A rare tendon variation of the fibularis tertius muscle in an adult cadaver

Goral K., İbiş E. C.

12. Anatomi Kış Günleri, Bursa, Türkiye, 29 Ocak - 01 Şubat 2025, ss.81, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Bursa
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.81
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Objective: The fibularis tertius muscle (FT), also known as the peroneus tertius muscle, is a relatively small muscle in the anterior compartment of the leg. It is also described as the fifth tendon of the extensor digitorum longus muscle and terminates on the dorsal surface of the base of the fifth metatarsal bone. The morphology of this muscle, which plays a role in dorsiflexion and eversion of the foot, is highly variable. In this case report, a rare tendon variation related to the distal attachment site of the muscle is reported. Case: In the right lower extremity of a 65-year-old male cadaver dissected for educational purposes, a tendon variation of the FT was noted. In this case, the resultant tendon of the FT was found to split in two just before the insertion point. In this case, the proximal tendon was seen to attach to the base of the fifth metatarsal. The distal tendon was inserted into the fifth metatarsal 12 mm from the attachment point of the proximal tendon fragment. No structural variation was found in the initial tendon and muscle body of the FT with tendon variation. No anatomical variation of the FT was found in the left lower extremity of the same cadaver. Conclusion: The frequency of the variation reported in this case report varies between 1.52% and 7.2% in the literature. FT is widely used as a free muscle flap to treat soft tissue defects and osteomyelitis in the lower extremity. This muscle, which can be used as a graft tissue in reconstructive surgery, is also used in surgical procedures requiring tendon transfer such as pes planus and tenoplasty. We believe that knowledge of the tendon variations of the FT will reduce the complication rate of surgical procedures performed in this region and increase the chances of success.

Keywords: the fibularis tertius muscle, cadaver, variation