Embodiments of the present invention allow unlimited rotational alignment between two boundaries for alignment with anatomic landmarks while still referencing both posterior condyles for A/P sizing of the distal femur. In particular embodiments, the system provides at least one movable paddle that provides a reference point from the condyles so that the measuring assembly can be aligned to be parallel with the epicondylar axis. Once the measuring assembly is properly angled, the A/P length of the bone can then be measured from a proper reference point.