Accuracy and Efficiency of Robot-Assisted Pedicle and S2AI Screw Cannulation for Adult Thoracolumbar and Lumbar Fusion: Success and Failure in a Single Surgeon’s First 110 Cases and 816 Pedicles

Presented at SMISS Annual Forum 2018
By A. Ha
With Xiaobang Hu ,

Disclosures: A. Ha None Xiaobang Hu None,


There is increasing interest in robotic-assisted pedicle screw placement. Safety, efficacy, efficiency, and cost-effectiveness are paramount when evaluating robotic-assisted spine surgery. Here we present a single surgeon’s first 110 patients undergoing thoracic and lumbar pedicle and S2AI instrumentation with robotic assistance.


Robotic-assistance for pedicle screw cannulation is a safe and accurate technique in posterior spinal instrumentation.


We reviewed adult patients undergoing posterior lumbar/thoracolumbar instrumentation and fusion with robotic assisted pedicle cannulation. The Mazor X and Renaissance systems were both utilized (Mazor Robotics, Caesarea, Israel). All cases were performed at a single academic institution from 2016 to 2018 by a single surgeon for both degenerative and deformity diagnoses. Reports were independently generated for each case to record the success/failure of each pedicle screw. Overall rate of successful pedicle cannulation was evaluated and compared between the two robot models. Pedicle screw placement was checked by fluoroscopy, palpation of the screw tract, and intra-operative CT (27) in deformity cases.


110 adult patients underwent lumbar or thoracolumbar fusion with robotic assistance over the study period (Table 1). 75% of cases were for degenerative diagnoses and 25% were performed for deformity correction. 75% were “open” vs. 25% minimally invasive (MIS). 816 pedicles were instrumented; 769 (94.2%) were accurately placed, while 47 (5.8%) pedicle screws were determined to be misplaced requiring re-direction using freehand technique (open) or fluoroscopy (MIS). 10 (1.2%) screws were aborted due to registration failure. Use of the robot was aborted/dismounted completely in 10 (9.1%) cases due to registration failure. 24 (6%) pedicles were “missed” using the Mazor X vs. 23 (5.4%) using the Renaissance (p=0.33). 68 of 72 (94%) S2-Sacral Alar-Iliac screws were placed successfully.


We report 94.2% accuracy with robot-assisted pedicle and S2AI cannulation in the first 110 patients, 816 pedicles, and 72 S2AI screws by a single surgeon. 5.8% of pedicle screws requiring re-direction either after initial cannulation or screw placement.