Biomechanical Comparison of C1-C2 Posterior Fixations

Naderi, Sait; Crawford, Neil R.; Song, Geun Sung; Sonntag, Volker K. H.; Dickman, Curtis A.

doi:10.1097/00007632-199809150-00005

Cited by 199 publications

(104 citation statements)

References 18 publications

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“…Atlantoaxial transarticular screw fixation, first introduced by Magerl and Seemann [13], has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation [7,16]. However, this operation has its own risks, notably one of which is an intraoperative injury to the vertebral artery [17,18].…”

Section: Introductionmentioning

confidence: 99%

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

et al. 2009

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The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1-C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and nonrheumatoid patients. Contributing radiological factors to the subluxation have also not been evaluated. The objective of this study was to evaluate subaxial subluxation after atlantoaxial transarticular screw fixation in patients with and without RA and to find contributing factors. Fortythree patients who submitted to atlantoaxial transarticular screw fixation without any concomitant operation were followed up for more than 1 year. Subaxial subluxation and related radiological factors were evaluated by functional X-ray measurements. Statistical analyses showed that aggravations of subluxation of 2.5 mm or greater were more likely to occur in RA patients than in non-RA patients over an average of 4.2 years of follow-up, and postoperative subluxation occurred in the anterior direction in the upper cervical spine. X-ray evaluations revealed that such patients had a significantly smaller postoperative C2-C7 angle, and that the postoperative AA angle correlated negatively with this. Furthermore, anterior subluxation aggravation was significantly correlated with the perioperative atlantoaxial and C2-C7 angle changes, and these two changes were strongly correlated to each other. In conclusion, after atlantoaxial transarticular screw fixation, rheumatoid patients have a greater risk of developing subaxial subluxations. The increase of the atlantoaxial angel at the operation can lead to a decrease in the C2-C7 angle, followed by anterior subluxation of the upper cervical spine and possibly neurological deterioration.

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Section: Introductionmentioning

confidence: 99%

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

et al. 2009

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“…Fundamentally, these indications are related to chronic and acute atlanto-axial instability. Transarticular screw arthrodesis provides immediate rigid atlanto-axial fixation and it has biomechanical advantages when compared to other techniques [7,9,17,22]. Transarticular C1-C2 screw fixation could be performed even with fracture, destruction or absence of the posterior arch of the atlas.…”

Section: Introductionmentioning

confidence: 99%

Multiplanar reconstructions of helical computed tomography in planning of atlanto-axial transarticular fixation

Nogueira-Barbosa

Defino

2005

Eur Spine J

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The objective of this study was to determine atlanto-axial bone morphometric measurements related to screw transarticular fixation technique. One hundred helical computerized tomography (helical CT) scans with volumetric acquisition, including the first and the second cervical vertebrae, were studied. The screw insertion axis according to the Magerl technique for C1-C2 transarticular fixation was the referential to select the correct oblique axial and oblique parasagittal planes obtained with multiplanar reconstruction (MPR) on helical CT. The selected measured parameters on each side of the vertebrae were C2 interarticular isthmus height and width, optimal screw length, optimal screw trajectory sagittal and axial angles, and the distance between the ideal screw trajectory and the vertebral artery groove. C2 interarticular isthmus height measured 7.75±1.27 mm, C2 interarticular isthmus width 7.94±1.72 mm, optimal screw length 39.03±2.81 mm, optimal screw trajectory sagittal angle 57.54±5.28°, optimal screw trajectory medial angle 7.90±4.05°. Isthmus narrowing under 5 mm (height and/or width) was seen in 5% of cases. In 30% of cases reconstructed parasagittal images showed the vertebral artery groove.In those cases, the distance between the vertebral artery groove and the ideal screw path was measured. This distance measured under 2.5 mm in 7% of C2 articular masses. A classification of C2 articular mass morfology was proposed. The C2 articular masses without anatomic variations predisposing to vertebral artery injury were considered type I. The C2 articular masses potentially associated with vascular injury (12%) were classified as type II. Potential risk was identified at the C2 isthmus only (3%), at the anterior portion of C2 articular mass only (7%) or at both regions (2%). According to selected criteria 18% of patients would have at least one side C2 articular mass with potential risk for the vertebral artery. In 6% of patients the potential risk was identified bilaterally. There is a great variation in the maximum and minimum values of the anatomic measurements. Therefore preoperative CT scans are very important to identify type II cases, such that the surgeon may preoperatively define the bony anatomy trough which the screws will pass.

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“…But these patients still achieved biomechanics stability of C1-2 as a result of bilateral transarticular screw fixation. Normally, the superiority of the biomechanics of surgical stability of the C1-C2 articulation had been found in three point fixations (two transarticular screw plus posterior fixation) [20,21]. This may be explained by the enhancement stability of unilateral screw fixation derived from tighten C1 arch and C2 spinous process with [22].…”

Section: Discussionmentioning

confidence: 99%

Atlantoaxial transarticular screw fixation and posterior fusion using polyester cable: a 10-year experience

Sutipornpalangkul

Thanapipatsiri

2013

Eur Spine J

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Purpose To retrospective review the clinical outcomes of the modified operative technique using a polyester suture material (Ethibond* Excel) for atlantoaxial transarticular screw fixation and posterior fusion. Methods The retrospective reviews were conducted from 2002 to 2012. The patient's medical record reviews included demographic data, cause of atlantoaxial instability, orthopedic and surgical history, clinical presentation, radiographic finding including plain radiography, complications, operative detail, and outcome of treatment. Fusion of C1-C2 was defined as either graft consolidation or absence of C1-C2 movement on lateral flexion-extension radiograph.Results Twenty-three patients demonstrated clinical and radiographic evidence of atlantoaxial instability (13 men and 10 women, with a mean age of 42 years). Majority of atlantoaxial instability was caused by trauma. Most common clinical symptom was neck pain with or without cervical myelopathy. Bilateral screws were placed in 18 of the 23 patients. Five patients underwent placement of unilateral screws. The 13 patients were inserted by screws with diameter 4.0 mm. The means screw length was 40.33 mm. The means of operative time and estimated blood loss were 3.6 h and 234 ml, respectively. The mean of follow-up duration was 18 months. All 41 screws were positioned satisfactorily in C1 lateral mass. All 23 patients achieved fusion (100 % fusion rate). After a period of follow-up, 9 of the 10 neurological deficit patients had completely recovered. Conclusions We concluded that the atlantoaxial transarticular screw fixation and posterior fusion using polyester cable can be used for C1-2 fusion with a high fusion rate and less complications in various cases.

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Biomechanical Comparison of C1-C2 Posterior Fixations

Abstract: It is mechanically advantageous to include as many fixation points as possible when atlantoaxial instability is treated surgically.

Cited by 199 publications

References 18 publications

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients

Multiplanar reconstructions of helical computed tomography in planning of atlanto-axial transarticular fixation

Atlantoaxial transarticular screw fixation and posterior fusion using polyester cable: a 10-year experience

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