Basilar invagination, Chiari malformation, syringomyelia: a review

Area of Science:

• Neurosurgery
• Orthopedic Surgery
• Radiology

Background:

• Basilar invagination is a complex craniovertebral junction pathology.
• Over 3300 patients with craniovertebral junction pathology were reviewed over decades.
• Categorization based on instability is crucial for understanding pathogenesis.

Purpose of the Study:

• To review experience with basilar invagination.
• To categorize patients based on craniovertebral junction instability.
• To establish a basis for rational surgical treatment.

Main Methods:

• Review of institute and personal experience (25+ years).
• Analysis of 3300 patients with craniovertebral junction pathology.
• Classification into Group A (instability present) and Group B (instability absent) using Chamberlain's parameters.

Main Results:

• Group A basilar invagination pathogenesis linked to mechanical instability.
• Group B basilar invagination pathogenesis linked to embryonic dysgenesis.
• Facetal distraction and lateral mass fixation effective for Group A, avoiding decompression surgery.

Conclusions:

• Differentiating basilar invagination by instability offers pathogenic insights.
• Facetal distraction and lateral mass fixation are effective for unstable basilar invagination.
• Foramen magnum decompression is a rational treatment for Group B basilar invagination.