BACKGROUND We designed a novel plate for the treatment of posterolateral tibial plateau fractures. We first gathered radiological data of the proximal tibiofibular joint to verify the feasibility of the novel plate and provide an anatomical basis. MATERIAL AND METHODS Tomographic images of 98 healthy human tibias were obtained retrospectively. The width of the lateral tibial plateau, width of the posterolateral tibial plateau to the sagittal plane of the tibial plateau and width of the proximal tibiofibular joint to the sagittal plane of tibial plateau were measured. The proximal posterolateral tibial bone cortex angle and posterolateral slope-diaphysis angle were also calculated. Paired sample t-test was used for comparing men and women, and left and right sides. We used 2 variables for Pearson correlation analysis between the width of the lateral tibial plateau and other length indices. RESULTS There were no statistically significant differences between left and right knees (P>0.05). However, there were statistically significant differences of the 3 length indices between men and women (P<0.05). The length indices were all correlated to the width of the lateral tibial plateau (P<0.01). CONCLUSIONS This study of the lateral tibial plateau has a high accuracy in anatomical measurement, and our novel plate design is feasible based on the data. The study provided anatomical basis for the novel plate.