Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study
Study Design: This was an interventional human cadaver study and radiological study. Objectives: Atlas instrumentation is frequently involved in fusion procedures involving the craniocervical junction area. Identification of the entry point at the center of atlas lateral mass (ALM) is challenging be...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2017-01-01
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| Series: | Journal of Craniovertebral Junction and Spine |
| Subjects: | |
| Online Access: | http://www.jcvjs.com/article.asp?issn=0974-8237;year=2017;volume=8;issue=2;spage=97;epage=102;aulast=Al-Habib |
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| author | Amro F Al-Habib Abdulkarim Al-Rabie Sami Aleissa Abdulrahman Albakr Abdulaziz Abobotain |
| author_facet | Amro F Al-Habib Abdulkarim Al-Rabie Sami Aleissa Abdulrahman Albakr Abdulaziz Abobotain |
| author_sort | Amro F Al-Habib |
| collection | DOAJ |
| description | Study Design: This was an interventional human cadaver study and radiological study.
Objectives: Atlas instrumentation is frequently involved in fusion procedures involving the craniocervical junction area. Identification of the entry point at the center of atlas lateral mass (ALM) is challenging because of its rounded posterior surface and the surrounding venous plexus. This report examines using the medial edge of atlas posterior arch (MEC1) as a fixed and reliable anatomic reference to guide the entry point of ALM screws.
Methods: Fifty, normal, cervical spine computed tomography studies were reviewed. ALM screw trajectories were planned at one point along MEC1 and another point 2 mm lateral to MEC1. Free-hand ALM instrumentation was performed in ten fresh human cadavers using the 2 mm entry point, with a sagittal trajectory parallel to atlas inferior arch (IAC1); three-dimensional imaging was then performed to confirm instrumentation accuracy.
Results: The average ALM diameter was 12.35 mm. Inserting a screw using the entry point 2 mm lateral to MEC1 was closer to ALM midpoint than using the entry point along MEC1 (P < 0.0001). Twenty ALM screws were successfully inserted in the ten cadavers. No encroachments into the spinal canal or foramen transversarium occurred. However, two screws were superiorly directed and violated the occipitocervical joint; they were not parallel to IAC1.
Conclusion: MEC1 provides a fixed and reliable landmark for ALM instrumentation. An entry point 2 mm point lateral to MEC1 is close to ALM midpoint. IAC1 also provides a guide for the sagittal trajectory. Attention to anatomic landmarks may help reduce complications associated with atlas instrumentation but should be verified in future clinical studies. |
| first_indexed | 2024-12-12T22:09:19Z |
| format | Article |
| id | doaj.art-f3be49adf419425ab04c3ccf08449894 |
| institution | Directory Open Access Journal |
| issn | 0974-8237 |
| language | English |
| last_indexed | 2024-12-12T22:09:19Z |
| publishDate | 2017-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Journal of Craniovertebral Junction and Spine |
| spelling | doaj.art-f3be49adf419425ab04c3ccf084498942022-12-22T00:10:17ZengWolters Kluwer Medknow PublicationsJournal of Craniovertebral Junction and Spine0974-82372017-01-01829710210.4103/jcvjs.JCVJS_36_17Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic studyAmro F Al-HabibAbdulkarim Al-RabieSami AleissaAbdulrahman AlbakrAbdulaziz AbobotainStudy Design: This was an interventional human cadaver study and radiological study. Objectives: Atlas instrumentation is frequently involved in fusion procedures involving the craniocervical junction area. Identification of the entry point at the center of atlas lateral mass (ALM) is challenging because of its rounded posterior surface and the surrounding venous plexus. This report examines using the medial edge of atlas posterior arch (MEC1) as a fixed and reliable anatomic reference to guide the entry point of ALM screws. Methods: Fifty, normal, cervical spine computed tomography studies were reviewed. ALM screw trajectories were planned at one point along MEC1 and another point 2 mm lateral to MEC1. Free-hand ALM instrumentation was performed in ten fresh human cadavers using the 2 mm entry point, with a sagittal trajectory parallel to atlas inferior arch (IAC1); three-dimensional imaging was then performed to confirm instrumentation accuracy. Results: The average ALM diameter was 12.35 mm. Inserting a screw using the entry point 2 mm lateral to MEC1 was closer to ALM midpoint than using the entry point along MEC1 (P < 0.0001). Twenty ALM screws were successfully inserted in the ten cadavers. No encroachments into the spinal canal or foramen transversarium occurred. However, two screws were superiorly directed and violated the occipitocervical joint; they were not parallel to IAC1. Conclusion: MEC1 provides a fixed and reliable landmark for ALM instrumentation. An entry point 2 mm point lateral to MEC1 is close to ALM midpoint. IAC1 also provides a guide for the sagittal trajectory. Attention to anatomic landmarks may help reduce complications associated with atlas instrumentation but should be verified in future clinical studies.http://www.jcvjs.com/article.asp?issn=0974-8237;year=2017;volume=8;issue=2;spage=97;epage=102;aulast=Al-HabibAtlantoaxial instrumentationatlas instrumentationatlas lateral massatlas medial archC1 inferior arch bordercraniocervical instrumentation |
| spellingShingle | Amro F Al-Habib Abdulkarim Al-Rabie Sami Aleissa Abdulrahman Albakr Abdulaziz Abobotain Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study Journal of Craniovertebral Junction and Spine Atlantoaxial instrumentation atlas instrumentation atlas lateral mass atlas medial arch C1 inferior arch border craniocervical instrumentation |
| title | Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study |
| title_full | Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study |
| title_fullStr | Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study |
| title_full_unstemmed | Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study |
| title_short | Atlas instrumentation guided by the medial edge of the posterior arch: An anatomic and radiologic study |
| title_sort | atlas instrumentation guided by the medial edge of the posterior arch an anatomic and radiologic study |
| topic | Atlantoaxial instrumentation atlas instrumentation atlas lateral mass atlas medial arch C1 inferior arch border craniocervical instrumentation |
| url | http://www.jcvjs.com/article.asp?issn=0974-8237;year=2017;volume=8;issue=2;spage=97;epage=102;aulast=Al-Habib |
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