Anatomic variability of the nerves of the triceps surae in early human fetuses

Abstract

Background. Establishing fetal anatomical variability of intramuscular nerves and their connections plays an important role in the search for and development of new methods for the diagnostic and treatment posterior region of the leg. Objective – to find out the topographic and anatomical features of the innervation of the triceps surae in human fetuses 4-6 months. Methods. The study was performed on 46 human fetuses 81.0-230.0 mm crown-rump length (CRL) length using macromicroscopic preparation, vascular injection, and morphometry. Results. In early human fetuses, the anatomical variability of the distribution of intramuscular nerves in the thickness of the triceps surae was established, which is due to the variability of the structure and topography of the tibial nerve, structural and functional organization of triceps surae, arterial branching and interneural connections in the thickness of the heads of the gastrocnemius and soleus in fetuses of different and the same age groups, and sometimes in the same fetus. Conclusion. The main source of innervation of the triceps surae is the tibial nerve, which can be presented by a single trunk, main and additional trunks, or several independent trunks. The nerves in the thickness of the triceps are unevenly distributed. The highest concentration of muscular branches of the tibial nerve is determined in the medial head of the gastrocnemius and the medial part of the soleus. Information on fetal topography of intramuscular nerves in the thickness of the right and left triceps surae, as well as forms of their anatomical variability, both in fetuses of different and the same age and sometimes in the same fetus, due to structural-functional organization of the components of the triceps surae, the type of branching of arteries and nerves in the thickness of the heads of the gastrocnemius and soleus. Atypical variants of the topography of the tibial nerve and common fibular nerve in early fetuses, as well as interneural connections in the thickness of the components of the triceps surae, are more common on the right lower leg.