1. A method for pre-operative orthopedic planning comprising: obtaining only a high-resolution knee-joint scan of a patient; determining hip rotation center and ankle rotation center from anthropometric data based on personal data of the patient; determining a mechanical axis of the knee joint based on the anthropometric data; preparing at least a two-dimensional image model of the knee joint using the knee-joint scan and the determined mechanical axis; and preparing a pre-operative surgical plan based on the image of the knee joint.