Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Mar 18, 2017; 8(3): 271-277
Published online Mar 18, 2017. doi: 10.5312/wjo.v8.i3.271
Role of dynamic computed tomography scans in patients with congenital craniovertebral junction malformations
Otávio Turolo da Silva, Enrico Ghizoni, Helder Tedeschi, Andrei Fernandes Joaquim
Otávio Turolo da Silva, Enrico Ghizoni, Helder Tedeschi, Andrei Fernandes Joaquim, Department of Neurology, Division of Neurosurgical, State University of Campinas, Campinas 13083-887, Brazil
Author contributions: The manuscript was written, as well data and measurements were performed by Joaquim AF and da Silva OT; the statistical analysis was made by da Silva OT; the revision of manuscript was performed by Ghizoni E and Tedeschi H; final revision was made by all authors.
Institutional review board statement: This study was approved by our Institutional Review Board in University of State Campinas, SP - Brazil (CAAE: 49070915.9.0000.5404).
Informed consent statement: This is a retrospective study that did not require informed consent statement.
Conflict-of-interest statement: The authors declare no conflicts of interest regarding this manuscript.
Data sharing statement: No data were created no data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Andrei Fernandes Joaquim, MD, Department of Neurology, Division of Neurosurgical, State University of Campinas, Tessália Vieira de Camargo Street, Campinas 13083-887, Brazil. andjoaquim@yahoo.com
Telephone: +55-19-35217478 Fax: +55-19-35217478
Received: October 9, 2016
Peer-review started: October 11, 2016
First decision: November 17, 2016
Revised: November 18, 2016
Accepted: December 16, 2016
Article in press: December 19, 2016
Published online: March 18, 2017
Processing time: 159 Days and 11.3 Hours
Abstract
AIM

To evaluate the role of dynamic computed tomography (CT) scan imaging in diagnosing craniovertebral junction (CVJ) instability in patients with congenital CVJ malformations.

METHODS

Patients with symptomatic congenital CVJ malformations who underwent posterior fossa decompression and had a preoperative dynamic CT scan in flexion and extended position were included in this study. Measurements of the following craniometrical parameters were taken in flexed and extended neck position: Atlanto-dental interval (ADI), distance of the odontoid tip to the Chamberlain’s line, and the clivus-canal angle (CCA). Assessment of the facet joints congruence was also performed in both positions. Comparison of the values obtained in flexion and extension were compared using a paired Student’s t-test.

RESULTS

A total of ten patients with a mean age of 37.9 years were included. In flexion imaging, the mean ADI was 1.76 mm, the mean CCA was 125.4° and the mean distance of the odontoid tip to the Chamberlain’s line was + 9.62 mm. In extension, the mean ADI was 1.46 mm (P = 0.29), the mean CCA was 142.2° (P < 0.01) and the mean distance of the odontoid tip to the Chamberlain’s line was + 7.11 mm (P < 0.05). Four patients (40%) had facetary subluxation demonstrated in dynamic imaging, two of them with mobile subluxation (both underwent CVJ fixation). The other two patients with a fixed subluxation were not initially fixed. One patient with atlantoaxial assimilation and C23 fusion without initial facet subluxation developed a latter CVJ instability diagnosed with a dynamic CT scan. Patients with basilar invagination had a lower CCA variation compared to the whole group.

CONCLUSION

Craniometrical parameters, as well as the visualization of the facets location, may change significantly according to the neck position. Dynamic imaging can provide additional useful information to the diagnosis of CVJ instability. Future studies addressing the relationship between craniometrical changes and neck position are necessary.

Keywords: Craniovertebral junction; Dynamic imaging; Basilar invagination; Chiari malformation; Treatment

Core tip: This study shows the importance of the dynamic image in patients with congenital craniovertebral junction anomalies. A total of ten patients with a mean age of 37.9 years were included. We could demonstrate that 40% of the patients had facetary subluxation demonstrated in dynamic imaging and two of them required surgery for craniovertebral junction due to instability. This study reported the importance of routine dynamic imaging evaluation in patients with craniovertebral junction anomalies even without evidence of instability in static computed tomography scan or magnetic resonance imaging.