Minimally invasive percutaneous transpedicular screw fixation: increased accuracy and reduced radiation exposure by means of a novel electromagnetic navigation system

OBJECTIVENavigation-enabling technology such as 3D-platform (O-arm) or intraoperative mobile CT (iCT-Airo) systems for use in spinal surgery has considerably improved accuracy over that of traditional fluoroscopy-guided techniques during pedicular screw positioning. In this study, the authors compared 2 intraoperative imaging systems with navigation, available in their neurosurgical unit, in terms of the accuracy they provided for transpedicular screw fixation in the thoracic and lumbar spine.METHODSThe authors performed a retrospective analysis of clinical and surgical data of 263 consecutive patients who underwent thoracic and lumbar spine screw placement in the same center. Data on 97 patients who underwent surgery with iCT-Airo navigation (iCT-Airo group) and 166 with O-arm navigation (O-arm group) were analyzed. Most patients underwent surgery for a degenerative or traumatic condition that involved thoracic and lumbar pedicle screw fixation using an open or percutaneous technique. The primary endpoint was the proportion of patients with at least 1 screw not correctly positioned according to the last intraoperative image. Secondary endpoints were the proportion of screws that were repositioned during surgery, the proportion of patients with a postoperative complication related to screw malposition, surgical time, and radiation exposure. A blinded radiologist graded screw positions in the last intraoperative image according to the Heary classification (grade 1–3 screws were considered correctly placed).RESULTSA total of 1361 screws placed in 97 patients in the iCT-Airo group (503 screws) and in 166 in the O-arm group (858 screws) were graded. Of those screws, 3 (0.6%) in the iCT-Airo group and 4 (0.5%) in the O-arm group were misplaced. No statistically significant difference in final accuracy between these 2 groups or in the subpopulation of patients who underwent percutaneous surgery was found. Three patients in the iCT-Airo group (3.1%, 95% CI 0%–6.9%) and 3 in the O-arm group (1.8%, 95% CI 0%–4.0%) had a misplaced screw (Heary grade 4 or 5). Seven (1.4%) screws in the iCT-Airo group and 37 (4.3%) in the O-arm group were repositioned intraoperatively (p = 0.003). One patient in the iCT-Airo group and 2 in the O-arm group experienced postoperative neurological deficits related to hardware malposition. The mean surgical times in both groups were similar (276 [iCT-Airo] and 279 [O-arm] minutes). The mean exposure to radiation in the iCT-Airo group was significantly lower than that in the O-arm group (15.82 vs 19.12 mSv, respectively; p = 0.02).CONCLUSIONSIntroduction of a mobile CT scanner reduced the rate of screw repositioning, which enhanced patient safety and diminished radiation exposure for patients, but it did not improve overall accuracy compared to that of a mobile 3D platform.

Download Full-text

Hidden blood loss and its influencing factors after minimally invasive percutaneous transpedicular screw fixation in thoracolumbar fracture

10.21203/rs.3.rs-445719/v1 ◽

2021 ◽

Author(s):

Xin Yue ◽

Kaige Mao ◽

Ming Yang ◽

Wentao Zhang ◽

Zhonghai Li

Keyword(s):

Blood Loss ◽

Minimally Invasive ◽

Screw Fixation ◽

Linear Regression Analysis ◽

Thoracolumbar Fracture ◽

Multivariate Linear Regression Analysis ◽

Vertebral Height ◽

Hidden Blood Loss ◽

Transpedicular Screw ◽

Transpedicular Screw Fixation

Abstract Objective: This study aimed to investigate the amount of hidden blood loss (HBL) and its influencing factors after minimally invasive percutaneous transpedicular screw fixation (MIPTSF) in thoracolumbar fracture.Summary of Background Data: MIPTSF is generally accepted as a minimally invasive treatment for thoracolumbar fracture. However, HBL caused by this procedure is usually disregarded.Materials and Methods: Between October 2017 and December 2020, a total of 146 patients (106 males and 40 females, age range 21–59 years) were retrospectively examined, and their clinical and radiological data were recorded and analyzed. The Pearson or Spearman correlation analysis was used to investigate an association between patient’s characteristics and HBL. Multivariate linear regression analysis was performed to elucidate the related clinical or radiological factors of HBL.Results: A substantial amount of HBL (164.00 ±112.02 ml, 40.65% of TBL) occurred after transpedicular screw internal fixation. Multivariate linear regression analysis revealed that HBL was positively associated with total blood loss (TBL) (P=.000), percentage of vertebral height loss (VHL) (P=.000), percentage of vertebral height restoration (VHR) (P=.000), numbers of fractured vertebrae (P=.013), and numbers of fixed vertebral segments (P=.002).Conclusion: A large amount of HBL was incurred in patients undergoing MIPTSF in thoracolumbar fracture. More importantly, TBL, percentage of VHL, percentage of VHR, the numbers of fractured vertebrae and fixed vertebral segments were independent risk factors for HBL.

Download Full-text

Electromagnetic Navigation System-Guided Microwave Ablation of Hepatic Tumors: A Matched Cohort Study

CardioVascular and Interventional Radiology ◽

10.1007/s00270-020-02761-6 ◽

2021 ◽

Author(s):

K. I. Ringe ◽

G. H. Pöhler ◽

H. Rabeh ◽

F. Wacker

Keyword(s):

Cohort Study ◽

Navigation System ◽

Microwave Ablation ◽

Matched Cohort ◽

Hepatic Tumors ◽

Electromagnetic Navigation ◽

Matched Cohort Study ◽

Electromagnetic Navigation System

Download Full-text

Automatic Registration for Navigation at the Anterior and Lateral Skull Base

Annals of Otology Rhinology & Laryngology ◽

10.1177/0003489419849086 ◽

2019 ◽

Vol 128 (10) ◽

pp. 894-902 ◽

Cited By ~ 2

Author(s):

Julia Kristin ◽

Manuel Burggraf ◽

Dirk Mucha ◽

Christoph Malolepszy ◽

Silvan Anderssohn ◽

...

Keyword(s):

Skull Base ◽

Navigation System ◽

Automatic Registration ◽

Total N ◽

Electromagnetic Navigation ◽

Registration Error ◽

Target Registration Error ◽

Lateral Skull Base ◽

Significant Difference ◽

Electromagnetic Navigation System

Objective: Navigation systems create a connection between imaging data and intraoperative situs, allowing the surgeon to consistently determine the location of instruments and patient anatomy during the surgical procedure. The best results regarding the target registration error (measurement uncertainty) are normally demonstrated using fiducials. This study aimed at investigating a new registration strategy for an electromagnetic navigation device. Methods: For evaluation of an electromagnetic navigation system and comparison of registration with screw markers and automatic registration, we are calculating the target registration error in the region of the paranasal sinuses/anterior and lateral skull base with the use of an electromagnetic navigation system and intraoperative digital volume tomography (cone-beam computed tomography). We carried out 10 registrations on a head model (total n = 150 measurements) and 10 registrations on 4 temporal bone specimens (total n = 160 measurements). Results: All in all, the automatic registration was easy to perform. For the models that were used, a significant difference between an automatic registration and the registration on fiducials was evident for just a limited number of screws. Furthermore, the observed differences varied in terms of the preferential registration procedure. Conclusion: The automatic registration strategy seems to be an alternative to the established methods in artificial and cadaver models of intraoperative scenarios. Using intraoperative imaging, there is an option to resort to this kind of registration as needed.

Download Full-text