An anatomical study comparing standard fluoroscopy and virtual fluoroscopy for the placement of C1–2 transarticular screws

Abstract

<jats:p content-type="fine-print"><jats:italic>Object.</jats:italic> The authors sought to compare radiation exposure, surgical time, and accuracy of screw placement when using either standard fluoroscopy or virtual fluoroscopy for the placement of C1–2 transarticular screws.</jats:p> <jats:p content-type="fine-print"><jats:italic>Methods.</jats:italic> Twenty-two C1–2 transarticular screws were placed in 11 cadavers in a randomized and alternating order by using either standard fluoroscopy or virtual fluoroscopy (fluoronavigation). The radiation time, procedure time, and accuracy of screw placement were recorded and statistically compared. A small but statistically significant reduction in fluoroscopy time was noted with the virtual fluoroscopy technique but the surgical times were similar between the two techniques. The incidence of noncritical and critical breaches (those at risk of causing a neurovascular injury) was not significantly different between the two groups. Careful analysis of the C1–2 anatomy in these specimens underscored the importance of placing the screw path in a maximally dorsal and medial portion of the C-2 isthmus to avoid injury to the vertebral artery and to maximize the bone purchase of the C-1 lateral mass.</jats:p> <jats:p content-type="fine-print"><jats:italic>Conclusions.</jats:italic> Although virtual fluoroscopy may represent a useful tool for transarticular screw placement, it does not supplant traditional surgical techniques and does not appear to lower the incidence of bone breaches that can occur when performing this demanding procedure.</jats:p>

Radiation Exposure During Pedicle Screw Placement in Adolescent Idiopathic Scoliosis: Is Fluoroscopy Safe?

“…Newly emerging methods such as image-guided virtual fluoroscopy should certainly be evaluated, because they have been shown to reduce fluoroscopy time by approximately 40% while maintaining accuracy. 12 Radiation-reducing gloves like those worn in this study should be utilized in order to minimize exposure to the hands, especially considering that Mehlman et al saw dosage levels at the hands approaching 40 mSv per minute of direct beam exposure. 13 Further investigation into the quantity and safety of hand irradiation during pediatric spinal procedures is hoped.…”

“…Except for the Hafez study, 6 all papers encountered in the literature have concerned fluoroscopically-guided procedures done on anthropomorphic phantoms, 3,4,11 vertebral models, 7 or cadaveric specimens. 8,9,12 The direct comparability of results in simulated trials to those from human trials is not clear. Additionally, those studies that concerned pedicle screw insertion concentrated solely on the lumbar spine, 3,8,11 which contains the largest and therefore easiest pedicles to instrument.…”

“…They found that, although accuracy does not significantly vary, image-guided systems decrease fluoroscopy time nearly 40%. 9,12 Unfortunately, this technology is still experimental and realistically years away from widespread use. 9,12 Therefore, for the time being, it must be ascertained whether the prevalent C-arm fluoroscopy method is of significant risk, and, if so, what may be done now to reduce the risk until better methods are available.…”

“…[3][4][5][6][7][8][9][10][11][12][13] While the majority of current research into the safety of fluoroscopy has involved cardiac catheterization procedures, various papers have also addressed the safety of fluoroscopically-guided spinal surgery. 3,4,[7][8][9]11,12 Jones et al 3 found the radiation exposure to the physician during lumbar pedicle screw insertion to be measurable yet still less than 10% of recommended limits for the hand, thyroid, and eyes. 3 It should be noted that their procedures were completed on anthropomorphic phantoms and few screws were placed in each patient, so the radiation exposure during in vivo pedicle screw insertion procedures may actually vary.…”

Anterior retropharyngeal fixation C1-2 for stabilization of atlantoaxial instabilities: study of feasibility, technical description and preliminary results

“…Breaching of the C1-2 joints is also known in PTS [51]. Although it was not symptomatic in any of our cases, it should be avoided and the screw length inside the lateral mass C1 should respect its medial height.…”