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Minimally invasive pedicle screw fixation utilizing O-arm fluoroscopy with computer-assisted navigation: Feasibility, technique, and preliminary results.

Park P, Foley KT, Cowan JA, Marca FL - Surg Neurol Int (2010)

Bottom Line: We present our technique and review the results from a cohort of patients who underwent minimally invasive lumbar pedicle screw placement utilizing the O-arm imaging unit in conjunction with the StealthStation Treon System.All breaches were graded as 0-2 mm and were asymptomatic.In the remaining three patients, post-instrumentation O-arm imaging did not demonstrate pedicle screw misplacement.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurosurgery, University of Michigan Health System, Ann Arbor, MI, USA.

ABSTRACT

Background: Pedicle screw misplacement is relatively common, with reported rates ranging up to 42%. Although computer-assisted image guidance (CaIG) has been shown to improve accuracy in open spinal surgery, its use in minimally invasive procedures has not been as well evaluated. We present our technique and review the results from a cohort of patients who underwent minimally invasive lumbar pedicle screw placement utilizing the O-arm imaging unit in conjunction with the StealthStation Treon System.

Methods: A retrospective review of patients who underwent minimally invasive pedicle screw fixation with CaIG was performed. Eleven consecutive patients were identified and all were included. Nine patients underwent a single-level transforaminal lumbar interbody fusion. Two patients underwent multi-level fusion. Inaccurate pedicle screw placement was determined by postoperative computed tomography (CT) and graded as 0-2, 2-4, 4-6, or 6-8 mm.

Results: A total of 52 screws were placed. Forty screws were inserted in eight patients who had postoperative CT, and a misplacement rate of 7.5% was noted including one lateral and two medial breaches. All breaches were graded as 0-2 mm and were asymptomatic. In the remaining three patients, post-instrumentation O-arm imaging did not demonstrate pedicle screw misplacement.

Conclusion: Although this initial study evaluates a relatively small number of patients, minimally invasive pedicle screw fixation utilizing the O-arm and StealthStation for CaIG appears to be safe and accurate.

No MeSH data available.


Diagram showing the technique for K-wire insertion through pedicle, using LDG with reference arc positioned toward the StealthStation camera at the foot of the operating room table
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Figure 0002: Diagram showing the technique for K-wire insertion through pedicle, using LDG with reference arc positioned toward the StealthStation camera at the foot of the operating room table

Mentions: With the O-arm moved to the patient’s head, two paramedian 1-inch incisions overlying the target spinal segment were then made. The Stealth long drill guide (LDG) was then inserted through the fascia and used to locate the proper starting site and trajectory for pedicle screw placement. Positioning of the LDG was entirely based on image guidance without visualization of the spinal anatomy [Figures 2 and 3]. After appropriate positioning, a K-wire was placed through the LDG and driven into the pedicle to an approximate depth of 3 cm. This process was repeated for the remaining pedicles. A/P and lateral fluoroscopic views were obtained after placement of all the K-wires to confirm adequate placement. The K-wires were then gently splayed to either side and anchored with a snap. From the most symptomatic side, a tubular retractor was then inserted over the target disk space, using one of the existing incisions. This was followed by TLIF, performed in a manner similar to that described by Holly et al.[4] After the TLIF, a pedicle screw connected to a screw extender was inserted over each K-wire into the pedicle. The screw extenders were then used to align the screw heads so that a rod could be placed. After placement of the set screws, the screw extenders were removed.


Minimally invasive pedicle screw fixation utilizing O-arm fluoroscopy with computer-assisted navigation: Feasibility, technique, and preliminary results.

Park P, Foley KT, Cowan JA, Marca FL - Surg Neurol Int (2010)

Diagram showing the technique for K-wire insertion through pedicle, using LDG with reference arc positioned toward the StealthStation camera at the foot of the operating room table
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2958329&req=5

Figure 0002: Diagram showing the technique for K-wire insertion through pedicle, using LDG with reference arc positioned toward the StealthStation camera at the foot of the operating room table
Mentions: With the O-arm moved to the patient’s head, two paramedian 1-inch incisions overlying the target spinal segment were then made. The Stealth long drill guide (LDG) was then inserted through the fascia and used to locate the proper starting site and trajectory for pedicle screw placement. Positioning of the LDG was entirely based on image guidance without visualization of the spinal anatomy [Figures 2 and 3]. After appropriate positioning, a K-wire was placed through the LDG and driven into the pedicle to an approximate depth of 3 cm. This process was repeated for the remaining pedicles. A/P and lateral fluoroscopic views were obtained after placement of all the K-wires to confirm adequate placement. The K-wires were then gently splayed to either side and anchored with a snap. From the most symptomatic side, a tubular retractor was then inserted over the target disk space, using one of the existing incisions. This was followed by TLIF, performed in a manner similar to that described by Holly et al.[4] After the TLIF, a pedicle screw connected to a screw extender was inserted over each K-wire into the pedicle. The screw extenders were then used to align the screw heads so that a rod could be placed. After placement of the set screws, the screw extenders were removed.

Bottom Line: We present our technique and review the results from a cohort of patients who underwent minimally invasive lumbar pedicle screw placement utilizing the O-arm imaging unit in conjunction with the StealthStation Treon System.All breaches were graded as 0-2 mm and were asymptomatic.In the remaining three patients, post-instrumentation O-arm imaging did not demonstrate pedicle screw misplacement.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neurosurgery, University of Michigan Health System, Ann Arbor, MI, USA.

ABSTRACT

Background: Pedicle screw misplacement is relatively common, with reported rates ranging up to 42%. Although computer-assisted image guidance (CaIG) has been shown to improve accuracy in open spinal surgery, its use in minimally invasive procedures has not been as well evaluated. We present our technique and review the results from a cohort of patients who underwent minimally invasive lumbar pedicle screw placement utilizing the O-arm imaging unit in conjunction with the StealthStation Treon System.

Methods: A retrospective review of patients who underwent minimally invasive pedicle screw fixation with CaIG was performed. Eleven consecutive patients were identified and all were included. Nine patients underwent a single-level transforaminal lumbar interbody fusion. Two patients underwent multi-level fusion. Inaccurate pedicle screw placement was determined by postoperative computed tomography (CT) and graded as 0-2, 2-4, 4-6, or 6-8 mm.

Results: A total of 52 screws were placed. Forty screws were inserted in eight patients who had postoperative CT, and a misplacement rate of 7.5% was noted including one lateral and two medial breaches. All breaches were graded as 0-2 mm and were asymptomatic. In the remaining three patients, post-instrumentation O-arm imaging did not demonstrate pedicle screw misplacement.

Conclusion: Although this initial study evaluates a relatively small number of patients, minimally invasive pedicle screw fixation utilizing the O-arm and StealthStation for CaIG appears to be safe and accurate.

No MeSH data available.