Comparative evaluation of postoperative outcomes and expenditure between robotic and conventional single-level lumbar fusion surgery: a comprehensive analysis of nationwide inpatient sample data
Authors: Maman David , Mahamid Assil , Finkel Binyamin , Gan-Or Hadar , Fournier Linor , Berkovich Yaron , Behrbalk Eyal 
Published: May 2024

Abstract
Introduction
In this study, we investigate the evolution of lumbar fusion surgery with robotic assistance, specifically focusing on the impact of robotic technology on pedicle screw placement and fixation. Utilizing data from the Nationwide Inpatient Sample (NIS) covering 2016 to 2019, we conduct a comprehensive analysis of postoperative outcomes and costs for single-level lumbar fusion surgery. Traditionally, freehand techniques for pedicle screw placement posed risks, leading to the development of robotic-assisted techniques with advantages such as reduced misplacement, increased precision, smaller incisions, and decreased surgeon fatigue. However, conflicting study results regarding the efficacy of robotic assistance in comparison to conventional techniques have prompted the need for a thorough evaluation. With a dataset of 461,965 patients, our aim is to provide insights into the impact of robotic assistance on patient care and healthcare resource utilization. Our primary goal is to contribute to the ongoing discourse on the efficacy of robotic technology in lumbar fusion procedures, offering meaningful insights for optimizing patient-centered care and healthcare resource allocation.

Methods
This study employed data from the Nationwide Inpatient Sample (NIS) spanning the years 2016 to 2019 from USA, 461,965 patients underwent one-level lumbar fusion surgery, with 5770 of them having the surgery with the assistance of robotic technology. The study focused primarily on one-level lumbar fusion surgery and excluded non-elective cases and those with prior surgeries. The analysis encompassed the identification of comorbidities, surgical etiologies, and complications using specific ICD-10 codes. Throughout the study, a constant comparison was made between robotic and non-robotic lumbar fusion procedures. Various statistical methods were applied, with a p value threshold of < 0.05, to determine statistical significance.

Results
Robotic-assisted lumbar fusion surgeries demonstrated a significant increase from 2016 to 2019, comprising 1.25% of cases. Both groups exhibited similar patient demographics, with minor differences in payment methods, favoring Medicare in non-robotic surgery and more private payer usage in robotic surgery. A comparison of comorbid conditions revealed differences in the prevalence of hypertension, dyslipidemia, and sleep apnea diagnoses—In terms of hospitalization outcomes and costs, there was a slight shorter hospital stay of 3.06 days, compared to 3.13 days in non-robotic surgery, showcasing a statistically significant difference (p = 0.042). Robotic surgery has higher charges, with a mean charge of $154,673, whereas non-robotic surgery had a mean charge of $125,467 (p < 0.0001). Robotic surgery demonstrated lower rates of heart failure, acute coronary artery disease, pulmonary edema, venous thromboembolism, and traumatic spinal injury compared to non-robotic surgery, with statistically significant differences (p < 0.05). Conversely, robotic surgery demonstrated increased post-surgery anemia and blood transfusion requirements compared to non-robotic patients (p < 0.0001). Renal disease prevalence was similar before surgery, but acute kidney injury was slightly higher in the robotic group post-surgery (p = 0.038).

Conclusion
This is the first big data study on this matter, our study showed that Robotic-assisted lumbar fusion surgery has fewer post-operative complications such as heart failure, acute coronary artery disease, pulmonary edema, venous thromboembolism, and traumatic spinal injury in comparison to conventional methods. Conversely, robotic surgery demonstrated increased post-surgery anemia, blood transfusion and acute kidney injury. Robotic surgery has higher charges compared to non-robotic surgery.