and stabilization as the treatment. Illustrative cases.

backgroundRetro-odontoid pseudotumors (ROPs) and subaxial cervical osteophytes are generally considered distinct causes of ventral neural compression. The authors hypothesize that both represent secondary changes related to underlying cervical spinal instability rather than primary pathological entities. OBSERVATIONS: Between January 2022 and June 2025, 5 patients presented with coexisting ROP and multilevel subaxial osteophytes causing significant ventral dural compression. All patients underwent posterior stabilization of the atlantoaxial and involved subaxial segments aimed at achieving arthrodesis. No direct decompression, including resection of pseudotumor or osteophytes, was performed. All patients experienced immediate and sustained neurological improvement postoperatively. Follow-up imaging (≥ 6 months) demonstrated solid stabilization and regression of both ROP and osteophytes. No patient required additional decompressive surgery. LESSONS: ROP and subaxial osteophytes may represent reversible, secondary manifestations of cervical instability. Stabilization alone can result in both clinical recovery and radiographic resolution, potentially obviating the need for direct decompressive procedures. Recognition of instability as the primary pathology has important implications for surgical strategy. https://thejns.org/doi/10.3171/CASE26416.