Body of fibula

The body of fibula denotes its shaft, a slender bone shaped by the attached muscles, resulting in three distinct borders and surfaces:

The borders comprise the prominent sharp anterior border, the medial (or interosseus) border (a.k.a. interosseus crest), and the rounded posterior border.

The surfaces consist of the medial surface (a.k.a. the anterior or anteromedial surface) positioned between the anterior and medial borders, the lateral surface located between the anterior and posterior borders, and the posterior surface, the largest of them all, situated between the medial and posterior borders.

Please be aware that there exists an alternative nomenclature describing the body of fibula with four borders and, consequently, four surfaces. While we will primarily use the new three-border and three-surface naming system to describe the fibula, we have provided a brief explanation of the four-border and four-surface naming system below to avoid any confusion for readers encountering conflicting information online:

The four borders consist of the anterolateral, anteromedial, posterolateral, and posteromedial borders. The anterolateral border corresponds to the anterior border in the three-border nomenclature. The anteromedial border corresponds to the medial (or interosseus) border. The posterolateral border corresponds to the rounded posterior border in the three-border system. The posteromedial border corresponds to an oblique line. In the three border system, the oblique line is considered part of the posterior surface, dividing it into anterior and posterior portions. However, in the four border system, the oblique line is regarded as an independent posteromedial border.

The four surfaces include the anterior, medial, lateral, and posterior surfaces. The anterior surface is situated between the anterolateral and anteromedial borders. The medial surface lies between the anteromedial and posteromedial borders. The posterior surface is located between the posteromedial and posterolateral surfaces. The lateral surface is positioned between the anterolateral and posterolateral surfaces.