Predictors of cost of admission for robot-assisted pedicle screw placement

Objective: The authors investigated the predictors of cost of admission (CoA) for robot-assisted pedicle screw placement to assess the value of robotic systems in spine operations.

Methods: Demographic, operative, and postoperative variables were retrospectively collected from 506 patients undergoing robot-assisted spine surgery utilizing the ExcelsiusGPS robot at two high-volume tertiary care centers from 2017 to 2023. Perioperative parameters were evaluated against total hospital admission cost utilizing the Kruskal-Wallis and Wilcoxon rank-sum tests followed by multivariable linear regression.

Results: The majority of patients were female (53.6%), 50-80 years of age (77.7%), and White (73.9%); had at least 1 comorbidity (58.1%); and presented with an average functional preoperative Frankel grade (57.5%). The mean CoA was $69,458 ± $47,910. On univariable analysis, demographic data including sex, age, race, and Frankel grade were not associated with CoA. The presence of a comorbidity, however, was associated with increased CoA (p < 0.001). Intraoperatively, one-third of the operations (31.8%) were revisions from prior operations and were subsequently associated with increased CoA (p = 0.021). Thoracic-level operations constituted roughly one-quarter of the cohort (24.1%) and were also associated with increased CoA (p < 0.001). Intraoperative durotomies occurred in 7.7% of patients, leading to increased CoA (p = 0.003). Extended surgical durations also demonstrated elevated CoA (p < 0.001). Postoperatively, the median length of stay (LOS) was 3 days, and an LOS of greater than 3 days was one of the primary drivers of cost (p < 0.001). Postoperative complications occurred in just 6.3% of the cohort but were also associated with increased CoA (p < 0.001). On multivariable analysis, LOS, number of screws placed, operative duration, and postoperative complications were the primary predictors of increased CoA.

Conclusions: Understanding the drivers of cost in robot-assisted pedicle screw placement is crucial to elucidate the value associated with the use of robotic systems in spine surgery. These results indicate that patient and surgical complexity influence cost and that robotic systems may augment management in spine surgery. Further investigation is warranted to determine the long-term benefits and cost-effectiveness of new technologies compared with traditional techniques in spine surgery.