Automated Robot Assisted Fracture Reduction

The preferred treatment of femoral shaft fractures nowadays is the minimally invasive technique of intramedullary nailing. However, besides its advantages, this technique also has a number of drawbacks like the frequent occurrence of malaligned fracture reductions and high X-ray exposures, especially to the operating team. The aim of our research is to overcome these shortcomings by utilizing 3D imaging and surgical navigation techniques in combination with a robot assisted reduction procedure. Even though telemanipulated reductions as developed in our earlier work can achieve high accuracies for simple fracture types, we show how reductions of more complex fractures can benefit from the developed automated methods by ensuring high reduction accuracies and attaining gentle reduction trajectories. We outline a system, which automatically computes the desired target poses of the fragments from 3D imaging data and focus on the algorithms, which plan reduction paths complying with soft-tissue constraints. In addition we propose how to automatically execute these plans by means of hybrid (position and force/torque) controlled skill primitives. In a feasibility study we finally show the applicability of this approach.