Anatomy of the fibularis tertius muscle – a cadaveric study

Background
According to anatomical studies conducted on cadavers, the fibularis tertius muscle (FTM) is frequently or consistently present in the population. Some authors claim that the fibularis tertius muscle is present at up to level of 81.5-100%.

Aims
The main objective of the study is to present the anatomy of the FTM by investigating the frequency of occurrence of the FTM and measuring the length of the tendon and belly of this muscle, and revealing possible clinical and academic implications of the relative position of these structures and their anatomical variability based on the cadaveric studies performed on the cadavers unfixed with formalin.

Material and methods
This study included 24 lower extremities from 12 frozen (but not fixed with formalin) cadavers.

Results
In the performed anatomical section, FTM was present in 24 out of the 24 lower extremities – it was present on both right and left lower limbs in each of examined 12 cadavers (100%). The mean overall length of the FTM was 180.3mm, the mean length of the muscle belly was 112.1mm, and the mean length of the tendon was 68.2mm.

Conclusions
In the conducted study, FTM was present on every examined lower extremity. The variability of the muscle's morphological features seems to be worth investigating in future studies due to the interesting features found during preparation.