Morphometric Analysis of the Occipital Condyle and Its Surgical Implications in the Transcondylar Approach

Background: The transcondylar approach is being increasingly used to access lesions ventral to the brainstem.

Objective: To clarify the morphometric data of the occipital condyle and its importance in transcondylar approach.

Materials and Methods: Metric and morphological analysis was performed on 200 occipital condyles in 100 adult human dry skulls.

Results: The length, width, and height of the occipital condyle were found to be 23.5, 13.58, and 9.64 mm, respectively, on the right side of the skulls and 23.75, 13.62, and 9.5 mm, respectively, on the left side. The intracranial orifice of hypoglossal canal was found to be present against the junction of the second and third quarters or against the third quarter of the occipital condyle in 65%. The extracranial orifice of the hypoglossal canal was found to be present against the junction of the first and second quarters or against the second quarter of the occipital condyle in 69%.

Conclusion: The safest area to be drilled in the occipital condyle is the posterior quarter (4.5–7.8 mm from the posterior end) because there is no location for the hypoglossal canal orifice.