A method and system for intraoperative, image-based reduction control for long bone shaft fracture treatment. The method includes preoperative steps of a) implanting markers into the proximal fragment and into the distal fragment of the broken bone, b) creating a 3D reference model of bone by taking a CT scan of the healthy bone, a CT scan of the broken bone and c) defining landmarks in the reference model based on the marker positions. The method further includes intraoperative steps of d) extracting the 3D position of the same landmarks from a series of 2D fluoroscopic images, using a reference object and e) comparing the positions the preoperatively defined landmarks and the positions of the intraoperatively extracted landmarks to calculate the malalignment of the fracture fragments.
