1. A computer-assisted method for determining a dimension of an anatomical feature using two or more fluoroscopic images, the method comprising: displaying a first fluoroscopic image taken of an anatomical feature taken from a first pose, the first image being registered to a common three-dimensional coordinate system; receiving indication of position of at least a first point and a second point within first image corresponding respectively to at least two anatomical landmarks shown within first image; displaying a second fluoroscopic image taken of the anatomical feature from a second angle, the second image being registered to the known three-dimensional coordinate system; indicating with reference to the second image where the anatomical landmarks lie along each of two lines of sight defined by the first and second points within the three-dimensional coordinate system; and determining a distance of a line specified by the first and second points.