Robotic-assisted versus free-hand techniques in adult spinal deformity surgery: a comparative analysis of postoperative outcomes

Abstract

Adult spinal deformity (ASD) represents a challenging area in spinal surgery due to its complexity and potential for postoperative complications. While robotic systems have promised enhanced precision for pedicle screw placement, improved alignment, and potentially fewer complications, the comparative efficacy and morbidity of robotic-assisted (RA) versus free-hand (FH) techniques remains underexplored in the context of ASD. This study aims to compare postoperative outcomes in patients undergoing RA techniques versus FH surgery to manage ASD. A retrospective review was performed and included patients over 18 who underwent a posterior fusion of at least 7 segments from 2015 to 2022. Two separate cohorts were created based on the use of RA or FH. Patients were matched with a 1:5 ratio based on age, sex, utilization of posterior column osteotomy, utilization of three-column osteotomy, utilization of pelvic fixation, number of instrumented levels, and prior lumbar revision. Multivariate logistic regression was used to compare 90-day complications and healthcare utilization. The RA group demonstrated a significantly lower incidence of atelectasis (3.0% vs. 6.8%; p=0.018), respiratory failure (2.7% vs. 6.7%; p = 0.010), pleural effusion (3.3% vs. 7.0%; p = 0.021), and pneumonia (2.1% vs. 6.0%; p = 0.004) compared to the FH group. In addition, the RA group also demonstrated a reduced incidence of spinal cord deficits (1.2% vs. 3.4%; p = 0.048) and a shorter average length of stay (LOS), in days (8.1 +/- 8.3 vs. 10.2 +/- 12.8; p = 0.009). In the present study, we discover that robotic assistance leads to improved short-term outcomes, including reduced rates of pulmonary (atelectasis, pneumonia, pleural effusion, respiratory failure) and neurologic (spinal cord deficit) complications, as well as shorter hospital stays. While RA systems have previously demonstrated technical advantages in pedicle screw placement, this study provides evidence of meaningful clinical benefits as well.

Keywords: Adult spinal deformity; Complications; Free hand; Long segment; Retrospective; Robotic.