Lutz B, et al. - Experts defined the reliable landmarks in magnetic resonance imaging (MRI) and X-ray images of the knee, which allow comparison of the image modalities. They also calculated the association of the measured epicondylar ratio (ER) in MRI and X-rays of the knee. They noted a reliable determination of ER with MRI and X-ray images of the knee. Findings suggested a fair association of the ER in MRI and X-ray.