{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T14:04:52Z","timestamp":1786716292849,"version":"build-2736575974"},"reference-count":31,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"6","license":[{"start":{"date-parts":[[2019,5,25]],"date-time":"2019-05-25T00:00:00Z","timestamp":1558742400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":["Operative Surg.","ONSURG"],"published-print":{"date-parts":[[2019,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Patients with basilar invagination and atlas occipitalization usually present abnormal anatomy of the vertebral arteries (VAs) at the craniovertebral junction (CVJ).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBJECTIVE<\/jats:title>\n                    <jats:p>To describe and further classify different types of VA variations at the CVJ with 3D visualization technology.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>One hundred twenty patients with basilar invagination and atlas occipitalization who had undergone 3-dimensional computed tomographic angiography (3D-CTA) were retrospectively studied. Imaging data were processed via the separating, fusing, opacifying, and false-coloring-volume rendering technique. Abnormal anatomy of the VA at the CVJ was categorized and related anatomic parameters were measured.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>Seven different types were classified. Type I, VAs enter the cranium after leaving VA groove on the posterior arch of atlas (26.7% of 240 sides); Type II, VAs enter an extraosseous canal created in the assimilated atlas lateral mass-occipital condyle complex before reaching the cranium (53.3%); Type III, VA courses above the axis facet or curves below the atlas lateral mass then enter the cranium (11.7%); Type IV, VAs enter the spinal canal under the axis lamina (1.3%); Type V, high-riding VA (31.3%); Type VI, fenestrated VA (2.9%); Type VII, absent VA (4.2%). Distance from the canal of Type II VA to the posterior facet surface of atlas lateral mass (5.51\u00a0\u00b1\u00a02.17 mm) means a 3.5-mm screw can be safely inserted usually. Shorter distance from the midline (13.50\u00a0\u00b1\u00a04.35) illustrates potential Type III VA injury during exposure. Decreased height and width of axis isthmus in Type V indicate increased VA injury risks.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSION<\/jats:title>\n                    <jats:p>Seven types of VA variations were described, together with valuable information helpful to minimize VA injury risk intraoperatively.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ons\/opz076","type":"journal-article","created":{"date-parts":[[2019,5,25]],"date-time":"2019-05-25T05:00:18Z","timestamp":1558760418000},"page":"594-602","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":22,"title":["Three-Dimensional Evaluation and Classification of the Anatomy Variations of Vertebral Artery at the Craniovertebral Junction in 120 Patients of Basilar Invagination and Atlas Occipitalization"],"prefix":"10.1227","volume":"17","author":[{"given":"Teng","family":"Li","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi-heng","family":"Yin","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guang-yu","family":"Qiao","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hua-wei","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin-guang","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2019,12]]},"reference":[{"issue":"3","key":"bib1-20240909","doi-asserted-by":"crossref","first-page":"E170","DOI":"10.1097\/BRS.0b013e318227efe7","article-title":"Three-dimensional configuration and morphometric analysis of the lateral atlantoaxial articulation in congenital anomaly with occipitalization of the atlas","volume":"37","author":"Yin","year":"2012","journal-title":"Spine"},{"issue":"6","key":"bib2-20240909","doi-asserted-by":"crossref","first-page":"528","DOI":"10.1055\/s-0035-1566225","article-title":"Vertebral artery injury during routine posterior cervical exposure: case reports and review of literature","volume":"5","author":"Molinari","year":"2015","journal-title":"Global Spine J"},{"issue":"4","key":"bib3-20240909","doi-asserted-by":"crossref","first-page":"634","DOI":"10.3171\/jns.1998.88.4.0634","article-title":"Vertebral artery injury in C1-2 transarticular screw fixation: results of a survey of the AANS\/CNS section on disorders of the spine and peripheral nerves. 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