Navigation of pedicle screws in the thoracic spine with a new electromagnetic navigation system: a human cadaver study

Integrated Optical and Magnetic Navigation for Simplified Percutaneous Transforaminal Endoscopic Lumbar Discectomy: A Novel Approach

OBJECTIVE

This study aims to evaluate the clinical benefits of the integrated optical and magnetic surgical navigation system in assisting transforaminal endoscopic lumbar discectomy (TELD) for the treatment of lumbar disc herniation (LDH).

METHODS

A retrospective analysis was conducted on patients who underwent TELD for LDH at Beijing Chaoyang Hospital, Capital Medical University from November 2022 to December 2023. Patients treated with the integrated optical and magnetic surgical navigation system were defined as the navigation-guided TELD (Ng-TELD) group (30 cases), while those treated with the conventional x-ray fluoroscopy method were defined as the control group (31 cases). Record and compare baseline characteristics, surgical parameters, efficacy indicators, and adverse events between the 2 patient groups.

RESULTS

The average follow-up duration for the 61 patients was 11.8 months. Postoperatively, both groups exhibited significant relief from back and leg pain, which continued to improve over time. At the final follow-up, patients' lumbar function and quality of life had significantly improved compared to preoperative levels (p < 0.05). The Ng-TELD group had significantly shorter total operation time (58.43 ± 12.37 minutes vs. 83.23 ± 25.90 minutes), catheter placement time (5.83 ± 1.09 minutes vs. 15.94 ± 3.00 minutes), decompression time (47.17 ± 11.98 minutes vs. 67.29 ± 24.23 minutes), and fewer intraoperative fluoroscopies (3.20 ± 1.45 vs. 16.58 ± 4.25) compared to the control group (p < 0.05). There were no significant differences between the groups in terms of efficacy evaluation indicators and hospital stay. At the final follow-up, the excellent and good rate of surgical outcomes assessed by the MacNab criteria was 98.4%, and the overall adverse event rate was 8.2%, with no statistically significant differences between the groups (p > 0.05).

CONCLUSION

This study demonstrates that the integrated optical and magnetic surgical navigation system can reduce the complexity of TELD, shorten operation time, and minimize radiation exposure for the surgeon, highlighting its promising clinical potential.

The Utilization of Navigation and Emerging Technologies With Endoscopic Spine Surgery: A Narrative Review

Endoscopic spine surgery (ESS) is growing in popularity worldwide. An expanding body of literature demonstrates rapid functional recovery with reduced morbidity compared to open techniques. Both full endoscopic spine surgery, or uniportal endoscopy, and unilateral biportal endoscopy (UBE) can be employed in conjunction with various navigation and enabling technologies for assistance with localization of anatomic orientation and assessment of the intraoperative target spinal pathology. This review article describes various navigation technologies in ESS, including 2-dimensional (2D) fluoroscopic imaging, 2D fluoroscopic navigation, 3-dimensional C-arm navigation, augmented reality, and spinal robotics. Employment of enabling navigation and emerging technology with the registration of patient-specific anatomy enables clear delineation of anatomic landmarks and facilitation of a successful procedure. Additionally, avoidance of common pitfalls during use of navigation systems in ESS is discussed in this review.

Application of electromagnetic navigation in endoscopic transforaminal lumbar interbody fusion: a cohort study

STUDY DESIGN

Clinical retrospective cohort study.

OBJECTIVES

To explore the application of the electromagnetic navigation system in Endo-TLIF.

MATERIALS AND METHODS

From May 2019 to March 2020, 76 patients with single-segment lumbar spondylolisthesis treated by electromagnetic navigation-assisted Endo-TLIF (NE group) and conventional Endo-TLIF (CE group) were enrolled in the study. Time of pedicle screw implantation, entire operation time, the number of intraoperative X-ray fluoroscopy exposures, total blood loss, incision length, ambulation time, accuracy of pedicle screws, complications, visual analog scale for back and leg pain, Oswestry Disability Index, Japanese Orthopedic Association score and postoperative fusion rates were recorded, respectively.

RESULTS

There were no significant differences in preoperative demographics between the NE and CE groups (P > 0.05). The mean number of intraoperative X-ray fluoroscopy exposures, guidewires insertion, entire operation time, total blood loss and adjustment rate of screws in the NE group were significantly less compared with the CE group (P < 0.05, respectively). There were no significant differences in clinical parameters between the two groups at different time points in the follow-up period (P > 0.05). There was no statistical difference in fusion rates between the two groups. In addition, one case of cage subsidence was observed after surgery in the CE group.

CONCLUSION

Electromagnetic navigation systems could be applied throughout the entire surgical course and ameliorate the shortcomings of the conventional Endo-TLIF technique to reduce radiation exposure, improve accuracy, avoid repetitive operations and shorten surgery time and the required learning curve of the procedure.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Comparison of electromagnetic and optical navigation assisted Endo-TLIF in the treatment of lumbar spondylolisthesis

Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.

A real-time 3D electromagnetic navigation system for percutaneous transforaminal endoscopic discectomy in patients with lumbar disc herniation: a retrospective study

BACKGROUND

In this study, we present a novel electromagnetic navigation (EMN) system for percutaneous transforaminal endoscopic discectomy (PTED) procedure. The objective of this study was to investigate the safety and effectiveness of the PTED with the assistance of the EMN system and compare it with the conventional PTED with the assistance of fluoroscopic guidance (C-arm).

METHODS

The clinical data of 79 patients (32 in EMN group and 47 in C-arm group) undergoing PTED for lumbar disc herniation (LDH) from January to September of 2019 were analyzed retrospectively. The radiation time, puncture time, operation time, visual analog scale (VAS), Oswestry disability index (ODI), modified MacNab criteria, and radiological parameters were recorded in both groups.

RESULTS

Radiation time, puncture time, and operation time were significantly reduced in the EMN group compared with the C-arm group (P < 0.05). Compared with the C-arm group, a steeper learning curve was observed in the EMN group. There were no significant differences between the two groups regarding VAS and ODI scores at different time points (P > 0.05). The satisfaction rates of the EMN and C-arm groups were 90.63 and 87.23%, respectively, but no significant difference was found between the two groups (P > 0.05). There was no significant difference regarding translation and angular motion between the two groups at preoperation and postoperation (P > 0.05).

CONCLUSIONS

The EMN system can be applied to facilitate the PETD procedure. It can significantly reduce the intraoperative radiation time, puncture time, and operation time, and reshape the learning curve of PTED. Due to limitations of a retrospective study, results may need validation with larger prospective randomized clinical trials.

The technical feasibility and preliminary results of minimally invasive endoscopic-TLIF based on electromagnetic navigation: a case series

Background

Uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion (Endo-TLIF) with percutaneous pedicle screw fixation is a promising, minimally invasive method for the treatment of lumbar spondylolisthesis. However, repeated radiation exposure from X-rays and the steep learning curve remain to be improved.

Methods

This retrospective study explored the effects of electromagnetic navigation on improving Endo-TLIF with percutaneous pedicle screw fixation. Clinical information from 42 patients who had received Endo-TLIF with percutaneous pedicle screw fixation from May 2019 to November 2020 was analyzed retrospectively. The procedures were assisted under electromagnetic navigation. The rate of adjustment for guide wires, frequency of X-ray exposure, operative time, accuracy of pedicle screw location, and clinical outcomes were recorded.

Results

The mean follow-up for 42 patients was 11.9 ± 3.1 months. The mean age of the patients was 56.1 ± 9.26 years, with a female/male ratio of 25:17. According to postoperative CT scans and 3D reconstructions, the excellent and good rate of pedicle screws was 96.4%. The rate of adjustment for guide wires under the assistance of electromagnetic navigation was 1.78%, and the frequency of X-ray exposure was 8.27 ± 1.83. The operative time was 167.25 ± 28.16 min, including the duration of guide wire insertion (14.63 ± 5.45 min) and duration of decompression and cage placement (75.43 ± 13.97 min). The duration of hospitalization after operation was 2.59 ± 1.16 days. The preoperative VAS score was 7.51 ± 1.91, and the preoperative ODI was 82.42 ± 8.7%. At the last follow-up, the VAS score was 2.09 ± 0.59, and the ODI was 11.09 ± 3.2%. There were statistically significant improvements in the VAS score and ODI in all patients at the follow-up (p < 0.05).

Conclusions

Electromagnetic navigation can provide accurate positioning and guidance in real time, which improves the surgical efficiency of percutaneous pedicle screw placement and endoscopic decompression in Endo-TLIF with reduced radiation exposures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01148-9.

Long-length tomosynthesis and 3D-2D registration for intraoperative assessment of spine instrumentation

PURPOSE

A system for long-length intraoperative imaging is reported based on longitudinal motion of an O-arm gantry featuring a multi-slot collimator. We assess the utility of long-length tomosynthesis and the geometric accuracy of 3D image registration for surgical guidance and evaluation of long spinal constructs.

METHODS

A multi-slot collimator with tilted apertures was integrated into an O-arm system for long-length imaging. The multi-slot projective geometry leads to slight view disparity in both long-length projection images (referred to as 'line scans') and tomosynthesis 'slot reconstructions' produced using a weighted-backprojection method. The radiation dose for long-length imaging was measured, and the utility of long-length, intraoperative tomosynthesis was evaluated in phantom and cadaver studies. Leveraging the depth resolution provided by parallax views, an algorithm for 3D-2D registration of the patient and surgical devices was adapted for registration with line scans and slot reconstructions. Registration performance using single-plane or dual-plane long-length images was evaluated and compared to registration accuracy achieved using standard dual-plane radiographs.

RESULTS

Longitudinal coverage of ∼50-64 cm was achieved with a single long-length slot scan, providing a field-of-view (FOV) up to (40 × 64) cm², depending on patient positioning. The dose-area product (reference point air kerma × x-ray field area) for a slot scan ranged from ∼702-1757 mGy·cm², equivalent to ∼2.5 s of fluoroscopy and comparable to other long-length imaging systems. Long-length scanning produced high-resolution tomosynthesis reconstructions, covering ∼12-16 vertebral levels. 3D image registration using dual-plane slot reconstructions achieved median target registration error (TRE) of 1.2 mm and 0.6° in cadaver studies, outperforming registration to dual-plane line scans (TRE = 2.8 mm and 2.2°) and radiographs (TRE = 2.5 mm and 1.1°). 3D registration using single-plane slot reconstructions leveraged the ∼7-14° angular separation between slots to achieve median TRE ∼2 mm and <2° from a single scan.

CONCLUSION

The multi-slot configuration provided intraoperative visualization of long spine segments, facilitating target localization, assessment of global spinal alignment, and evaluation of long surgical constructs. 3D-2D registration to long-length tomosynthesis reconstructions yielded a promising means of guidance and verification with accuracy exceeding that of 3D-2D registration to conventional radiographs.

Novel electromagnetic-based navigation for percutaneous transforaminal endoscopic lumbar decompression in patients with lumbar spinal stenosis reduces radiation exposure and enhances surgical efficiency compared to fluoroscopy: a randomized controlled trial

BACKGROUND

Percutaneous transforaminal endoscopic lumbar decompression (PTELD) is an emerging surgical alternative for treating lumbar spinal stenosis (LSS). However, the foraminoplasty procedure often requires repeated fluoroscopy, and endoscopy just offers a local view. No studies have focused on decreasing radiation exposure with electromagnetic navigation assistance. This study introduces a novel electromagnetic-based navigation (EMN) endoscopic system for PTELD in patients with LSS and compares the results in navigation and fluoroscopy groups.

METHODS

Eighty-eight patients with LSS were randomized into either a navigation (44 patients) or fluoroscopy group. Duration of surgery, cannula placement time, radiation dose, blood loss, intraoperative pain assessment, and postoperative hospitalization stay were evaluated. The clinical outcomes were evaluated using a visual analogue scale (VAS), the Oswestry Disability Index (ODI), 6-minute walk test, and modified Macnab criteria.

RESULTS

Eighty-five patients were followed-up for at least 12 months. The duration of surgery and cannula placement time were significantly more efficient in the navigation group (P=0.03 and P<0.001). Intraoperative pain assessment showed significantly less pain in the navigation group (P=0.038). The radiation dose was significantly higher in the fluoroscopy group than the navigation group (P<0.001). The VAS scores for back (P<0.001) and leg (P<0.001) pain improved significantly in both groups after surgery, as did the ODI (P<0.001) scores. Improvements in walking ability and Macnab criteria assessments at the 12-month follow-up, assessed subjective by patient assessments did not differ between the two groups.

CONCLUSIONS

The EMN system used in PTELD for patients with LSS compared to fluoroscopy enhances efficiency for foraminoplasty, reduces intraoperative pain and levels of radiation exposure. It results in outcomes comparable with results using fluoroscopy.

Feasibility of Endoscopic Inspection of Pedicle Wall Integrity in a Live Surgery Model

Background

Perforations of the pedicle wall during cannulation can occur with experienced surgeons. Direct endoscopic visualization has not been used to inspect pedicles previously due to bone bleeding obscuring the camera visualization. The hypothesis of this study was that endoscopic visualization of pedicle wall integrity was technically feasible and would enable identification of clinically significant pedicle breaches.

Methods

A live porcine model was used. Eight lumbar pedicles were cannulated. Clinically significant breaches were created. An endoscope was introduced and was used to inspect the pedicles.

Results

All lumbar pedicles were endoscopically visible at a systolic pressure of 100 mm Hg. Clinically relevant anatomic structures and iatrogenic pathology, such as medial, lateral, and anterior breaches, were identified. There were no untoward events resulting from endoscopic inspection of the pedicle endosteal canal.

Conclusions

Endoscopic inspection of lumbar pedicles was safe and effective. The findings on endoscopic inspection corresponded with the ball-tip probe palpation techniques. Additional techniques, such as selection between 2 tracts, was possible with the endoscopic technique.