The petrosphenoidal ligament (Gruber's ligament) extends from the petrous apex to the posterior clinoid process and forms the roof of Dorello's canal through which the abducens nerve passes. It forms the superior portion of the falciform ligament and is located at the confluence of the basilar plexus, cavernous sinus, inferior petrosal sinus, and sphenoparietal sinus. The petrolingual ligament forms the inferior portion of falciform ligament and covers the laceral segment of internal carotid artery. The length of the ligament has been reported to be between 13.2 and 13.9 mm in various studies.
Takagi and Miyamoto, describe for the first time a case involving penetration of the optic nerve and falciform ligament. In addition, to remove the anterior clinoid process in this case, the ultrasonic bone curette was a useful tool 1).