Study design:

Retrospective Study.

Objective:

This investigation examined matched cohorts of LSF patients undergoing robot-assisted and conventional LSF to compare risk of revision, 30-day readmission, 30-day complications, and post-operative opioid utilization.

Summary of background data:

Patient outcomes and complication rates associated with robot-assisted lumbar spinal fusion (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 post-operative opioid utilization at 1 and 6 months was compared between the cohorts using multivariable logistic regression additionally controlling for age, gender, and Charlson Comorbidity Index (CCI).

Results:

The percent of LSFs that were robot-assisted rose by 169% from 2011-2017, 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 (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%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 lumbar spinal fusion is independently associated with increased risk of revision surgery, infection, instrumentation complications, and post-operative opioid utilization compared to conventional fusion techniques. Further research is needed to investigate long-term post-operative outcomes following robot-assisted LSF. Spine surgeons should be cautious when considering immediate adoption of this emerging surgical technology.

Level of evidence:

3.