Comparison of efficacy of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture / 中华创伤杂志

ABSTRACT

Objective:To compare the effect of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture.Methods:A retrospective cohort study was used to analyze the clinical data of 34 patients with type C thoracolumbar fracture admitted to Henan Provincial People′s Hospital from January 2018 to June 2021, including 23 males and 11 females; aged 42-63 years [(50.4±7.4)years]. The fracture was located at T 11 in 4 patients, T 12 in 10, L 1 in 12, L 2 in 6, T 11~12/L 1 in 1 and T 12/L 1 in 1. Posterior reduction and internal fixation was carried out for all patients, of whom 18 were treated with O-arm assisted pedicle screw placement (navigation group) and 16 with free-hand pedicle screw placement (free-hand group). The operation time, single screw placement time, intraoperative bleeding volume, operation mode and screw placement accuracy were compared between the two groups. The kyphotic Cobb angle, visual analogue score (VAS) and American Spinal Injury Association (ASIA) score were compared between the two groups before operation, at 1 week after operation, at 3 months after operation and at the last follow-up. Postoperative complications were observed. Results:All patients were followed up for 12-29 months [(16.8±6.1)months]. There was no significant difference between the two groups in the operation time, intraoperative bleeding volume and operation mode (all P>0.05). The single screw placement time was (9.4±1.6)minutes in navigation group, but was (10.8±1.5)minutes in free-hand group ( P<0.05). The screw placement accuracy was 97.4% in navigation group, but was 81.5% in free-hand group ( P<0.01). The kyphotic Cobb angle and VAS had no significant differences between the two groups before operation (all P>0.05). The kyphotic Cobb angle in navigation group and free-hand group was (4.3±1.1)° and (5.9±1.1)° at 1 week after operation, (4.4±1.2)° and (5.7±1.3)° at 3 months after operation, and (4.4±1.2)° and (6.8±0.9)° at the last follow-up, decreased significantly from that before operation [(21.8±3.1)°, (22.2±3.2)°] (all P<0.01). The kyphotic Cobb angle in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The VAS in navigation group and free-hand group was (3.2±0.7)points and (4.1±0.7)points at 1 week after operation, (2.4±0.6)points and (3.0±0.8)points at 3 months after operation, and (1.8±0.9)points and (2.6±0.7)points at the last follow-up, decreased significantly from that before operation [(8.4±0.8)points, (8.3±0.9)points] (all P<0.01). The VAS in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The ASIA score showed no significant difference within and between the two groups before operation, at 1 week, 3 months after operation and at the last follow-up (all P>0.05). Postoperative incision infection occurred in 1 patient in both groups ( P>0.05). Implant failure such as loosening or displacement was not observed in navigation group, and only occurred in 2 patients in free-hand group ( P>0.05). Conclusion:Compared with free-hand pedicle screw placement, O-arm assisted pedicle screw placement in the treatment of AO type C thoracolumbar fracture has advantages of rapid and accurate screw placement, good reduction and notable pain relief.