Minimally invasive cervical pedicle screw fixation via the posterolateral approach for metastatic cervical spinal tumors

Abstract

Abstract:Background: To avoid lateral misplacement of midcervical pedicle screws, we developed a method for Minimally Invasive Cervical Pedicle Screw (MICEPS) fixation via a posterolateral approach. This intramuscular approach allows for horizontal pedicle screw insertion and reduced intraoperative bleeding. We reviewed our initial experience with MICEPS fixation for patients with cervical metastases.Methods: This study included 18 consecutive patients who received cervical spinal surgery for metastatic tumor. We treated 12 patients with conventional cervical pedicle screw fixation, and 6 patients with the MICEPS fixation technique. Average follow-up was 14 months (range 3 to 34). We inserted 117 pedicle screws using the navigation system. Average fusion area was 4.9 vertebrae (range 3 to 8). Alpha-angles between a line perpendicular to the posterior cortex of the vertebral body and the screw trajectory in the transverse plane were also measured.Results: The average surgical time was 250 min (range 151 to 420 min) with the conventional pedicle screw fixation and 234 min (range 154 to 300 min) with the MICEPS fixation. The average total blood loss was 780 mL (range, 180-1430 mL) in the conventional pedicle screw fixation group and 180 mL (range, 70-400 mL) in the MICEPS fixation group. At the level of midcervical (C3-5), average alpha-angles was 52 degrees (range 43 to 62) in MICEPS fixation group, and 39 degrees (range 19 to 55) in conventional cervical pedicle screw group.Conclusions: The MICEPS fixation technique uses an intramuscular approach, which is minimally invasive and reduces intraoperative bleeding. Intramuscular approach allows for horizontal pedicle screw insertion, and reduced critical screw deviation.

Accurate and Minimally Invasive Cervical Pedicle Screw Insertion Procedure Using the Bone Biopsy Needle as Drill Guide

“…The CPS fixation technique was first described by Abumi 1) . Despite its mechanical advantages, it was associated with potential risk of iatrogenic damage to neurovascular structures because of the small size and steep oblique axis of the cervical pedicles [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] . The mispositioning rate of CPSs inserted by a free-hand technique was reported in the range of 6.7% to 29% 1,4,11) .…”

“…2) For anterior fixation, a skin incision of approximately 5 cm was made, and cervical vertebral bodies were exposed using Southwick's method. For posterior fixation, bilateral skin incisions of approximately 4 cm were made, and then the edge of the lateral mass was exposed using Tokioka's method 13,14,16) . A separate midline posterior approach was implemented when posterior decompression was necessary.…”

“…Favorable clinical results for CPS fixation have been reported for cervical trauma cases [1][2][3] . However, it needs wide soft tissue detachment to expose the entry point and carries the potential risk of vertebral artery (VA), nerve root, and spinal cord injury [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] . To avoid CPS mispositioning, several technical innovations such as the image-guided technique 2,3) , surgical navigation system 5,8,13,14,16) , computed tomography (CT) cutout technique 7) , mechanical aiming device 6) , and screw guide template system 10,12) have been introduced.…”

A Review of the Historical Evolution, Biomechanical Advantage, Clinical Applications, and Safe Insertion Techniques of Cervical Pedicle Screw Fixation

“…When the bone is severely fragile, CPS is the preferred option for posterior stabilization 34) . In metastatic tumors, where the anterior body is destroyed, CPS stabilization offers a palliative management 35,36) .…”

“…Neither of the misplaced screws was laterally deviated in the minimally invasive group. Sugimoto et al 36) compared conventional technique with minimally invasive technique of CPS in midcervical spine for stabilizing metastatic cervical spinal tumors. The minimally invasive technique was beneficial with less blood loss (average of 750 mL in the conventional method and 180 mL in the minimally invasive technique), more horizontal insertion (average of 52°in the minimally invasive technique and 39°in the conventional technique) of the screws, and reduced screw deviation.…”