Vertebral artery and osseous anomalies characteristic at the craniocervical junction diagnosed by CT and 3D CT angiography in normal Czech population: analysis of 511 consecutive patients

Abstract

There are numerous indications for stabilization using instrumentation of the upper cervical spine. This area is comprised of sophisticated anatomy. There is no study describing bony and vascular anomalies of this area in the middle European population. The main aim of this study was to investigate prevalence of any vertebral artery (VA) variations and osseous anomalies in the region of the craniocervical junction in a large sample of Czech patients based on three-dimensional computed tomographic angiography (3D CTA). The VA has a variable course through C2 before it passes above its groove on the posterior arch of C1. The artery can course more medially, more posteriorly or more superiorly, thus limiting the diameter of the bony elements used as landmarks for the safe insertion of metalwork. This is known as a high-riding VA (HRVA). The VA was considered HRVA in this study if the thickness of the C2 isthmus was less than 5 mm and/or the C2 internal height was less than 2 mm and/or the width of the C2 pedicle was less than 4 mm. The prevalence of ponticulus posticus (PP) was also identified. Following the VA variations in the V3 segment of the artery were persistent first intersegmental artery (FIA), fenestration (FEN) of the VA, and the posterior inferior cerebellar artery (PICA) branch originating from the C1/2 part of VA. Records of 511 patients from our institution were analyzed. The mean age of the patients was 63.6 years. One hundred and twenty-three (24.1 %) patients were identified to have HRVA, 30 (6 %) present on both sides. The age of patient over 70 years and female sex were found to be significant risk factors for HRVA presence. The prevalence of a nearby PICA branch was 4 %, FIA was 0.4 %, and FEN was 0.2 %. The presence of PP was identified in 14.3 % of patients. The HRVA and PP are common anomalies in the Czech population, and routine preoperative high-resolution CT evaluation is mandatory to prevent the VA injury when C1-C2 instrumentation is planned. The female sex and age over 70 years were found to be the most important factors for HRVA presence. The FIA and the FEN VA were rare in our study contrary to reports published from Asia, showing as many as a 10 % the VA presence over the starting point for C1 lateral screw. On the basis of the infrequent occurrence of these anomalies, we do not recommend routine CT angiography when upper cervical spine instrumentation in the normal population is planned.

Differences in fixation strength among constructs of atlantoaxial fixation

“…In the published literature, the incidence of HRVA in the normal population ranged from 10.1% to 32%. 6,13,[24][25][26] However, the incidence increased enormously to 50%-70% in patients with AA subluxation, rheumatoid arthritis, or congenital skeletal anomalies (e.g., os odontoideum, Down syndrome, basilar invagination, and Klippel-Feil syndrome). 2,15,31,32 The issue of HRVA was particularly concerning in candidates for AA fixation, because these diseases frequently coincided with AA subluxation.…”

Proposing a new algorithm for premanipulative testing in physical therapy practice

“…The VAs join to form the basilar artery and contribute 11-20% of cerebral blood flow to the posterior circulation of the brain 30,31) . The course of the VA varies and is more likely to be anomalous in individuals with congenital deformities of the craniocervical junction or with a history of trauma involving atlantoaxial subluxation 32,33) . Up to 20% of the population has a normal anatomical variation of some type.…”

Prevalence of high-riding vertebral arteries and narrow C2 pedicles among Central-European population: a computed tomography-based study

“…Therefore, the authors decided to aid the body of neurosurgical literature and proceed with the high-quality study. Including the present paper (Klepinowski 2021*), the updated European prevalence of at least one HRVA among a total of 944 subjects [1,12] is now estimated at 24,52% (95% CI 21,83-27,32, I 2 = 0,0 [0-32,7], Cochran Q = 0,31; random-effects model) (see Fig. 3).…”