The purpose was to analyze tibial plateau fractures (TPF) by computed tomography (CT) by creating a frequency map (FM). We hypothesized that a FM shows clinically important aspects of involvement that are not expressed in classic classifications. 185 TPF were retrospectively evaluated in this single center study. We created a FM onto an axial template of an intact subarticular tibial plateau and separated the joint surface in 9 areas, counted the frequency of involvement. The FM gives information of location and grade of damage and expressed three major fracture areas in 76%. 5 specific fracture types add up to 51%. The dorsal parts of the tibial plateau are involved in a higher percentage (+8%). True lateral fractures are less often than plane radiographs suggest. An impression was found in 50%. The complexity of TPFs is high, but 5 specific types could be identified in >50%. The complexity is not sufficiently covered in common classifications, especially the dorsal involvement. The FM is a simple and useful tool that complements common classifications and can be used as guideline for surgical treatment.