Risk of Postoperative Complications and Revision Surgery Following Robot-Assisted Posterior Lumbar Spinal Fusion

Daniel S. Yang, BS; Neill Y. Li, MD; Dominic T. Kleinhenz, MD; Shyam Patel, MD; Alan H. Daniels, MD


Spine. 2020;45(24):E1692-E1698. 

In This Article

Abstract and Introduction


Study Design: Retrospective Study.

Objective: This investigation examined matched cohorts of lumbar spinal fusion (LSF) patients undergoing robot-assisted and conventional LSF to compare risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization.

Summary of Background Data: Patient outcomes and complication rates associated with robot-assisted LSF compared to conventional fusion techniques are incompletely understood.

Methods: The PearlDiver Research Program (www.pearldiverinc.com) was used to identify patients undergoing primary LSF between 2011 and 2017. Patients receiving robot-assisted or conventional LSF were matched using key demographic and comorbidity variables. Indication for revision was also studied. Risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization at 1 and 6 months was compared between the cohorts using multivariable logistic regression additionally controlling for age, sex, and Charlson Comorbidity Index.

Results: The percent of LSFs that were robot-assisted rose by 169% from 2011 to 2017, increasing linearly each year (p = 0.0007). Matching resulted in 2528 patients in each cohort for analysis. Robot-assisted LSF patients experienced higher risk of revision (adjusted odds ratio [aOR] = 2.35, P ≤ 0.0001), 30-day readmission (aOR = 1.39, P = 0.0002), and total 30-day complications (aOR = 1.50, P < 0.0001), specifically respiratory (aOR = 1.56, P = 0.0006), surgical site infection (aOR = 1.56, P = 0.0061), and implant-related complications (aOR = 1.74, P = 0.0038). The risk of revision due to infection after robot-assisted LSF was an estimated 4.5-fold higher (aOR = 4.46, 95% confidence interval [CI] 1.95–12.04, P = 0.0011). Furthermore, robot-assisted LSF had increased risk of revision due to instrument failure (aOR = 1.64, 95% CI 1.05–2.58, P = 0.0300), and pseudarthrosis (aOR = 2.24, 95%CI = 1.32–3.95, P = 0.0037). A higher percentage of revisions were due to infection in robot-assisted LSF (19.0%) than in conventional LSF (9.2%) (P = 0.0408).

Conclusion: Robotic-assisted posterior LSF is independently associated with increased risk of revision surgery, infection, instrumentation complications, and postoperative opioid utilization compared to conventional fusion techniques. Further research is needed to investigate long-term postoperative outcomes following robot-assisted LSF. Spine surgeons should be cautious when considering immediate adoption of this emerging surgical technology.

Level of Evidence: 3


Adoption of robotic technology in spine surgery has steadily increased.[1] Surgeons utilizing robotic-assistance in other disciplines such as gynecology, urology, and general surgery have purported benefits in 3D visualization, coordination, decreased radiation exposure, lower risk of infections, postoperative pain, and decreased length of hospital stay.[2] For lumbar spine fusion (LSF), the most common current application of robot-assistance is for a hypothetical increase in accuracy of screw placement.[3] Although some studies report lower rates of pedicle screw repositioning associated with robotic-assisted LSF, the evidence of this finding is inconsistent.[4,5]

Schroder et al[6] performed a literature review of fusion procedures and reported a higher incidence of revision surgery for screw malposition in studies of freehand procedures compared to studies of robot-assisted procedures. However, a randomized controlled study of 60 patients found that 93% of pedicle screws placed had good positions in freehand conventional technique, compared to 85% in robot-assisted LSF.[4] Furthermore, surgical time was significantly shorter using the conventional technique compared to robot-assisted LSF. Other studies have also not found pedicle screw accuracy in robot-assisted LSF to be superior.[5,7–9] These studies have not addressed the impact of robotic assistance on postoperative outcomes such as 30-day readmission and 30-day medical complications nor have they been performed on a national level. Given high costs associated with robotic-assistance, this gap in knowledge and mixed evidence for increased screw placement accuracy encourage further investigation of robot-assistance in LSF.[3]

The purpose of this study was to utilize a robust cohort-matched analysis to examine the impact of robot-assisted LSF on the risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization compared to conventional LSF at the national level. We hypothesized that rate of 30-day complications and readmission would not be decreased in robot-assisted LSF.