Abstract
Background
The Robotic Spinal Surgery System (RSSS) is a robot system designed for pedicle screw insertion containing image based navigation system, trajectory planning system and force state recognition system. The special force state recognition system can guarantee the safety during the operation. The RSSS is helpful in pedicle screw insertion surgery and it will be applied in clinic in the near future. In this study, we evaluated the accuracy and safety of RSSS in an animal experiment.
Methods
Computer tomography (CT) scan data for two anesthetised experimental sheep was acquired using the C-arm and transferred to RSSS for pre-surgery screw trajectory planning. With the assist of RSSS, we inserted 8 and 4 screws into two sheep respectively. Operation time and blood loss during the surgery were recorded, and CT scan was repeated after surgery. Real screw position and trajectory acquired by the post-surgery CT scan and ideal trajectory planned by RSSS were compared to evaluate the accuracy and safety of RSSS. The result is shown as mean±SD.
Results
We planted totally 12 screws into two sheep. The operation time for each sheep is 140min and 110min, and the blood loss is 100ml and 80 ml respectively. Compared with planned trajectory, the average deviation of the entry points in lateral and axial view are 1.07±0.56mm and 1.25±0.42mm and the mean screw deviation angles in later and axial view are 1.78±0.98°and 2.52±1.03°respectively. The RSSS successfully recognised the force stages and guaranteed the safety during the drilling process. There is no penetration in all 12 pedicles, and all the screws fell into group A according to the Gertzbein-Robbins classification.
Conclusion
This animal study demonstrated the accuracy and safety of the RSSS, which also supported the potential application in clinic.
