- Department of Neurosurgery and Spine Surgery, Iseikai Hospital, Osaka, Japan
- Graduate School of Health Care Sciences, Jikei Institute, Osaka, Japan
Graduate School of Health Care Sciences, Jikei Institute, Osaka, Japan
DOI:10.4103/2152-7806.148032Copyright: © 2014 Sasaki M. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
How to cite this article: Sasaki M, Matsumoto K, Tsuruzono K, Yoshimura K, Shibano K, Yonenobu K. Anterior transarticular screw fixation as a conventional operation for rigid stabilization. Surg Neurol Int 30-Dec-2014;5:
How to cite this URL: Sasaki M, Matsumoto K, Tsuruzono K, Yoshimura K, Shibano K, Yonenobu K. Anterior transarticular screw fixation as a conventional operation for rigid stabilization. Surg Neurol Int 30-Dec-2014;5:. Available from: http://sni.wpengine.com/surgicalint_articles/anterior-transarticular-screw-fixation-conventional-operation-rigid-stabilization/
Background:Anterior transarticular screw (ATS) fixation is a useful surgical option for atlantoaxial (AA) stabilization. This report presents a revised ATS method for AA fusion.
Methods:A 79-year-old male presented with AA instability attributed both to an old odontoid fracture and severe degeneration of the lateral atlantoaxial joints (LAAJs). ATS fixation was performed through the conventional anterior cervical approach. The longest screw trajectories were planned preoperatively using multiplanar reconstruction computed tomography (CT) scans, with entry points of the screws situated at the midpoint on the inferior border of the axial body. The surgical exposure was limited to opening at the entry points alone. Our retractor of choice was the Cusco speculum; it sufficiently secured space for utilizing the required instruments for screw placement while offering sufficient protection of soft tissues. Cannulated full-threaded bicortical screws stabilized the LAAJs. Screw insertion required a significant amount of coronal angulation up to the superior articular process of the atlas under open-mouth and lateral fluoroscopy image guidance. After ATS fixation, bone grafting was performed between the posterior laminae of the axis and the atlas through a conventional posterior approach.
Results:Bony fusion between the atlas and the axis was confirmed radiographically. Arthrodesis of the LAAJs occurred despite no bone grafting.
Conclusions:Rigid fixation of the LAAJs was obtained by our ATS technique, indicating that it is an alternative method for AA fixation when posterior rigid internal fixation is not applicable.
Keywords: Anterior transarticular screw fixation, atlantoaxial instability, facet degeneration, odontoid fracture
Anterior transarticular screw (ATS) fixation is a useful surgical option for atlantoaxial (AA) stabilization. Here, we report a patient with an old odontoid fracture and severe degenerative changes of the lateral atlantoaxial joints (LAAJs) who was treated successfully with ATS fixation. Our method included the utilization of conventional surgical techniques plus rigid stabilization to attain solid fusion between the atlas and the axis.
A 79-year-old male presented with progressive severe myelopathy. On admission, his Japanese Orthopedic Association (JOA) score was 6/17. X-ray studies confirmed severe AA instability, while the computed tomography (CT) showed marked cord compression and AA subluxation secondary to an old odontoid fracture, lateral dislocation of the axis, and severe degeneration of both LAAJs [
Preoperative computed tomography (CT) scans. a Coronal image shows old odontoid fracture, lateral dislocation of the atlas on the axis, and severe degeneration of the lateral atlantoaxial joints. b-e CT myelograms in a flexion-extension study shows that spinal cord compression was induced by atlantoaxial subluxation (AAS) in neck flexion (b, c) and that the compression was released by correction of the AAS in neck extension (d, e)
Following these examinations, the patient's neck was fixed in extension utilizing a halo vest; this corrected the AA alignment. ATS fixation was chosen due to the high-riding VA and because the AA subluxation was corrected in extension.
Screw trajectories were planned preoperatively using multiplanar reconstruction CT scans [
Preoperative planning for screw trajectories using multiplanar reconstruction CT scans. Serial symmetrical coronal sections were created from the midpoint on the inferior border of the axial body. We found a section that enabled the longest screw pathways (black arrows) (a). The sagittal angulation of the section on the scout image (white line) presented a direction of screw insertion in the sagittal plane (b)
Using a standard anterior cervical approach, the vertebral bodies of the middle cervical spine were exposed. Blunt dissection then proceeded cranially along the anterior surface up to the C2-3 intervertebral disc. A Cusco speculum was placed to secure the operative field. Under biplanar fluoroscopy image guidance, a Kirschner-wire was introduced as a guide from the midpoint on the inferior border of the axis to the superior articular process (SAP) of the atlas, following the preoperative planning for the screw trajectories. The depth to the SAP of the atlas was measured, and a cannulated full-threaded screw of the same length was inserted.
After the ATS was finished, the patient was turned to the prone position. Through a conventional midline posterior approach, iliac bone grafting on the laminae of the atlas and the axis was performed to secure bony fusion. We did not add any other methods to enforce AA stability.
The patient started rehabilitation the next day wearing a soft neck collar, which was continued for 3 months. His symptoms of cervical myelopathy diminished gradually, and he became ambulatory without support (JOA score of 10/17).
Postoperative CT scans obtained just after the surgery showed that the bilateral screws were placed accurately [
Postoperative CT scans obtained the day of the surgery (a-c) and at 6 months postoperatively (d-f). Gaps seen in both lateral atlantoaxial joints (a) and the odontoid process (b) just after the operation were replaced with generated bone at 6 months postoperatively (d, e). Bony fusion was also obtained on the lateral side between the laminae of the atlas and the axis (f), on which autologous bone graft was transplanted (c)
Utility of ATS fixation through conventional Anterior Cervical Approach
ATS fixation has been performed through the anterior retropharyngeal approach.[
Attributes of the cusco speculum for ats exposure
We utilized a Cusco speculum as the wound retractor to perform ATS fixation via the conventional anterior cervical approach. Its shape helps open the deep operative field without soft tissue injury. One recent article reported ATS fixation through a conventional anterior cervical approach,[
Use of full-threaded versus lag screws
We attempted to increase the stability of ATS by modifying the methods for screw fixation, using full-threaded versus lag screws. Full-threaded screws stabilize the axis via the placement of bicortical screws; they therefore provide more rigid/stronger stability. Second, we placed the entry points of the screws at the midpoint on the anterior border of the axis (e.g. versus prior studies using approach 5-10 mm lateral from the midpoint, or at the groove beneath the SAP of the axis[
1. Kansal R, Sharma A, Kukreja S. An anterior high cervical retropharyngeal approach for C1-C2 intrafacetal fusion and transarticular screw insertion. J Clin Neurosci. 2011. 18: 1705-8
2. Koller H, Kammermeier V, Ulbricht D, Assuncao A, Karolus S, van den Berg B. Anterior retropharyngeal fixation C1-2 for stabilization of atlantoaxial instabilities: Study of feasibility, technical description and preliminary results. Eur Spine J. 2006. 15: 1326-38
3. Lesoin F, Autricque A, Franz K, Villette L, Jomin M. Transcervical approach and screw fixation for upper cervical spine pathology. Surg Neurol. 1987. 27: 459-65
4. Li WL, Chi YL, Xu HZ, Wang XY, Lin Y, Huang QS. Percutaneous anterior transarticular screw fixation for atlantoaxial instability: A case series. J Bone Joint Surg Br. 2010. 92: 545-9
5. Vaccaro AR, Lehman AP, Ahlgren BD, Garfin SR. Anterior C1-C2 screw fixation and bony fusion through an anterior retropharyngeal approach. Orthopedics. 1999. 22: 1165-70
6. Wang J, Zhou Y, Zhang Z, Li C, Zheng W, Zhang Y. Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability. Eur Spine J. 2012. 21: 1568-74
7. Zapalowicz K, Radek M. Rheumatoid atlantoaxial instability treated by anterior transarticular C1-C2 fixation. Case report. Neurol Neurochir Pol. 2013. 47: 290-5