Robotized access to the medullary cavity for intramedullary nailing of the femur

Abstract

Introduction: The insertion site for an antegrade femoral intramedullary nail in the treatment of a femoral shaft fracture has traditionally been performed using a free-hand technique. An inappropriate starting point can result in suboptimal nail insertion leading to malreduction, or iatrogenic fracture. Furthermore, repeated attempts to establishthe optimal starting point cancause additional soft tissue trauma and radiation exposure. In the following study we compared a robot-guided technique with the standard free-hand technique for establishing the entry point of an antegrade femoral nail. We hypothesized that the robot-guided technique is more reliable and efficient.Methods: A custom-made drill-guide was mounted onto the arm of an industrial robot. Two orthogonal fluoroscopic images were acquired from the proximal femur of five cadaveric human specimens. Images were processed with a specialsoftwarein order to create an enhanced contour-recognition map from which the bone axes were automatically calculated. The drilling trajectory was computed along the extension of the bone-axis. The robot then moved the drill-guide on this trajectory toward the entry point. The drilling was then performed by the surgeon. In the control group, five cadaveric human femora were utilized to manually establish the starting pointusing the free-hand technique.Results: 100% of the intramedullary cavities were successfully accessed with both the robot-guided and the manual techniques. In the manual technique repositioning of the drill was necessary in three out of five cases. The mean number of acquired fluoroscopic images was significantly reduced from 11.6 (manual) to 4 (robot-guided).Conclusion: Robot-assisted drilling ofthe entry-point in antegrade femoral nailingis more reliable and requires fewer radiographic images than the free hand technique. Yet, based on economical and logistical considerations, its application will probably only be accepted when a concomitant application for fracture reduction is available.

Robotic distal locking of intramedullary nailing: Technical description and cadaveric testing

“…As part of a long‐term focus on developing a fully‐robotic platform for long‐bone fracture treatment, we have performed specific tests of each part of the procedure . In this instance, we aimed to test a robotic implementation for distal locking, which is widely recognized as one of the most technically challenging steps of the intramedullary nailing procedure .…”

Comparison of algorithms for automated femur fracture reduction

“…In an effort to improve outcomes after intramedullary nailing of femur fractures, we have worked on developing a comprehensive roboticassisted operative technique. [6][7][8][9][10]13,14,[17][18][19][20][21][22][23] We have previously shown that surgeon-performed telemanipulated fracture reduction is effective and accurate for simple fracture types. To further improve the accuracy of more complex fractures, we have worked on automated fracture reduction algorithms that are able to rearrange the fracture fragments into their optimal position and plan an efficient and minimally traumatic fracture reduction path.…”

“…The continued development of advanced three‐dimensional (3D) imaging techniques, computer navigation and surgical robotics has made it possible to design methods aimed at improving the intramedullary nailing techniques. We have previously described several components of a computer‐assisted robotic framework for intramedullary nailing of the femur, including the successful implementation of telemanipulated 2D and 3D fracture reduction . These techniques are highly accurate for simple fractures, but the effectiveness of the procedure decreases in complex fractures with multiple small fragments and without a clear connection between the main ends of the femur segments.…”

“…We have previously described several components of a computer-assisted robotic framework for intramedullary nailing of the femur, including the successful implementation of telemanipulated 2D and 3D fracture reduction. [6][7][8][9][10] These techniques are highly accurate for simple fractures, but the effectiveness of the procedure decreases in complex fractures with multiple small fragments and without a clear connection between the main ends of the femur segments. Given that smaller fragments cannot be tracked using computer navigation, the surgeon must intuitively guide the reduction using her best guess as to where the fragments should be positioned.…”

Improving the human–robot interface for telemanipulated robotic long bone fracture reduction: Joystick device vs. haptic manipulator

“…Ozwald et al . developed a robotic technique for improving the entry‐point access of antegrade femoral nailing . Lei et al .…”