RESUMO
Objective:To evaluate the accuracy of an ultrasound-guided robot-assisted system for percutaneous facet joint puncture in an animal experiment by registration of ultrasound images and two-dimensional X-ray fluorescence images.Methods:Six specimens of fresh adult sheep lumbar spine were prepared and soaked in gelatin solution. The specimens contained a total of 48 facet joints with 24 ones respectively on the left and right sides. Half of the joints were assigned by the random number table method into a robot-assisted group which were subjected to percutaneous facet joint puncture assisted by the ultrasound-guided robot-assisted system while the contralateral ones into a freehand group which were subjected to percutaneous facet joint puncture by freehand. In the robot-assisted group, the left facet joints were 3 L 1, 3 L 2, 3 L 3 and 3 L 4 ones while the right facet joints were 2 L 1, 3 L 2, 5 L 3 and 2 L 4 ones. In this self-control animal experiment, both the robot-assisted punctures and the freehand punctures were carried out in the same specimen. The puncture success rate, puncture needle adjustment, positioning deviation, orientation deviation and operation time were recorded. Results:The positioning deviation and orientation deviation in the robot-assisted group [(2.21 ± 1.12) mm and 1.51° ± 0.47°] were significantly lower than those in the freehand group [(3.26 ± 1.44) mm and 2.24° ± 0.89°] ( P < 0.05). All the articular facet joint punctures were successfully accomplished for the first time in the robot-assisted group while those required multiple adjustments in the freehand group. In the robot-assisted group, the total operation time [(463.84 ± 34.93) s] was significantly longer than that in the freehand group [(298.40 ± 27.48) s], but the puncture time [(37.97 ± 6.87) s] was significantly shorter than that in the freehand group [(261.61 ± 33.15) s] ( P < 0.05). Conclusion:The ultrasound-guided robot-assisted system for percutaneous facet joint puncture can lead to accurate puncture with limited needle adjustments.