Clinical and variational evaluation of peroneus tertius muscle.

This research was conducted to define the typology of the peroneus tertius, which is considered to be a part of the musculus extensor digitorum muscle and plays a role in dorsiflexion and eversion of the foot. In addition, another aim of the study was to examine the relationship of the peroneus tertius with the extensor digitorum longus and to investigate the possible effects of the tendon/insertio properties of the peroneus tertius on the fifth metatarsal. In this study; classical anatomical dissection was performed on 30 lower limbs. In this study, various parameters related to muscle origin, insertion, tendon and muscle dimensions were measured. It has been found that PTM was absent in 26.6% of the specimens and in 23.3% (n = 7) of the cases PTM was directly originated from the EDL. In 56.7% of the specimens (n = 17), the PTM tendon was mutually inserted into the dorsomedial surface of the 5th metatarsal and dorsolateral of the 4th metatarsal, while in 10.0% of the specimens it has thin medial bands (2 × 1 mm) towards the 5th digit. At the end of the study, the PTM origin was categorized into three different types and PTM insertion was categorized into five different types. Variation of PTM, muscle morphology and tendon diameter are extremely important in terms of minimally invasive surgical technique. Since the accessory tendon must have the properties close to the tendon that will be replaced, we believe that the results of our research provide unique useful information to clinicians. This study is the cadaver research.