Abstract

The clivus is recognized as one of the most challenging areas for neurosurgeons due to its limited space and complex anatomical surroundings. This study focuses on the morphology of the extracranial clivus and its topographic relationship with adjacent vital anatomical landmarks. Conducted on 50 dry human skull bases from the Anatomy Department's Museum at our Medical College, the study measured the extracranial dimensions of the clivus. The clivus exhibited a typically triangular shape. The mean extracranial clival length was 28.46±2.52 mm. The mean width between the medial ends of the right and left foramen lacerum was 20.78±1.99 mm, while the mean width between the anterior ends of the right and left hypoglossal canals was 31.19±2.71 mm. The mean width between the anterior ends of both occipital condyles measured 15.76±2.07 mm. Additionally, the mean width between the right and left jugular foramina was 37.75±4.39 mm, and the average distance from the pharyngeal tubercle to the rostrum was 17.42±1.85 mm. The mean thickness of the clivus, measured just anterior to the pharyngeal tubercle, was 10.38±3.01 mm. This data is valuable for neurosurgeons and ENT surgeons, providing crucial insights for achieving safe access to the clivus in extracranial surgical procedures.

Key words: Basion, Chiari malformation, Dorsum sellae, Foramen lacerum, Jugular foramen, Skull base