Turkish Neurosurgery 2019 , Vol 29 , Num 2
Radiological and Surgical Anatomy of Ventral C1-C2 Complex
Sibel CIRPAN1,Salih SAYHAN1,Goksin Nilufer YONGUC1,Canan EYUBOGLU1,Nuri KARABAY3,Mustafa GUVENCER1,Sait NADERI4
1Dokuz Eylul University, School of Medicine, Department of Anatomy, Izmir, Turkey
2Private Medigunes Hospital, Neurosurgery Clinic, Manisa, Turkey
3Dokuz Eylul University, School of Medicine, Department of Radiodiagnostics, Izmir, Turkey
4Health Sciences University, Umraniye Education and Research Hospital, Department of Neurosurgery, Istanbul, Turkey
DOI : 10.5137/1019-5149.JTN.23499-18.1 AIM: To evaluate anatomical data of the bony structures during exploration of the C1-C2 complex.

MATERIAL and METHODS: This study included six formalin-fixed cadaveric head and neck specimens. Radiological images and anatomical measurements included: C1-C2 distance, bony distance between C1 anterior tubercle-nares and superior incisors, height of C1 anterior arch, and height and width of odontoid articular surface.

RESULTS: The mean distance between C1 anterior tubercle-nares and superior incisors on maxilla were 96.16 ± 8.07 mm and 84.14 ± 9.16 mm, respectively. The mean height of C1 anterior arch was 13.89 mm. The meandistance between medial borders of right-left C1 lateral masses was 19.10 ± 1.80 mm. The mean distance between medial border of lateral midline on mass right and left sides were 9.43 ± 0.88 mm and 9.68 ± 0.97 mm, respectively. The mean height of C1 anterior arch at midline was 13.89 ± 2.48 mm, and the mean distance between ventral surface of anterior arch and ventral joint of odontoid at midline was 6.43 ± 1.29 mm. The anteroposterior, horizontal diameters of odontoid on its base were 12.12 ± 0.38 mm, and 11.12 ± 0.94 mm, respectively. The angles of transoral and transnasal approaches to C1 were 32.67 ± 4.59° and 32.00 ± 2.10°, respectively.

CONCLUSION: A safe transoral or transnasal odontoidectomy requires accurate measurements and imaging regarding ventral C1-C2 relationships, distances of odontoid, lateral mass and midline. Keywords : Atlantoaxial complex, Radiological anatomy, Surgical anatomy, Odontoidectomy, Cadaveric study

Corresponding author : Mustafa GUVENCER, mustafa.guvencer@gmail.com