AR interaction paradigm for closed reduction of long-bone fractures via external fixation

We present an intuitive and ergonomic AR strategy to be coupled with a standard external fixation system aimed at aiding the accurate closed reduction of long-bone shaft fractures. The correct six DOF alignment between the bone fragments can be retrieved by manually repositioning a pair of reference frames constrained to the two extremities of the fixator so as to minimize the geometric distance, on the image plane, between planned/virtual landmarks and their observed/real counterparts. The reduction accuracy was positively validated in vitro in a pilot study that involved an orthopedic surgeon.