Introduction: Literature on the utilization of newer robots in minimally invasive spine surgery (MISS) is sparse. We aimed to analyze outcomes of minimally invasive transforaminal interbody fusion (MI-TLIF) using the ExcelsiusGPS (Globus Medical, Inc., Audubon, PA) robotic system. 

Methods: This was a retrospective review of prospectively collected data from a single-surgeon surgical database. Consecutive patients who underwent primary or revision MI-TLIF using ExcelsiusGPS and had a minimum of 1-year follow-up were included. Patient demographics, surgical data (type of surgery, fusion levels, operative time, estimated blood loss [EBL], radiation exposure, and intraoperative complications),M ol.9ikmk0km  postoperative in-hospital data (postoperative length of stay [LOS] and complications), and post-discharge data (Visual Analog Scale- back and leg [VAS], Oswestry Disability Index [ODI], 12-Item Short Form Survey Physical Component Score [SF-12 PCS], return to activities, radiological parameters including pedicle screw accuracy and fusion rate, and complications) were analyzed. The CT-based Gertzbein-Robbins system (GRS) was used to assess pedicle screw accuracy. Fusion status was assessed in the 1-year postoperative CT scan. 

Changes in VAS back, VAS leg, ODI, and SF-12 PCS from preoperative values to the early (<6 months) and late (>6 months) postoperative timepoints were analyzed with Wilcoxon Signed Rank Tests. The percentage of patients achieving minimal clinically important difference (MCID) for these patient-reported outcome measures (PROMs) at the two timepoints was evaluated.

Results: 47 patients were included (53% male, mean age 61.4 years, mean BMI 27.8 kg/m2). 79% were primary surgeries for degenerative disc disease or spondylolisthesis and 21% were secondary surgeries for recurrent same segment stenosis. 94% of patients underwent single-level fusion. In none of the cases was the use of the robot aborted due to any reason. The average operative time and EBL were 105 minutes and 50 mL, respectively. The average radiation dose and time were 38 mGy (17 mGy- surgery, 21 mGy- image capture) and 19 seconds (10 s- surgery, 9 s- image capture), respectively. 70% of patients were discharged on postoperative day one.

194 pedicle screws were placed with 1 dangerous breach requiring revision. Pedicle screw accuracy was 97.7 % and fusion rate was 90%. 1.1% of screws had violated the superior level facet joint.

There were significant improvements in VAS back, VAS leg, ODI, SF-12 PCS with most patients achieving MCID at both the early (<6 months) and late (>6 months) timepoints except SF-12 PCS at the early timepoint. 75% of the previously employed patients returned to work (average 20 days). 90% of the previously driving patients returned to driving (average 19.5 days).

There were no intraoperative complications, 7 in-hospital complications (2 major and 5 minor), and 6 post-discharge complications (3 major and 3 minor). The overall complication rate was 27.3% (12.3% major and 17% minor) and reoperation rate was 6.4%. 

Discussion/Conclusion: Robotic navigation for MI-TLIF leads to superior pedicle screw accuracy, less proximal facet violation, less radiation exposure, and favorable clinical outcomes. Comparative studies with larger sample sizes should be conducted to assess long-term outcomes and cost-effectiveness of robotic navigation in MISS.