Issue release date: 12.11.2024
2University of Bari âAldo Moroâ, PhD Course in Tissues and Organs Transplantation and Cellular Therapies, Department of Emergency and Organ Transplantation, Bari, Italy
3Fondazione IRCCS Policlinico San Matteo, Department of Surgical Sciences, Neurosurgery Unit, Pavia, Italy
4University of Pavia, PhD School in Experimental Medicine, Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Pavia, Italy
5University of Turin, Department of Neurosciences âRita Levi Montalciniâ, Neurosurgery Unit, Turin, Italy
6Ospedale Le Molinette, Department of Neuroscience, Neurosurgery Unit, Turin, Italy
7Pediatric Neuroscience Center of Excellence, Arnold Palmer Hospital for Children, Orlando, Florida, USA DOI : 10.5137/1019-5149.JTN.26052-19.2 AIM: To identify the range of dimensional morphometric variability correlated to the basilar and condylar part of the occipital bone, which may affect the choice of approach to ventral intradural foramen magnum (FM) lesions.
MATERIAL and METHODS: In total, 25 dry skulls and 50 head computed tomography (CT) scan results have been assessed in detail, focusing on the FM, occipital condyles, jugular tubercles (JT), and hypoglossal canals (HC). A morphometric analysis has been carried out using linear and angular measurements to estimate the range of the dimensional variability of these structures. Data were presented as mean ± standard deviation, ranges, and interquartile range on a boxplot. The sagittal intercondylar angle (SICA) and anterior condylar angle (ACA) have been found to be important in estimating the axial orientation of the condyles, whereas the JTâHC interline ratio has indicated the prominence of the tubercles.
RESULTS: The SICA and ACA have exhibited high variability. The average JT-HC interline ratio was 0.8. Wider SICAâACA and higher JTâHC interline ratio make the posterolateral approach advantageous. An anterior medial or far-medial endoscopic route is indicated in opposite conditions. In this study, two illustrative cases have been reported.
CONCLUSION: A cautious preoperative morphometric evaluation of the FM region must be considered prior to using tailored and safe anterior endoscopic and posterolateral approaches to ventral intradural lesions to identify the advantages of a certain corridor as much as possible, thereby minimizing the risk of complications.
Keywords : Far-lateral approach, Foramen magnum, Jugular tubercle, Occipital condyles, Transclival approach