Basilar tubercles and eminences of the clivus: Novel anatomical entities

Taweesak Tangrodchanapong; Laphatrada Yurasakpong; Athikhun Suwannakhan; Arada Chaiyamoon; Joe Iwanaga; R Shane Tubbs

doi:10.1016/j.aanat.2023.152133

Basilar tubercles and eminences of the clivus: Novel anatomical entities

Ann Anat. 2023 Oct:250:152133. doi: 10.1016/j.aanat.2023.152133. Epub 2023 Jul 17.

Authors

Taweesak Tangrodchanapong¹, Laphatrada Yurasakpong², Athikhun Suwannakhan³, Arada Chaiyamoon⁴, Joe Iwanaga⁵, R Shane Tubbs⁶

Affiliations

¹ School of Radiological Technology, Faculty of Health Science Technology, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand.
² Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand; In Silico and Clinical Anatomy Research Group (iSCAN), Bangkok, Thailand.
³ Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand; In Silico and Clinical Anatomy Research Group (iSCAN), Bangkok, Thailand. Electronic address: athikhun.suw@mahidol.edu.
⁴ Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
⁵ Department of Neurosurgery, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurology, Tulane University School of Medicine, New Orleans, LA, USA; Department of Anatomy, Kurume University School of Medicine, Fukuoka, Japan; Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA, USA.
⁶ Department of Neurosurgery, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurology, Tulane University School of Medicine, New Orleans, LA, USA; Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, USA; Department of Anatomical Sciences, St. George's University, St. George's, Grenada.

PMID: 37460045
DOI: 10.1016/j.aanat.2023.152133

Abstract

Background: The clivus forms the central skull base between the dorsum sellae and the foramen magnum. Although bony variations of the inferior surface of the clivus are well-recognized and have been well studied, studies of bony variations of the basilar (superior) surface of the clivus are scarce. Therefore, the present study was performed to investigate bony anatomical variations on the basilar part of the clivus.

Methods: Computed tomography scans belonging to 407 Indian subjects from the CQ500 open-access dataset were retrospectively reviewed.

Results: Bony tubercles on the basilar surface of the clivus were found in 40 cases (9.83%). They were classified into three types including single, double and triple. A single tubercle was found in 35 cases (8.60%) including 12 on the left (2.95%), 10 on the right (2.46%) and 13 in the center (3.19%). The tubercles were doubled in four cases (0.98%) and tripled in one case (0.25%). The average width and height of the tubercles were 4.4 ± 1.5 mm (range 1.4-7.9 mm) and 1.7 ± 0.7 mm (range 0.8-4.2 mm), respectively. Ninety-five (95%) percent of the tubercles were located on the lower half of the clivus.

Conclusions: To our knowledge, these tubercles have not been previously described. Therefore, we suggest the terms "basilar tubercles of the clivus" and "basilar eminences of the clivus", depending on their sizes. Knowledge of these newly described structures is important when interpreting radiological images of the skull base.

Keywords: Anatomical variation; Clivus; Computed tomography; Imaging; Skull; Terminology.

MeSH terms

Cranial Fossa, Posterior* / diagnostic imaging
Foramen Magnum / diagnostic imaging
Humans
Retrospective Studies
Skull Base* / diagnostic imaging
Tomography, X-Ray Computed