Comparing Lumbar Disc Space Preparation With Fluoroscopy Versus Cone Beam-Computed Tomography and Navigation: A Cadaveric Study

In vitro Comparison of Endplate Preparation in Biportal Endoscopic and Microscopic Tubular Transforaminal Lumbar Interbody Fusion Procedures

BACKGROUND

Successful spinal fusion heavily depends on the condition of endplate preparation in transforaminal lumbar interbody fusion (TLIF). The microscopic tubular (MT) approach offers a fixed surgical field outside the body and primarily relies on tactile feedback for endplate preparation. In contrast, the biportal endoscopic (BE) approach offers a flexible surgical field of view inside the body, allowing for direct visualization of the entire process of endplate preparation. These differences may affect the adequacy and completeness of endplate preparation.

PURPOSE

To evaluate the adequacy and completeness of endplate preparation in BE- and MT-TLIF.

STUDY DESIGN/SETTING

Anatomical study of human cadavers.

OUTCOME MEASURES

A quantitative assessment was performed using digital imaging software to calculate the percentage of the prepared endplate area (Prep %), which evaluated the adequacy of endplate preparation by comparing the prepared endplate cross-sectional area to the total endplate area. The entire endplate was divided into a grid of 6×8 pixels to evaluate the completeness of endplate preparation. Each pixel was qualitatively scored on a 4-point scale (0-3 points) based on the extent of bony endplate exposure and was counted based on its score. The percentage relative to the total number of pixels (Pixel%) was calculated.

METHODS

Four cadaveric torsos were procured for the study. Three lumbar segments were prepared using BE- and MT-TLIF techniques in each cadaver, totaling twelve intervertebral discs and twenty-four endplates. After completing endplate preparations using each approach, the lumbar spines were excised from the cadaveric torsos. Each disc space of the lumbar spine was dissected and split open in the axial plane at the center to expose the cranial and caudal endplates. These endplates were digitally photographed, followed by a quantitative and qualitative assessment of endplate preparation. The difference between the two approaches was then evaluated.

RESULTS

In terms of adequacy of endplate preparation, the Prep% was significantly larger with the BE than with the MT approach (55.10%; 44.94%; p=0.001). Notably, when the entire endplate was divided into quadrants for analysis, the BE approach had significantly larger Prep% in the contralateral anterior and contralateral posterior quadrants (p<0.001). In evaluating the completeness of endplate preparation, the Pixel% with complete endplate exposure (3 points) was significantly higher with the BE approach than with the MT approach (15.60%; 5.93%; p<0.001). There was no significant difference in the Pixel% scored as 0, 1, or 2 points (p>0.05).

CONCLUSION

The results of this study indicate that the BE approach provides significantly better adequacy and completeness of endplate preparation than the MT approach in TLIF surgery.

CLINICAL SIGNIFICANCE

The improved adequacy and completeness of endplate preparation using the BE approach could translate into better fusion outcomes in TLIF surgery. The BE technique may allow for a more thorough preparation of the endplate, reducing the risk of fusion failure and cage subsidence.

Comparing Efficacy of Lumbar Disc Space Preparation via an Anterior-to-Psoas Approach Between Intraoperative Conventional Fluoroscopy and Computed Tomographic-Based Navigation System: A Cadaveric Study

OBJECTIVE

To compare the efficacy of intervertebral disc space preparation via an anterior-to-psoas (ATP) approach using conventional fluoroscopy (Flu) and computer tomography (CT)-based navigation by evaluating the disc remaining area.

METHODS

We equally assigned 24 lumbar disc levels from 6 cadavers into Flu and CT-based navigation (Nav) groups. Two surgeons performed disc space preparation using the ATP approach in both groups. Digital images of each vertebral endplate were obtained, and the remaining disc tissue was calculated in total and in quadrants. Operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, and access angle were recorded.

RESULTS

The overall percentage of remaining disc tissue was significantly less in the Nav group than in the Flu group (32.7% vs. 43.3% respectively, P < 0.001). A significant difference was found in the posterior-ipsilateral (4.2% vs. 7.1%, P = 0.005) and posterior-contralateral (6.1% vs. 10.9%, P = 0.002) quadrants, respectively. No significant between-group difference was found concerning operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, or access angle.

CONCLUSIONS

Intraoperative CT-based navigation may improve vertebral endplate preparation quality for an ATP approach, especially in the posterior quadrants. This technique may offer an effective alternative disc space and endplate preparation methods and may help enhance the fusion rates.

A pilot study of endoscope-assisted MITLIF with fluoroscopy-guided technique: intraoperative objective and subjective evaluation of disc space preparation

BACKGROUND

Adequate discectomy and endplate preparation are extremely crucial steps for spinal interbody fusion. Minimally invasive transforaminal lumbar interbody fusion MITLIF technique is safe and effective. However, concerns exist regarding sufficient disc space preparation from unilateral access. The purpose of this study, was to demonstrate our preliminary experience in objective and subjective evaluation of disc space preparation intraoperatively during endoscope-assisted MITLIF with fluoroscopy-guided, describing some of its possible advantages, and analyzing its safety and feasibility.

METHODS

From March 2018 to July 2019, three patients with degenerative spinal stenosis with radiculopathy and instability underwent endoscope-assisted MITLIF with fluoroscopy-guided. Patients' demographic data, clinical parameters, subsidence, and fusion were collected.

RESULTS

Patients were successfully treated by endoscope-assisted MITLIF with fluoroscopy-guided at single-level or two-level. Symptoms improved postoperatively in all patients, and no complications occurred during follow-up. No cage subsidence was observed. At 6-month postoperatively, there was bony fusion observed on computed tomography in two patients.

CONCLUSION

Endoscope-assisted MITLIF with fluoroscopy-guided is a safe and feasible technique to improve visualization during discectomy and endplate preparation objectively and subjectively, possibly increasing fusion rate and early time to fusion.

Minimally Invasive Transforaminal Lumbar Interbody Fusion With Intraoperative Fluoroscopy for Disc Space Preparation: Analysis of Fusion Rate and Clinical Results

BACKGROUND

Meticulous disc space preparation is an important step toward ensuring arthrodesis in the interbody fusion procedure. Although minimally invasive techniques are becoming increasingly advanced in lumbar interbody fusion, concerns exist regarding adequate discectomy and sufficient endplate preparation from a transforaminal lumbar approach.

OBJECTIVE

To describe the radiographic and clinical outcomes of single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using the intraoperative fluoroscopy-guided method for disc space preparation.

METHODS

This is a retrospective study of 25 patients operated between June 2016 and Dec 2017. The radiographic outcomes included the intraoperative percentage of disc space preparation, fusion, and subsidence. Percentage of disc space preparation was calculated through intraoperative fluoroscopic imaging. Clinical outcomes included visual analog scale (VAS), Oswestry Disability Index (ODI), and satisfaction rate.

RESULTS

Mean age of patients was 62.9 yr. The mean follow-up period was 22 mo. Mean extents of disc space preparation were 61.5% in the anteroposterior view and 80.3% in the lateral view. Fusion rates were 86% and 92% at 6 and 12-mo postoperatively, respectively. All patients showed clinical improvement according to VAS and ODI.

CONCLUSION

MI-TLIF with intraoperative fluoroscopy-guided disc space preparation is shown to lead to potentially improved fusion rate. It is a safe and effective surgical method for degenerative lumbar disease. Additionally, in cases of cage subsidence caused by the endplate violation during disc space preparation, thorough sufficient bone grafting of the defect region avoids pseudoarthrosis.