Subaxial Cervical Pedicular Screw Insertion via the Nonanatomic Axis: Technical Notes and Preliminary Clinical Report

Study Design: Retrospective study. Objective: To report the technical details of subaxial cervical pedicular screw insertion via the nonanatomic axis (nAA-CPS) and evaluate its clinical safety and accuracy. Methods: The nAA-CPS technique was performed in 21 patients. Preoperative and intraoperative management-related details are described, and a manipulation protocol is presented. Clinical outcomes were used to assess the safety and accuracy of screws was evaluated using postoperative computed tomography (CT) according to the pedicle perforation grading system, and the nonanatomic pedicle transverse angle (nPTA) and nonanatomic pedicle axis length (nPAL) were assessed based on pre- and postoperative CT images. Results: According to “one constant entry point (EP) and two perpendicular trajectory angles” protocol, nAA-CPS was performed without much interference from the muscles. No intraoperative or postoperative neurovascular complications related to the technique were observed. Of the 112 inserted screws, 78 (69.64%) were assessed as grade 0, 24 (21.43%) as grade 1, 4 (3.57%) as grade 2 and 6 (5.36%) as grade 3. The overall rate of correct position (grades 0 and 1) was 91.07% (102/112), and the rate of malposition was 8.93% (10/112), including five screws implanted medially and the other five laterally. The nPTA was highly consistent on pre- and postoperative CT (P < .05), while postoperative nPAL was significantly shorter than preoperative nPAL (P > .05). Conclusions: Clinically, the accuracy and safety of nAA-CPS was similar to the traditional CPS technique. The protocol, derived from previous radiological studies and workshops, greatly helped standardize clinical manipulation; thus, nAA-CPS is a promising alternative to the traditional CPS.

[1]  M. Jinzaki,et al.  Usefulness of contrast-enhanced ultrasonography for diagnosis of renal cell carcinoma in dialysis patients , 2019, Medicine.

[2]  Y. Ha,et al.  Accuracy and Safety of Lateral Vertebral Notch-Referred Technique Used in Subaxial Cervical Pedicle Screw Placement. , 2018, Operative neurosurgery.

[3]  T. Sugawara,et al.  Prospective Multicenter Study of a Multistep Screw Insertion Technique Using Patient-Specific Screw Guide Templates for the Cervical and Thoracic Spine , 2018, Spine.

[4]  Zhi Chen,et al.  Preparation and Assessment of an Individualized Navigation Template for Lower Cervical Anterior Transpedicular Screw Insertion Using a Three-Dimensional Printing Technique , 2017, Spine.

[5]  Di Zhang,et al.  Safe placement of lateral mass screw in the subaxial cervical spine: a case series , 2017, International Orthopaedics.

[6]  K. A. Diachkov,et al.  Easy method to simplify “freehand” subaxial cervical pedicle screw insertion , 2017, Journal of craniovertebral junction & spine.

[7]  Sang Ku Jung,et al.  An Assessment of the Medial Angle of Inserted Subaxial Cervical Pedicle Screw during Surgery: Practical Use of Preoperative CT Scanning and Intraoperative X-rays , 2016, Neurologia medico-chirurgica.

[8]  Lihong Cai,et al.  The accuracy and the safety of individualized 3D printing screws insertion templates for cervical screw insertion , 2016, Computer assisted surgery.

[9]  S. Burch,et al.  Safety and Efficacy of Reconstruction of Complex Cervical Spine Pathology Using Pedicle Screws Inserted with Stealth Navigation and 3D Image-Guided (O-Arm) Technology , 2015, Spine.

[10]  Paul W. Millhouse,et al.  Lateral Mass Fixation in the Subaxial Cervical Spine. , 2015, Journal of spinal disorders & techniques.

[11]  K. Suda,et al.  A multicenter study on accuracy and complications of freehand placement of cervical pedicle screws under lateral fluoroscopy in different pathological conditions: CT-based evaluation of more than 1,000 screws , 2014, European Spine Journal.

[12]  S. Jeon,et al.  The Safety and Accuracy of Freehand Pedicle Screw Placement in the Subaxial Cervical Spine: A Series of 45 Consecutive Patients , 2014, Spine.

[13]  J. Dettori,et al.  Lateral mass screw fixation in the cervical spine: a systematic literature review. , 2013, The Journal of bone and joint surgery. American volume.

[14]  Qingsan Zhu,et al.  A Novel Method of Cervical Pedicle Screw Placement From C3 to C5 and Its Clinical Applications , 2013, Spine.

[15]  Sang-Hun Lee,et al.  Cervical Pedicle Screw Placement Using the “Key Slot Technique”: The Feasibility and Learning Curve , 2012, Journal of spinal disorders & techniques.

[16]  Jung-Hee Lee,et al.  Assessment of Pedicle Perforation by the Cervical Pedicle Screw Placement Using Plain Radiographs: A Comparison With Computed Tomography , 2012, Spine.

[17]  S. Komiya,et al.  Cervical pedicle screw insertion using a gutter entry point at the transitional area between the lateral mass and lamina , 2012, European Spine Journal.

[18]  K. Daniel Riew,et al.  Optimal entry points and trajectories for cervical pedicle screw placement into subaxial cervical vertebrae , 2011, European Spine Journal.

[19]  Marco Sassi,et al.  Anatomical considerations for cervical pedicle screw insertion: the use of multiplanar computerized tomography measurements in 122 consecutive clinical cases. , 2009, The spine journal : official journal of the North American Spine Society.

[20]  E. Schneider,et al.  Biomechanical Analysis of Transpedicular Screw Fixation in the Subaxial Cervical Spine , 2004, Spine.

[21]  R. Gaines,et al.  Accuracy of Cervical Pedicle Screw Placement Using the Funnel Technique , 2001, Spine.

[22]  K. Kaneda,et al.  Transpedicular screw fixation for traumatic lesions of the middle and lower cervical spine: description of the techniques and preliminary report. , 1994, Journal of spinal disorders.

[23]  P. Kanna,et al.  Intra-operative computer navigation guided cervical pedicle screw insertion in thirty-three complex cervical spine deformities , 2010, Journal of craniovertebral junction & spine.

[24]  D. Pateder,et al.  Lateral mass screw fixation for cervical spine trauma: associated complications and efficacy in maintaining alignment. , 2006, The spine journal : official journal of the North American Spine Society.