Interdisciplinary Neurosurgery · Published 2026-07-14 · DOI 10.1016/j.inat.2026.102316
Kenneth James, James Austin Helton, Samuel D. Macomson, Michel Paré, Shannon Derthick, Fernando L. Vale
Objective: Atlantoaxial synovial cysts (SCAA) are rare lesions that may cause compressive myelopathy. While direct cyst excision has been the traditional approach, growing evidence supports posterior fusion alone as a means of achieving both neurological recovery and cyst regression. This study presents a case series, a structured literature review, and a novel classification system to guide surgical decision-making. Methods: Three patients with symptomatic SCAA underwent posterior C1–C2 fusion without direct cyst resection. Clinical outcomes and radiographic cyst evolution were evaluated. A structured literature review identified 98 reported cases, of which 57 had imaging adequate for analysis. Lesions were classified by vertical location relative to the C1 arch using a four-tier system. The classification system was constructed as a descriptive framework to allow anatomical comparison across published reports and not a validated predictive model. Surgical strategy and outcomes were analyzed according to cyst type. Results: All three patients experienced neurological improvement, with postoperative imaging confirming near complete-to-complete cyst regression. Literature review demonstrated that posterior fusion alone was frequently effective for Type I and Type III lesions, whereas Type II lesions more often involved direct decompression due to compression of the brainstem. Conclusion: Posterior fusion without direct cyst excision can be an effective and less invasive treatment for many cases of SCAA. The proposed classification system may assist in preoperative planning by correlating lesion location with observed treatment patterns, although further validation is required. This stabilization-first approach addresses the underlying instability thought to drive cyst formation and may reduce the need for more invasive anterior or transdural procedures.
Abstract from DOAJ. Public domain (CC0 1.0).
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James, K., Helton, J., Macomson, S., et al. (2026). Atlantoaxial synovial cysts: a stabilization-first paradigm for surgical management. Interdisciplinary Neurosurgery. https://doi.org/10.1016/j.inat.2026.102316