The purpose of this study is to determine whether the morphological consistency of distal fibula could be defined by measurement through radiological assessment as there was doubt regarding the adequacy of anatomical distal fibular plates.

Plain radiographs and computed tomography (CT) images of 300 cases from 2009 to 2012 were reviewed. The distance from the lateral vertex to the tip of the distal fibula and to the lateral margin of the shaft was measured, respectively, in order to understand the shape of the lateral curve of the distal fibula on plain radiographs. The neutral ridge was defined as a point of the lateral ridge located in the center of the antero-posterior diameter and the distance from the tip of the distal fibula to the neutral ridge was measured for determining the shape of the ridge on CT images. The angle of the lateral and posterior surface of the fibular incisura at the level of the neutral ridge was also measured.

A statistically significant difference in the lateral vertex and margin of the fibular shaft on plain radiographs and distance from the tip of the distal fibula to the neutral ridge, angle of the fibular lateral surface on CT images was observed between male and female. The mean distance from the lateral vertex to the tip of distal fibula was 12.2±3.0 mm, to the lateral margin of the fibular shaft was 5.6±1.7 mm, distance from tip of the distal fibula to the neutral ridge was 54.9±6.4 mm, the fibular lateral surface angle was 52.2°±9.1°, and the fibular posterior surface angle was 32.5°±9.3°.

Based on the various radiologic parameters, it was concluded that there was a wide morphological diversity of shape of lateral curve and fibular ridge.