Accuracy of robot-assisted iliosacral screw fixation for pelvic posterior ring injuries verified by intraoperative cone beam CT
10.3760/cma.j.cn121113-20250212-00131
- VernacularTitle:术中锥形束CT验证在骨盆后环损伤机器人辅助骶髂螺钉固定中的应用
- Author:
Haotian QI
1
;
Jian JIA
1
;
Zhaojie LIU
1
Author Information
1. 天津市天津医院（天津大学天津医院）创伤骨盆科，天津 300211
- Publication Type:Journal Article
- Keywords:
Pelvis;
Wounds and injuries;
Bone screws;
Robotics;
Minimally invasive surgical procedures;
Tomography, X-ray computed
- From:
Chinese Journal of Orthopaedics
2025;45(8):492-499
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the value of intraoperative cone beam CT (CBCT) in robot-assisted iliosacral screw fixation for posterior pelvic ring injuries.Methods:The 70 patients' data with posterior pelvic ring injuries treated in Tianjin Hospital from March 2020 to October 2023 were retrospectively analyzed. According to the operation method and whether there was intraoperative CBCT verification, the patients were divided into the robot-assisted iliosacral screw fixation group verified by CBCT with 15 cases (robot+CT group), the simple robot-assisted iliosacral screw fixation group with 25 cases (robot group), the freehand iliosacral screw fixation group verified by CBCT with 10 cases (freehand+CT group), and the freehand iliosacral screw fixation group with 20 cases (freehand group). The operation time, the number of intraoperative fluoroscopies, the frequency of guide needle adjustment of each iliosacral screw, Majeed function score, Matta score, fracture healing time, Gras classification of screw position of the four groups were compared, and the iliosacral screw's perforation site were recorded.Results:All patients were followed up, and the follow-up time was 18.89±4.13 months (range, 12-30 months). There were no statistically significant differences in postoperative fracture Matta score, Majeed score and fracture healing time among the four groups ( P>0.05). Specifically, 26, 45, 15, and 32 iliacsacral screws were inserted in the robot+CT group, the robot group, the freehand+CT group, and the freehand group, respectively. The operation times for these groups were 20.19±1.24, 18.78±1.00, 38.13±2.32, and 37.56±1.80 min, respectively. The number of intraoperative fluoroscopies per screw were 20.50±1.37, 18.47±1.06, 39.80±3.56, and 39.34±1.93, respectively. The guide needle adjustment times were 0.54±0.15, 0.47±0.10, 9.33±1.34, and 8.56±0.86, respectively. Statistically significant differences were observed in the above three indicators among the four groups ( P<0.05). There was no statistically significant difference in Gras classification of screw positions among the four groups ( P>0.05). However, in the CBCT verification group (robot+CT group and freehand+CT group), the Gras classification results were 36 screws in Grade I, 4 in Grade II, 1 in Grade III, and 0 in Grade IV. In contrast, in the non-CBCT verification group (robot group and freehand group), there were 48 screws in Grade I, 17 in Grade II, 11 in Grade III, and 1 in Grade IV, with a statistically significant difference (χ 2=8.945, P=0.030). The screw perforation rate in the CBCT verification group was 2% (1/41), with no perforation observed in the robot+CT verification group, compared to 16% (12/77) in the non-CBCT verification group, showing a statistically significant difference (χ 2=4.716, P=0.030). Among the 13 perforating iliosacral screws, two were located in the anterior slope of the sacrum, while 11 were positioned in the posterior and inferior dangerous triangle area of the sacral vertebral body, and the screws were penetrated into the sacral nerve root channel. Conclusions:Robot-assisted iliosacral screw with short operation time, less fluoroscopies and less guide needle adjustments, the screws can be accurately placed according to the plan, with satisfactory clinical outcomes. The penetration sites of robot-assisted iliosacral screw based on two-dimensional X-ray planning were mostly located in the posterior and inferior of the vertebral body at the pedicle level. Intraoperative CBCT can significantly improve the accuracy of sacroiliac screw placement.
