A device, a system and a method for determining an anteversion angle of a femoral shaft of a femur are provided. The device includes a provision unit and a processing unit. The provision unit is configured to provide image data of the femur, and wherein the processing unit is configured to determine a longitudinal shaft axis extending through the femoral shaft based on the image data. The processing unit is further configured to determine at least two landmarks of the femur based on the image data, and place a tangent trough each landmark parallel to the shaft axis. The processing unit is configured to determine the anteversion angle of the femoral shaft based on the tangents and the shaft axis of the femoral shaft.