Accuracy of fluoroscopic guidance with the coaxial view of the pedicle for percutaneous insertion of lumbar pedicle screws and risk factors for pedicle breach

Abstract

OBJECTIVEIn this study the authors aimed to evaluate the rate of malposition, including pedicle breach and superior facet violation, after percutaneous insertion of pedicle screws using the coaxial fluoroscopic view of the pedicle, and to assess the risk factors for pedicle breach.METHODSIn total, 394 percutaneous screws placed in 85 patients using the coaxial fluoroscopic view of the pedicle between January 2014 and September 2017 were assessed, and 445 pedicle screws inserted in 116 patients using conventional open procedures were used for reference. Pedicle breach and superior facet violation were evaluated by postoperative 0.4-mm slice CT.RESULTSSuperior facet violation was observed in 0.5% of the percutaneous screws and 1.8% of the conventionally inserted screws. Pedicle breach occurred more frequently with percutaneous screws (28.9%) than with conventionally inserted screws (11.9%). The breaches in percutaneous screws were minor and did not reduce the interbody fusion rate. The angle difference between the percutaneous and conventionally inserted screws was comparable. Insertion at the L3 or L4 level, right-sided insertion, placement around a trefoil canal, smaller pedicle angle, and a small difference between the screw and pedicle diameters were found to be risk factors for pedicle breach by percutaneous pedicle screws.CONCLUSIONSPercutaneous pedicle screw placement using the coaxial fluoroscopic view of the pedicle carries a low risk of superior facet violation. The screws should be placed carefully considering the level and side of insertion, canal shape, and pedicle angle.

Letter to the Editor on “Transpedicular Screw Placement Accuracy Using the O-Arm Versus Freehand Technique at a Single Institution. Global Spine Journal” by Crawford et al

“…Previous studies have noted that such “trefoil” shaped spinal canals portend a higher risk of medial pedicle wall perforations during screw placement following the conventional insertion landmarks and trajectory—this can also be avoided by the use of navigation. 6 , 7 We compliment the authors for choosing to study an important topic in modern-day spine surgery, and hope that our observations provide the readers with an additional perspective with which they may interpret this study’s findings.…”

The role of counter-torque holders in tightening of pedicle screw-rod constructs: a biomechanical study in a porcine model

“…Screw-rod construct failures resulting from inappropriate rod bending, incorrect application of rods over screw tulips, set screw breakage, screw/rod dislodgement, progressive kyphosis, disengaged screw tulips, and inappropriate tulip-set screw tightening techniques have also been reported [14], [18]. Even if proper pedicle screw insertion is confirmed by perioperative fluoroscopy, the postoperative pedicle wall breach can reach 11.9% to 28.9% after final rod-screw assembly [19].…”

Reoperation for Misplaced Pedicle Screws: A Multicenter Retrospective Study

“…Use of various insertion techniques other than the freehand insertion technique has been expected to decrease the risk of misplacements, but not abolish it completely. [13][14][15][16] Moreover, the justification for increased accuracy at the expense of increased cost and radiation exposure remains debatable. Therefore, we believe there remains many opportunities to insert pedicle screws using conventional freehand technique because of the simplicity and cost effectiveness.…”