The association between atlantoaxial instability and anomalies of vertebral artery and axis

Author(s):  
Chan Woong Byun ◽  
Dong-Ho Lee ◽  
Sehan Park ◽  
Choon Sung Lee ◽  
Chang Ju Hwang ◽  
...  
2018 ◽  
Vol 15 (5) ◽  
pp. E57-E57 ◽  
Author(s):  
Pravin Salunke ◽  
Sushanta K Sahoo

Abstract The pathology in congenital atlantoaxial instability is usually in C1-2 joints. Addressing the joints appears to be the most rationale approach. The joints are usually approached posteriorly, manipulated, and fused. Understanding the normal and abnormal anatomy is important. Normally, the third segment of the vertebral artery courses lateral to the C1-2 joint. However, in about 20% of the cases with complex congenital craniovertberal junction anomalies the artery crosses the joint posteriorly. The artery in such cases may be injured while joint manipulation and instrumentation with disastrous consequences. Alternatively, occipital squama can be fused to the cervical spine. However, this requires fusion of multiple segments affecting the neck movements significantly. An anomalous vertebral artery can be dissected, mobilized, and safeguarded while dissecting, manipulating, and fusing the C1-2 joint. In this operative video, authors have highlighted the technique to safeguard the anomalous vertebral artery during joint manipulation.  Proper informed consent was obtained from the patient.


2019 ◽  
Vol 76 (5) ◽  
pp. 555-558 ◽  
Author(s):  
Drazen Ivetic ◽  
Goran Pavlicevic ◽  
Branislav Antic

Introduction. The atlantoaxial complex is a very complicated structure and open reduction of C1-C2 subluxation is very demanding. Atlantoaxial instability may result from the traumatic, inflammatory, neoplastic, congenital or degenerative disorders. Anatomy of the vertebral artery is essential for surgical approach and sometimes the placement of C2 pedicle screw is not possible. In these instances, the translaminar screw placement in C2 can provide an alternative fixation point in C2, without threatening injury to the vertebral artery. Case report. We presented 54- year-old patient with cervical myelopathy according to traumatic atlantoaxial subluxation. Computed tomography angiography showed a bilateral vertebral artery anomaly of ?high-riding? type. The patient was operated and the posterior C1-C2 screws fixation was used. Due to the vertebral artery anomaly C2 screws were translaminary inserted. Complete reduction of C1-C2 subluxation and excellent neurological improvement were achieved. Conclusion. Surgical treatment of C1-C2 subluxation is very challenging. Many techniques of atlantoaxial fixation have been developed. The use of C2 translaminar screw is an alternative method of fixation in the treatment of atlantoaxial instability, especially in cases with the vertebral artery anomaly.


2017 ◽  
Vol 14 (6) ◽  
pp. 647-653 ◽  
Author(s):  
Alexandra M Giantini Larsen ◽  
Benjamin L Grannan ◽  
Robert M Koffie ◽  
Jean-Valéry Coumans

Abstract BACKGROUND Atlantoaxial instability, which can arise in the setting of trauma, degenerative diseases, and neoplasm, is often managed surgically with C1–C2 arthrodesis. Classical C1–C2 fusion techniques require placement of instrumentation in close proximity to the vertebral artery and C2 nerve root. OBJECTIVE To report a novel C1–C2 fusion technique that utilizes C2 translaminar screws and C1 sublaminar cables to decrease the risk of injury to the vertebral artery and C2 nerve root. METHODS To facilitate fixation to the atlas, while minimizing the risk of injury to the vertebral artery and to the C2 nerve root, we sought to determine the feasibility of using a soft cable around the C1 arch and affixing it to a rod connected to C2 laminar screws. We reviewed our experience in 3 patients. RESULTS We used this technique in patients in whom we anticipated difficult C1 screw placement. Three patients were identified through a review of the senior author's cases. Atlantoaxial instability was associated with trauma in 2 patients and chronic degenerative changes in 1 patient. Common symptoms on presentation included pain and limited range of motion. All patients underwent C1–C2 fusion with C2 translaminar screws with sublaminar cable harnessing of the posterior arch of C1. There were no reports of postoperative complications or hardware failure. CONCLUSION We demonstrate a novel, technically straightforward approach for C1–C2 fusion that minimizes risk to the vertebral artery and to the C2 nerve root, while still allowing for semirigid fixation in instances of both traumatic and chronic degenerative atlantoaxial instability.


2020 ◽  
Vol 3 (1) ◽  
pp. V10
Author(s):  
Sushil Patkar

Fixation for atlantoaxial dislocation is a challenging issue, and posterior C1 lateral mass and C2 pars–pedicle screw plate–rod construct is the standard of care for atlantoaxial instability. However, vertebral artery injury remains a potential complication. Recent literature has focused on intraoperative navigation, the O-arm, 3D printing, and recently use of robots for perfecting the trajectory and screw position to avoid disastrous injury to the vertebral artery and enhance the rigidity of fixation. These technological advances increase the costs of the surgery and are available only in select centers in the developed world.Review of the axis bone anatomy and study of the stress lines caused by weight transmission reveal that the bone below the articular surface of the superior facet is consistently dense as it lies along the line of weight transmission A new trajectory for the axis screw 3–5 mm below the midpoint of the facet joint and directed downward and medially avoids the course of the vertebral artery and holds the axis rigidly. Divergent screw constructs are biomechanically stronger. Variable screw placement (VSP) plates with long shaft screws permit manipulation of the vertebrae and realignment of the facets to the correct reduced position with fixation in the compression mode.The video can be found here: https://youtu.be/E1msiKjM-aA


Author(s):  
Selda Aksoy ◽  
Bulent Yalcin

Abstract Background Atlantoaxial instability is an important disorder that causes serious symptoms such as difficulties in walking, limited neck mobility, sensory deficits, etc. Atlantal lateral mass screw fixation is a surgical technique that has gained important recognition and popularity. Because accurate drilling area for screw placement is of utmost importance for a successful surgery, we aimed to investigate morphometry of especially the posterior part of C1. Methods One hundred and fifty-eight human adult C1 dried vertebrae were obtained. Measurements were performed directly on dry atlas vertebrae, and all parameters were measured by using a digital caliper accurate to 0.01 mm for linear measurements. Results The mean distance between the tip of the posterior arch and the medial inner edge of the groove was found to be 10.59 ± 2.26 and 10.49 ± 2.20 mm on the right and left, respectively. The mean distance between the tip of the posterior arch and the anterolateral outer edge of the groove was 21.27 ± 2.28 mm (right: 20.96 ± 2.22 mm; left: 21.32 ± 2.27 mm). The mean height of the screw entry zone on the right and left sides, respectively, were 3.86 ± 0.81 and 3.84 ± 0.77 mm. The mean width of the screw entry zone on both sides was 13.15 ± 1.17 and 13.25 ± 1.3 mm. Conclusion Our result provided the literature with a detailed database for the morphometry of C1, especially in relation to the vertebral artery groove. We believe that the data in the present study can help surgeons to adopt a more accurate approach in terms of accurate lateral mass screw placement in atlantoaxial instability.


Author(s):  
Tomasz Klepinowski ◽  
Jagoda Cembik ◽  
Leszek Sagan

Abstract Rheumatoid arthritis (RA) might lead to atlantoaxial instability requiring transpedicular or transarticular fusion. High-riding vertebral artery (HRVA) puts patients at risk of injuring the vessel. RA is hypothesized to increase a risk of HRVA. However, to date, no relative risk (RR) has been calculated in order to quantitatively determine a true impact of RA as its risk factor. To the best of our knowledge, this is the first attempt to do so. All major databases were scanned for cohort studies combining words “rheumatoid arthritis” and “high-riding vertebral artery” or synonyms. RA patients were qualified into the exposed group (group A), whereas non-RA subjects into the unexposed group (group B). Risk of bias was explored by means of Newcastle-Ottawa Scale. MOOSE checklist was followed to ensure correct structure. Fixed-effects model (inverse variance) was employed. Four studies with a total of 308 subjects were included in meta-analysis. One hundred twenty-five subjects were in group A; 183 subjects were in group B. Mean age in group A was 62,1 years, whereas in group B 59,9 years. The highest risk of bias regarded “comparability” domain, whereas the lowest pertained to “selection” domain. The mean relative risk of HRVA in group A (RA) as compared with group B (non-RA) was as follows: RR = 2,11 (95% CI 1,47–3,05), I2 = 15,19%, Cochrane Q = 3,54 with overall estimate significance of p < 0,001. Rheumatoid arthritis is associated with over twofold risk of developing HRVA, and therefore, vertebral arteries should be meticulously examined preoperatively before performing craniocervical fusion in every RA patient.


2002 ◽  
Vol 97 (6) ◽  
pp. 1456-1459 ◽  
Author(s):  
Teiji Tominaga ◽  
Toshiyuki Takahashi ◽  
Hiroaki Shimizu ◽  
Takashi Yoshimoto

✓ Vertebral artery (VA) occlusion by rotation of the head is uncommon, but can result from mechanical compression of the artery, trauma, or atlantoaxial instability. Occipital bone anomalies rarely cause rotational VA occlusion, and patients with nontraumatic intermittent occlusion of the VA usually present with compromised vertebrobasilar flow. A 34-year-old man suffered three embolic strokes in the vertebrobasilar system within 2 months. Magnetic resonance imaging demonstrated multiple infarcts in the vertebrobasilar territory. Angiography performed immediately after the third attack displayed an embolus in the right posterior cerebral artery. Radiographic and three-dimensional computerized tomography bone images exhibited an anomalous osseous process of the occipital bone projecting to the posterior arch of the atlas. Dynamic angiography indicated complete occlusion of the left VA between the osseous process and the posterior arch while the patient's head was turned to the right. Surgical decompression of the VA resulted in complete resolution of rotational occlusion of the artery. An occipital bone anomaly can cause rotational VA occlusion at the craniovertebral junction in patients who present with repeated embolic strokes resulting from injury to the arterial wall.


2011 ◽  
Vol 14 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Sun-Ho Lee ◽  
Eun-Sang Kim ◽  
Whan Eoh

The authors report the case of a patient with os odontoideum, myelopathy secondary to atlantoaxial instability, and bilaterally persistent first intersegmental artery at the craniovertebral junction. Instead of occipitocervical fusion, C1–2 posterior fusion was performed using a polyaxial screw/rod system. The information obtained from 3D CT angiography studies may highlight the potential risk of vertebral artery injury in advance and reduce the risk of an intraoperative vertebral artery injury. In addition, C-1 lateral mass screw placement may be a safe procedure for cases of atlantoaxial subluxation in which there are persistent C-1 intersegmental arteries.


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