Ossified ligaments in relation to foramina and bony landmarks of the middle cranial fossa

Introduction

Sporadic reports on individual ossified ligaments of the middle cranial fossa (MCF) fail to do justice to their grave clinical consequences. The present study attempts a comprehensive search for all ossified ligaments and associated accessory foramina in relation to MCF, in order to standardize baseline prevalence pertinent for the Indian subcontinent.

Methods

Fifty well-preserved and intact, adult (age >20 yrs), dry, macerated skulls were obtained from the Anatomy departments of medical colleges in Delhi, including the All India Institute of Medical Sciences. All the skulls were subjected to a meticulous, bilateral examination and digital photography of internal & external aspects of the skull base, to look for presence of partially or completely ossified ligaments and resulting accessory foramina.

Results

The incidence values recorded from the present sample (n = 50 × 2) for completely (C) and incompletely (IC) ossified MCF ligaments are as follows: Caroticoclinoid: C = 6 (6%), IC = 2 (2%); Interclinoid: C = 3 (3%), IC = 2 (2%); Pterygospinous: C = 2 (2%), IC = 3 (3%); Pterygoalar: C = 1 (1%), IC = 2 (2%); Petrosphenoid/petroclinoid: C = 2 (2%), IC = 0 (0%). All completely ossified ligaments were found to be associated with accessory foramina.

Discussion

Presence of ossified MCF ligaments cannot be overlooked in patients with symptoms arising from compression of neurovascular structures and those undergoing skull-base neurosurgery, necessitating pre-surgical screening for presence of calcified ligaments in close proximity to vital structures ? a scenario that may influence surgical outcome.