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Minimally invasive percutaneous transpedicular screw fixation: increased accuracy and reduced radiation exposure by means of a novel electromagnetic navigation system.

von Jako R, Finn MA, Yonemura KS, Araghi A, Khoo LT, Carrino JA, Perez-Cruet M - Acta Neurochir (Wien) (2010)

Bottom Line: Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively).Time for insertion did not vary between the two techniques.Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.

View Article: PubMed Central - PubMed

Affiliation: GE Healthcare, Boston, MA, USA. drvonjako@comcast.net

ABSTRACT

Background: Minimally invasive percutaneous pedicle screw instrumentation methods may increase the need for intraoperative fluoroscopy, resulting in excessive radiation exposure for the patient, surgeon, and support staff. Electromagnetic field (EMF)-based navigation may aid more accurate placement of percutaneous pedicle screws while reducing fluoroscopic exposure. We compared the accuracy, time of insertion, and radiation exposure of EMF with traditional fluoroscopic percutaneous pedicle screw placement.

Methods: Minimally invasive pedicle screw placement in T8 to S1 pedicles of eight fresh-frozen human cadaveric torsos was guided with EMF or standard fluoroscopy. Set-up, insertion, and fluoroscopic times and radiation exposure and accuracy (measured with post-procedural computed tomography) were analyzed in each group.

Results: Sixty-two pedicle screws were placed under fluoroscopic guidance and 60 under EMF guidance. Ideal trajectories were achieved more frequently with EMF over all segments (62.7% vs. 40%; p = 0.01). Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively). Fluoroscopy time was reduced 77% with the use of EMF (22 s vs. 5 s per level; p < 0.0001) over all spinal segments. Radiation exposure at the hand and body was reduced 60% (p = 0.058) and 32% (p = 0.073), respectively. Time for insertion did not vary between the two techniques.

Conclusions: Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.

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Related in: MedlinePlus

Drawing showing that an 18-in. field is one of the limiting factors in the use of electromagnetic guidance
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Fig1: Drawing showing that an 18-in. field is one of the limiting factors in the use of electromagnetic guidance

Mentions: Computer-aided fluoroscopic techniques [6, 9, 27, 29, 34] are among the various methodologies devised to increase the accuracy of screw placement; however, widespread adoption has been slow because of the increased set-up and operative times and lack of perceived benefit [3]. Electromagnetic field (EMF) navigation-based systems eliminate cumbersome optical array receivers as well as line-of-sight issues that can interfere with the normal flow of the operative procedure [10, 25]. The trade-off for this flexibility is the limited size of the EMF field (18-in. radial from center of EMF transmitter; Fig. 1). In addition, large ferromagnetic instruments can create distortion within the EMF field. Studies have confirmed that the accuracy of pedicle screw placement is similar using either optical or EMF-based navigation systems [6, 9, 27, 29, 35].Fig. 1


Minimally invasive percutaneous transpedicular screw fixation: increased accuracy and reduced radiation exposure by means of a novel electromagnetic navigation system.

von Jako R, Finn MA, Yonemura KS, Araghi A, Khoo LT, Carrino JA, Perez-Cruet M - Acta Neurochir (Wien) (2010)

Drawing showing that an 18-in. field is one of the limiting factors in the use of electromagnetic guidance
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040822&req=5

Fig1: Drawing showing that an 18-in. field is one of the limiting factors in the use of electromagnetic guidance
Mentions: Computer-aided fluoroscopic techniques [6, 9, 27, 29, 34] are among the various methodologies devised to increase the accuracy of screw placement; however, widespread adoption has been slow because of the increased set-up and operative times and lack of perceived benefit [3]. Electromagnetic field (EMF) navigation-based systems eliminate cumbersome optical array receivers as well as line-of-sight issues that can interfere with the normal flow of the operative procedure [10, 25]. The trade-off for this flexibility is the limited size of the EMF field (18-in. radial from center of EMF transmitter; Fig. 1). In addition, large ferromagnetic instruments can create distortion within the EMF field. Studies have confirmed that the accuracy of pedicle screw placement is similar using either optical or EMF-based navigation systems [6, 9, 27, 29, 35].Fig. 1

Bottom Line: Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively).Time for insertion did not vary between the two techniques.Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.

View Article: PubMed Central - PubMed

Affiliation: GE Healthcare, Boston, MA, USA. drvonjako@comcast.net

ABSTRACT

Background: Minimally invasive percutaneous pedicle screw instrumentation methods may increase the need for intraoperative fluoroscopy, resulting in excessive radiation exposure for the patient, surgeon, and support staff. Electromagnetic field (EMF)-based navigation may aid more accurate placement of percutaneous pedicle screws while reducing fluoroscopic exposure. We compared the accuracy, time of insertion, and radiation exposure of EMF with traditional fluoroscopic percutaneous pedicle screw placement.

Methods: Minimally invasive pedicle screw placement in T8 to S1 pedicles of eight fresh-frozen human cadaveric torsos was guided with EMF or standard fluoroscopy. Set-up, insertion, and fluoroscopic times and radiation exposure and accuracy (measured with post-procedural computed tomography) were analyzed in each group.

Results: Sixty-two pedicle screws were placed under fluoroscopic guidance and 60 under EMF guidance. Ideal trajectories were achieved more frequently with EMF over all segments (62.7% vs. 40%; p = 0.01). Greatest EMF accuracy was achieved in the lumbar spine, with significant improvements in both ideal trajectory and reduction of pedicle breaches over fluoroscopically guided placement (64.9% vs. 40%, p = 0.03, and 16.2% vs. 42.5%, p = 0.01, respectively). Fluoroscopy time was reduced 77% with the use of EMF (22 s vs. 5 s per level; p < 0.0001) over all spinal segments. Radiation exposure at the hand and body was reduced 60% (p = 0.058) and 32% (p = 0.073), respectively. Time for insertion did not vary between the two techniques.

Conclusions: Minimally invasive pedicle screw placement with the aid of EMF image guidance reduces fluoroscopy time and increases placement accuracy when compared with traditional fluoroscopic guidance while adding no additional time to the procedure.

Show MeSH
Related in: MedlinePlus