Differences in Cross-Sectional Intervertebral Foraminal Area From C3 to C7.

Area of Science:

• Anatomy
• Orthopedics
• Radiology

Background:

• Few studies have quantified cervical foraminal areas in the absence of degenerative changes.
• Understanding normal anatomy is essential for diagnosing pathologies affecting the cervical spine.

Purpose of the Study:

• To determine and compare mean cross-sectional foraminal areas at C3/4, C4/5, C5/6, and C6/7 levels.
• To analyze differences in foraminal areas based on sex and race in a non-pathological sample.

Main Methods:

• Anatomical study of 100 skeletally mature osseous specimens (ages 20-40).
• Equal representation of African American and Caucasian males and females (n=25/group).
• Digital measurement of foraminal dimensions and calculation of cross-sectional areas using an elliptical model.

Main Results:

• The C4/5 foramen was significantly smaller than C5/6 (P < .001).
• The C5/6 foramen was significantly narrower than C6/7 (P < .001), with and without disc augmentation.
• African Americans exhibited smaller foraminal sizes compared to Caucasians; no sex-based differences were observed.

Conclusions:

• This study provides the largest anatomical reference for the non-pathological cervical intervertebral foramen.
• Findings indicate a specific narrowing pattern (C4/5 < C5/6 < C6/7) in healthy adult spines.
• Knowledge of these relative foraminal areas aids in understanding degenerative conditions and pathologies impacting the cervical spine.