Cervical Sagittal Alignment in Patients With Basilar Invagination

Area of Science:

• Orthopedics
• Neurosurgery
• Radiology

Background:

• Cervical sagittal alignment is crucial but debated, especially in congenital deformities.
• Literature primarily describes acquired cervical diseases, with limited focus on congenital cervical spine deformities like basilar invagination (BI).

Purpose of the Study:

• To create a morphological map of cervical sagittal alignment in basilar invagination (BI).
• To enhance understanding of cervical sagittal alignment in congenital cervical deformities.
• To identify key parameters differentiating BI patients from asymptomatic individuals.

Main Methods:

• Retrospective analysis of cervical spine lateral radiographs.
• Inclusion of 87 BI patients and 98 asymptomatic subjects.
• Assessment of cranial, cervical spine, and thoracic inlet parameters.

Main Results:

• BI patients exhibited significantly larger cranial tilt, C2-C7 angle, and cervical tilt.
• BI patients showed significantly smaller cranial slope, C0-C2 angle, C0-C7 angle, and thoracic inlet angle.
• Sagittal vertical axis C2-C7 was strongly correlated with other parameters and smaller in BI patients with fusion.

Conclusions:

• Significant differences in cervical sagittal alignment exist between BI patients and asymptomatic individuals.
• BI patients present with forward/downward cranial tilt, reduced upper cervical lordosis, increased lower cervical lordosis, and a smaller thoracic inlet angle.
• Cervical spine alignment, particularly thoracic inlet alignment, is closely associated with cranial alignment in both BI patients and the general population.