Breach Detection in Spine Surgery Based on Cutting Torque

Abstract

The accurate placement of pedicle screws is crucial for various spinal interventions, demanding precise geometric alignment while carrying inherent risks. Studies show that the rate of complications can reach up to 18% in case of imprecise placement of pedicle screws. To enhance the precision and safety of pedicle screw placement, we have developed a robotic system equipped with several sensors and paired with a breach detection algorithm capable of identifying potential breaches in the spinal canal. The breach detection algorithm was conceptualized through an analysis of the cutting torque of the drill system. An ex-vivo experiment was conducted to assess the effectiveness of the developed robotic solution and breach detection algorithm. The data (e.g., cutting torque, position, velocity, etc.) used during the validation were collected by drilling 80 pedicles in fresh porcine vertebrae. The results demonstrated that the proposed algorithm could predict breaches in 96.42% of cases, i.e., the distance between the detected point (drilling stop) and the point of the breach is within 2 mm. In a single instance, the detection occurred earlier than anticipated due to the trajectory being oriented significantly medially, resulting in an initial interaction with the cortical bone at an earlier point.