Fig. 4

Plain lateral radiograph of a left distal leg including the ankle, with an AO/OTA 42 A2.3 fracture, in a 33.5 years old male patient. Line A represents the axis of the proximal tibial fragment, and line B the axis of the distal tibial fragment; these lines are tangential to the inner or outer border of the anterior cortex, depending on which one of these both borders is the more recognizable on radiograph. Line C represents translation at the level of the fracture center, relative to the axis of the proximal fragment. Line D represents the diameter of the tibia at the level of the fracture. Translation is expressed as a ratio relative to the tibial diameter using the formula Line C/Line D; in this case, 17.9/23.1 = 0.77. Angulation is measured between Lines A and B; in this case, 0.2°