The Efficacy of Robot-assisted Modified Minimally Invasive Surgery in the Treatment of Thoracolumbar Fractures in Patients with Ankylosing Spondylitis.

Abstract

Objective: Robotic technology is increasingly used in spine surgery, few studies report its application and outcomes for ankylosing spondylitis (AS)-related thoracolumbar fractures. This study was designed to comprehensively evaluate the efficacy of robot-assisted (RA) modified minimally invasive surgery for treating thoracolumbar fractures in AS patients.

Methods: In this retrospective study, patients diagnosed with thoracolumbar fractures with AS were grouped by surgical techniques into two groups: RA modified minimally invasive surgery group (RA group) or fluoroscopy-assisted open posterior fixation surgery group (FA group). Operation time, intraoperative blood loss, fluoroscopy exposure time, radiation dose, hospital stay, and complications of the two groups were recorded. According to Gertzbein-Robbins criteria, the accuracy of screw implantation was evaluated by CT within 1 week after surgery. During the follow-up period, pain and nerve function were evaluated by visual analogue scale (VAS) and American Spinal Injury Association (ASIA) scale.

Results: A total of 27 patients with thoracolumbar fractures with AS were included in this study, with 13 patients in the RA group and 14 in the FA group. Baseline characteristics showed no intergroup differences. The RA group demonstrated significantly less intraoperative blood loss (287.5±106.1 ml vs. 561±209.8 ml, P < 0.05), longer fluoroscopy exposure time (116.4±16.5 s vs. 35.6±9.1 s, P < 0.05), higher total radiation dose (163.3±25.7 mGy vs. 80.7±24.8 mGy, P < 0.05), and shorter hospital stay (15.9±3.7 days vs. 22.1±5.9 days, P < 0.05) compared to the FA group. Both groups were followed up for 6 months. Post-operatively, VAS decreased significantly in both groups compared to preoperative values (P<0.05). Notably, the RA group exhibited significantly lower VAS scores than the FA group at both one week and three months post - surgery (P<0.05). In terms of neurological function recovery, no significant differences were found between the two groups (P>0.05). In terms of screw accuracy, the RA group (94.2%, 131/159) had a notably larger proportion of clinically acceptable screws (grades A and B) than the FG group (86.8%, 131/151, p < 0.05).

Conclusion: RA modified minimally invasive surgery has merits including reduced blood loss, shortened hospital stay, better pain relief, and improved the accuracy of pedicle screw insertion compared with the FA open surgery in treating thoracolumbar fractures with AS. However, RA technique could increase the intraoperative radiation exposure of patients.