The fibular notch: an anatomical study

Reduction of the distal fibula into the fibular notch (FN) poses a problem that has not been fully resolved, yet. A number of methods have been developed for the assessment of the position of the fibula in the FN, but none of them is ideal. A majority of authors assess the FN 1 cm above the tibiotalar joint space, without specifying the reason for the choice of this distance. None of the previous studies has addressed at what level the FN is the deepest. Our findings show that it is 4-5 mm above the ankle joint space and verification of this hypothesis has been the aim of this study.

Dry adult tibial bone specimens from the Pachner's collection of the Institute of Anatomy of 1st Faculty of Medicine, Charles University, Prague were used in the study. Height of the FN at its widest point, 3 mm and 10 mm above the articular surface of the distal tibia were measured in each specimen, as well as the depth of the FN at the deepest point, 3 mm and 10 mm above the articular surface of the distal tibia and the distance between the highest point of this surface and the deepest point of the notch.

The mean length of the tibia was 350 mm; the mean height of the FN was 42.5 mm; the mean width of the FN at its widest point was 23.6 mm, at 3 mm above the tibiotalar joint space 22 mm, 10 mm above this articular surface of distal tibia (tibial plafond) 18.9 mm. The mean depth of the notch at 3 mm above the tibial plafond was 3.8 mm, at 10 mm above this surface 4.1 mm. The maximum mean depth of the notch was 4.5 mm, the distance from this point to the highest point of the tibial plafond was 5.3 mm.

The deepest point of the FN lies 5 mm above the articular surface of the tibial plafond, with the mean value of the depth being 4.5 mm. This region is, therefore, ideal for assessment of the position of the distal fibula in the FN.