493 One and Two-Level Robotic MIS TLIF With Expandable Implants Demonstrates a Favorable Safety Profile and Improved Alignment Parameters

Abstract

INTRODUCTION: Minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) is an established technique, but continues to evolve with the development of expandable titanium cages and robotic screw insertion. METHODS: This retrospective case series assessed clinical data, complications, and radiographic outcomes at short term follow-up. Screw placement was performed using intraoperative 3D imaging and robotic navigation, and TLIFs were performed via complete facetectomy from a unilateral trajectory in line with pedicle screws using titanium expandable cages. RESULTS: 22 patients, 32 levels, and 108 inserted screws were analyzed. Implants included curved cages in 14 levels, 2 straight cages (diverging “V” pattern) in 12 levels, and a single straight cage in 6 levels. 21/22 patients (95%) had decreased pain. 4/22 patients (18%) experienced complications including deep infection causing screw pullout (requiring revision), painful radiculopathy, contact dermatitis (glue), and UTI. 108/108 screws (100%) showed excellent position. Increases were observed in average segmental lordosis (4.3 ± 4.9°), anterior disc height (6.6 ± 3.5 mm), posterior disc height (4.1 ± 2.1 mm), and foraminal height (5.0 ± 3.1 mm). Improved alignment was observed in 3/3 patients (100%) with SVA > 50 mm (78.3 ± 13.3 mm to 41.7 ±14.3 mm), 3/4 (75%) with pelvic tilt >=25° (30.3 ± 1.5° to 22.7 ± 4.0°), 5/5 (100%) with lumbopelvic mismatch > 10° (PI – LL: 21.4 ± 2.1° to 9.8 ± 8.5°), 13/13 (100%) with anterolisthesis (6.5 ± 2.3 mm to 1.8 ± 1.9 mm), and 4/4 (100%) with segmental coronal imbalance >5° (8.0 ± 3.2° to 2.8 ± 1.3°). CONCLUSIONS: Robotic MIS TLIF with expandable cages has a favorable safety profile, successful short-term clinical results, and is effective at correcting mild spinal malalignment.