Year: 2026
Type: article
Abstract: Background. Kimmerle anomaly is an anatomical variant of the atlas characterized by formation of a partial or complete osseous bridge over the vertebral artery groove on the posterior arch of C1. Initially regarded predominantly as an anatomical and radiographic curiosity, the anomaly subsequently attracted clinical interest because of its close relationship with the V3 segment of the vertebral artery, the suboccipital nerve, and the surgical anatomy of the craniovertebral junction. Materials and Methods. A structured narrative review of classical and contemporary publications addressing the historical description, terminology, epidemiology, morphological classification, radiological evaluation, vascular relationships, and surgical relevance of Kimmerle anomaly was performed. Historical anatomical and radiographic studies were compared with modern CT, CT angiographic, morphometric, systematic-review, and meta-analytic evidence. Results. Concepts regarding Kimmerle anomaly evolved from recognition of an anatomical bony bridge to radiographic identification, epidemiological characterization, morphological classification, appreciation of C1 instrumentation-related risk, and, more recently, assessment of potential dynamic neurovascular conflict. Classification systems progressed from simple complete/incomplete forms to laterality-based, morphometric, and vascularly oriented phenotypes. Contemporary evidence emphasizes that morphological presence alone does not demonstrate symptom causality. Conclusion. The concept of Kimmerle anomaly has evolved from a simple atlas variant into a patient-specific craniovertebral phenotype with morphological, vascular, neurological, and surgical dimensions. Contemporary clinical interpretation requires separation of incidental anatomy from surgically significant morphology and dynamically verified symptomatic neurovascular conflict.
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7222197026