TiRobot navigation versus conventional minimally invasive percutaneous pedicle screw fixation for treating thoracolumbar spine fractures

Abstract

BACKGROUND: The precision of pedicle screw placement directly impacts the prognosis of minimally invasive surgery for thoracolumbar fractures. Given the technological disparity between TiRobot assisted intelligent navigation and conventional C-arm 2D fluoroscopy, this study focuses on neurologically intact cases to demonstrate the former’s advantages through multidimensional evaluation of screw placement accuracy, surgical efficiency, and perioperative clinical metrics. OBJECTIVE: To compare the clinical efficacy of percutaneous pedicle screw fixation under the guidance of the TiRobot system with traditional percutaneous pedicle screw fixation using "C" arm X-ray fluoroscopy for the treatment of thoracolumbar spine fractures without associated nerve injury. METHODS: Retrospective analysis was conducted on 37 patients with single-segment thoracolumbar fractures treated surgically at the Second Hospital of Shanxi Medical University from November 2022 to March 2024. The trial group (the TiRobot-assisted group) included 18 patients (10 males, 8 females) with a total of 108 pedicle screws; the control group (traditional C-arm fluoroscopy group) included 19 patients (12 males, 7 females) with a total of 114 pedicle screws. General information, operation time, intraoperative blood loss, intraoperative fluoroscopy time, postoperative hospital stay, visual analog scale (VAS) for low back pain, Oswestry Disability Index (ODI), anterior vertebral height percentage, sagittal Cobb angle, screw placement accuracy, and facet joint violation rate were compared between the two groups preoperatively and at 1 week, 6 months, and 12 months postoperatively. RESULTS AND CONCLUSION: (1) There were no significant differences between the two groups in general information, operation time, intraoperative blood loss, postoperative hospital stay, VAS, ODI, anterior vertebral height percentage, or sagittal Cobb angle (all P > 0.05). (2) The intraoperative fluoroscopy time in the trial group was significantly shorter than that in the control group (P < 0.05). (3) The screw placement accuracy in the trial group was 95.4% and the facet joint violation rate was 2.8%, while in the control group these were 86.0% and 10.5%, respectively; the differences were statistically significant (P < 0.05). (4) TiRobot-assisted navigation for percutaneous pedicle screw fixation offers higher screw placement accuracy, better protection of posterior spinal structures such as facet joints, and significantly reduces radiation exposure time for both patients and medical staff compared to conventional methods.

1. Introduction

The thoracolumbar junction, as a transition zone from the relatively rigid thoracic spine to the more mobile lumbar spine, is subjected to significant biomechanical stress and is therefore more prone to fractures [1-3]. If not treated promptly, patients may experience persistent thoracolumbar pain or kyphotic deformity, and in severe cases, neurological deficits leading to muscle weakness, dysfunction, or even paralysis [4]. In clinical practice, the Thoracolumbar Injury Classification and Severity Score (TLICS) plays an important role in guiding treatment decisions. When the TLICS score is greater than 4 and the spine is significantly unstable, surgical intervention is recommended; when the score is less than 4, conservative treatment is preferred; and when the score equals 4, the decision is based on the patient's specific clinical condition [5-6]. Anterior and posterior pedicle screw fixation is the mainstream surgical approach, achieving vertebral reduction through a screw-rod system, effectively restoring spinal stability and correcting kyphotic deformity.

Spinal fracture reduction and fixation can be performed via open or minimally invasive approaches. Open surgery requires extensive dissection of paraspinal muscles, often leading to significant tissue damage, greater blood loss, longer operative time, and slower recovery [7-8]. With the advancement of minimally invasive techniques, the Wiltse paraspinal approach, which uses blunt dissection between the multifidus and longissimus muscles, significantly reduces muscle injury and lowers the incidence of postoperative chronic pain, offering advantages such as less trauma, reduced bleeding, and faster rehabilitation [9]. Percutaneous pedicle screw fixation, as proposed by Magerl et al., is minimally invasive with less tissue damage, reduced blood loss, lower infection risk, and quicker recovery; however, it is technically demanding due to the lack of direct visualization, and often requires multiple fluoroscopic images, increasing radiation exposure for both patients and medical staff [10-11]. Therefore, improving screw placement accuracy, shortening operative time, and reducing radiation exposure have become core technical goals in the treatment of thoracolumbar fractures.

In recent years, the integration of artificial intelligence and medical engineering has promoted the development of orthopedic robot navigation systems, which enhance surgical precision and safety through three-dimensional preoperative planning, real-time navigation, and precise positioning. Currently, the main orthopedic robots in clinical use include Mazor Renaissance (Mazor Robotics, Israel), ROSA (Zimmer Biomet, France), and the TiRobot (Beijing TINAVI Medical Technologies, China) [12]. The TiRobot, leveraging a computer navigation system and a stable robotic arm, eliminates the instability caused by surgeon tremor and hand movements, thereby improving surgical precision. It has been widely adopted in many hospitals in China [13]. This study retrospectively analyzes 37 patients with single-segment thoracolumbar fractures without neurological deficits who underwent surgery at the Second Hospital of Shanxi Medical University from November 2022 to March 2024, comparing the clinical efficacy of TiRobot-assisted navigation versus conventional C-arm fluoroscopy in percutaneous pedicle screw fixation.