The effect of C1 bursting fracture on comparative anatomical relationship between the internal carotid artery and the atlas.
OBJECTIVE
To describe the effect of the C1 bursting fracture on the location of the internal carotid artery (ICA) around the atlas.


METHODS
The authors analyzed the morphology of the atlas and the ICA in 15 patients with C1 bursting fracture and compared with control group (77 patients) without any pathology. All patients were evaluated with CT angiography for the anatomical assessment. The laterality of the ICA, the distances of the ICA from the midline, anterior tubercle, and ventral surface of the C1 lateral mass were compared between two groups. The distance between the lateral margin of the longus capitis muscle and the inner edge of the transverse foramen was also measured.


RESULTS
Medially located ICA was more common in the C1 bursting fracture group than control group (76.7 vs 42.8 %). There were no significant differences between 2 groups for the distance from the midline, anterior tubercle, and ventral surface of the C1 lateral mass, respectively. The distance of the longus capitis muscle to transverse foramen was 2.52 ± 2.09 and 4.15 ± 3.09 mm in each group, and there was statistically significant difference (p < 0.01).


CONCLUSIONS
Lateral displacement of the bony structure of C1 bursting fracture changes the relative location of the ICA medially, which increase the injury risk during the bicortical C1 screw insertion. These data suggest that CT angiography or enhanced CT scans can give critical information to choose the ideal fixation technique and the proper trajectory of the screws for C1 bursting fracture.
Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, 93-6 Ji-Dong, Paldal-Gu, Suwon, Gyeonggi-do, 442-723, South Korea.
Moon Seok
MS
Kim
Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, 93-6 Ji-Dong, Paldal-Gu, Suwon, Gyeonggi-do, 442-723, South Korea.
Jun Young
JY
Kim
Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, 93-6 Ji-Dong, Paldal-Gu, Suwon, Gyeonggi-do, 442-723, South Korea.
Il Sup
IS
Kim
Department of Neurosurgery, Uijeongbu St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
Kyoung Seok
KS
Cho
Department of Neurosurgery, Bucheon St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
Sang Don
SD
Kim
Department of Neurosurgery, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
Ho Jin
HJ
Lee
Department of Neurosurgery, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
Jong Tae
JT
Kim
Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, 93-6 Ji-Dong, Paldal-Gu, Suwon, Gyeonggi-do, 442-723, South Korea. jatagi15@gmail.com.
Jae Taek
JT
Hong
D002343:Carotid Artery, Internal / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D001270:Cervical Atlas / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011859:Radiography; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging*
Anatomy; Atlas; Bursting fracture; Internal carotid artery