Awake Minimally Invasive Surgery Transforaminal Lumbar Interbody Fusion Under Spinal Anesthesia: Screw Placement Accuracy and 1 Year Follow-Up

Abstract

Objective: We assessed the accuracy of pedicle screws placed during awake minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) under spinal anesthesia and analyzed outcomes at the 1-year follow-up.

Methods: We included patients who underwent awake MIS-TLIF under spinal anesthesia at an academic center from February 2020 to February 2022. The Gertzbein-Robbins classification was used for screw accuracy rating.

Results: A total of 100 pedicle screws were inserted in 24 patients, with the most common level being L4-5. Median age was 63.5 ± 16.5 (interquartile range) years, 42% male, median body mass index 28 ± 6 kg/m², and median American Society of Anesthesiologists class was 2 ± 1. Two patients underwent a 2-level fusion, and 22 patients underwent a 1-level fusion. Median estimated blood loss was 35 ± 25 mL, median length of stay was 0 ± 1 day, with 54% of patients going home on the day of surgery, and the only intraoperative complication was 1 durotomy. Median procedure time was 112 ± 23.5 minutes, and median operating room time (including the spinal block) was 159.5 ± 32.7 minutes; 67% of the screws were placed with navigation, and 33% were robotic-assisted (Mazor X); 99% of the screws were Gertzbein Robins grade A, and 1% grade E. At the 1 year follow-up, computed tomography showed no evidence of pseudarthrosis, and all patients reported improvement in their presenting symptoms.

Conclusions: Our study shows a high accuracy (99%) of pedicle screw placement in patients undergoing awake MIS-TLIF under spinal anesthesia and significant improvement of their symptoms at 1-year follow-up.

Keywords: Awake fusion; Awake spine; Robotic fusion; Screw accuracy; Spinal fusion.