Technical errors in pedicle screw placement in computer assisted minimally invasive spine surgery : = Technische Fehler bei der Platzierung von Pedikelschrauben in der minimalinvasiven computerunterstützten Wirbelsäulenchirurgie

Abstract: Background: The placement of pedicle screws (PS) has become a cornerstone in spinal
surgery and computer assisted navigation (CAN) reduces PS misplacements. Most previous
attempts on evaluating the technical accuracy by measuring deviations from the virtual and the
real PS screws have been based on a preoperative computer tomography (CT) scan, both in
fluoroscopy guided and in robotic navigation guided. As such, these studies did not address the
fundamental question of the technical accuracy of the navigation device itself after
intraoperative placement of the virtual PS or of intraoperative risk factors. Other studies that
assessed the technical accuracy from intraoperative placed virtual screws were instead limited
in size, generalizability, and without an analysis of possible risk factors. Therefore, we aim to
investigate the technical errors of intraoperative CAN in the placement of PS in MISS and
explore the associated risk factors for PS mispositioning. Methods: In this retrospective study,
175 patients ≥18 years old (operated 2015-2021) with PS fixation were included. Intraoperative
3D scans were fused with the first postoperative CT scan. Primary endpoint was measured as
angular deviation (PAD) in degrees and lateral deviation (APD) in mm between the planned
and actual PS position and was defined as the technical errors. Established deviation criteria
(according to Gertzbein) were correlated. Age, gender, body mass index (BMI), back tissue
depth (BTD), PS loosening, surgical time (ST), estimated blood loss (EBL), PS size and type
of navigation device were considered as possible outcome affecting variables. Statistical
analyses were performed using Mann-Whitney and Kruskal-Wallis tests. A multivariate
generalized linear model (GLM) analyzed the impact on the primary endpoint. Results: 952
PS were measured. The mean PAD was 5.32±3.70° and the mean APD was 2.97±1.83 mm. A
larger PAD was associated with the use of the Spine Tracker compared to SpineMask®. More
EBL and higher BMI were associated with greater APD. A larger PAD and APD were
associated with longer ST. Higher PAD and APD were associated with PS loosening. PS length
and male patients predicted better PAD, Spine Tracker predicted worse PAD, and longer ST
predicted worse PAD and APD. Conclusion: The technical error was 5.32° (PAD) and 2.97
mm (APD). PS dimensions, ST, EBL, BMI, navigation type, and gender category were
associated with more PS deviations. Nevertheless, both clamp and adhesive fixed reference
frames can be considered clinically accurate, but surgeons should be mindful of possible risk
factors for technical inaccuracies. We encourage further studies to assess possible outcome
affecting variables on PS placements

Object Details

• Alternative title: Technische Fehler bei der Platzierung von Pedikelschrauben in der minimalinvasiven computerunterstützten Wirbelsäulenchirurgie
• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Notes: Universität Freiburg, Dissertation, 2024

Classification and Topics

• Keyword: Minimal-invasive Chirurgie ; Wirbelsäulenchirurgie

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2024
• Creator: Doria-Medina, Roberto
• Contributor: Hubbe, Ulrich ; Meiß, Frank ; Klinik für Neurochirurgie. Freiburg im Breisgau ; Albert-Ludwigs-Universität Freiburg. Medizinische Fakultät

Further information

• DOI: 10.6094/UNIFR/246318
• URN: urn:nbn:de:bsz:25-freidok-2463183
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 06.04.2025, 1:41 AM CEST