1. Figure, Supplemental Digital Content 3: Displacement measurements in the frontal plane (left), measurements of frontal migration / illustration of measurements of rotation (top right), and measurements of transverse migration (bottom right) (Illustration from Knobe et al. J Orthop Trauma (RoSA in stable trochanteric fractures)) A: Width of proximal fracture gap, B: Width of distal fracture gap, D: Vertical displacement of the femoral head with respect to the shaft, S: Femoral neck shortening along the sliding direction of the implant, a: Distance measured by a digital caliper (Marker A versus Marker Aꞌ, as a result of rotation of the head-neck-fragment), b: Distance from the screw axis to the marker; static rotation α = arcos (1-(a²/2b²))