# Exploring Fully Navigated Minimally Invasive Spine Surgery-Transforaminal Lumbar Interbody Fusion (MISS-TLIF): An Institutional Analysis

## TL;DR

This study examines a new surgical technique for spine fusion that uses 3D navigation to improve precision and reduce complications.

## Contribution

The paper introduces a standardized workflow for fully navigated MISS-TLIF using 3D CT guidance, improving efficiency and accuracy.

## Key findings

- Fully navigated MISS-TLIF achieved accurate screw placement with minimal complications.
- The procedure reduced radiation exposure and improved workflow efficiency.
- Radiological outcomes were consistent with existing literature, showing satisfactory results.

## Abstract

Introduction

Traditionally, percutaneous pedicle screw fixation has been guided using a C-arm. In recent years, 3D CT-based navigation systems have enabled improved visualization and navigated cage placement. However, the sequence of guide wire insertion, screw placement, and cage insertion continues to vary among surgeons, often depending on individual preference. Such variability can disrupt workflow efficiency and underutilize the full potential of navigation technology. A standardized, stepwise approach, initiated with a preoperative 3D O-arm spin and followed by sequential navigation at each step, can optimize workflow and minimize radiation exposure.

Materials and methods

We conducted a retrospective analysis of 44 patients who underwent fully navigated minimally invasive spine surgery-transforaminal lumbar interbody fusion (MISS-TLIF). After a 3D O-arm spin, a single 1-inch skin incision was made at the projected convergence points of the screws, and guide wires were inserted. On the decompression side, a fascial incision through the same skin opening allowed access via a medialized transmuscular TLIF approach. The procedure was performed using loupe magnification, a microscope, or an exoscope, depending on the case. Cage insertion was navigated, and pedicle screws were then placed over the pre-positioned guide wires. Final fixation was completed after confirming placement with a postoperative 3D spin. We analyzed patient demographics, pathology, surgical details, and radiological parameters. Outcomes included pedicle screw perforation, proximal facet joint violation (PFJV), local disc angle, posterior disc height, and pedicle screw convergence angle.

Results

Of the 44 patients included, 35 were female and nine were male. Navigated screw and cage placement was successfully achieved in all cases. The mean estimated blood loss (EBL) was 100 mL, and the average operative time was 124 ± 23.4 minutes. Visualization techniques included loupe magnification (n = 35), operating microscope (n = 9), and exoscope (n = 3). The Oswestry Disability Index demonstrated significant improvement at a mean follow-up of 38.7 ± 13.44 months. A total of 176 pedicle screws were placed, with 164 positioned accurately. PFJV occurred in 7% of screws (2% Grade 2 and 5% Grade 1 breaches). Radiological outcomes, including local disc angle and posterior disc height, were satisfactory and consistent with existing literature. Pedicle screw trajectory demonstrated improved medial convergence.

Conclusions

Fully navigated 3D CT-guided MISS-TLIF is a streamlined procedure that maximizes the capabilities of navigation technology while minimizing workflow disruptions. It overcomes the limitations of conventional C-arm-based techniques and variable surgeon-dependent workflows. This method enhances surgical precision, reduces complications such as pedicle screw breaches and facet joint violations, and facilitates improved screw convergence and cage placement accuracy.