TOPOGRAPHIC AND ANATOMICAL RELATIONS OF NERVES AND ARTERIES IN THE THENAR MUSCLES
Authors: Biryuk I. , Khmara T. , Pankiv T. , Kukovska I. , Sykyrytska T. , Stefanchuk V. 
Published: December 2024

The hand has a high functional significance, and it is important to note that today, especially during military operations, it is often subject to injuries. In addition, hand injuries are common both at work and in everyday life. The success of reconstructive operations and restoration of motor functions of the hand largely depends on the extent to which it is possible to preserve the innervation and normal blood supply of the muscles, which is crucial for further rehabilitation and return to normal functioning.
Objective of the research.  To establish the topographical-anatomical relationships of nerves and arteries in the thenar muscles of human fetuses.
Material and methods. Clarification of the intramuscular distribution of nerves and arteries in the muscles of the thenar eminence was carried out on 32 preparations of the hand of human fetuses of 81.0-375.0 mm parietococcygeal length (PCL) using macromicroscopic preparation, injection vessels, and morphometry without external signs of anatomical deviations or congenital malformations of the skeleton, fascial-muscular and vascular-nervous structures of the upper limbs. The study was conducted in accordance with the basic bioethical provisions of the Convention of the Council of Europe on Human Rights and Biomedicine (4 April 1997), the Declaration of Helsinki of the World Medical Association on the ethical principles for scientific medical research involving human subjects (1964 - 2013). ), Order of the Ministry of Health of Ukraine No. 690 of 23.09.2009, and taking into account the Methodological Recommendations of the Ministry of Health of Ukraine "Procedure for Removal of Biological Objects from Deceased Persons Whose Bodies are Subject to Forensic and Pathological Examination for Scientific Purposes" (2018). The Commission on Biomedical Ethics of the Bukovinian State Medical University (Protocol No. 7 dated 16.05.2024) did not find any violations of moral and legal norms in the conduct of research. The research is a fragment of the planned comprehensive topic of the Department of Anatomy, Clinical Anatomy and Operative Surgery and the Department of Human Anatomy named after M.H. Turkevich Bukovinian State Medical University “Regularity of gender-age structure and topographic-anatomical transformations of organs and structures of the body at the pre-and postnatal stages of ontogenesis. Peculiarities of perinatal anatomy and embryotopography” state registration No. 0120U101571).
Results. The research made it possible to establish that in human fetuses, each thenar muscle has a certain source of innervation and blood supply, a certain gate located in the thenar muscles in their proximal third. Flexor pollicis brevis in most fetuses has double innervation – from the median nerve and the deep branch of the ulnar nerve. Abductor pollicis, most often receives innervation from one source – the lateral branch of the median nerve, and very rarely has an additional source – from the superficial branch of the radial nerve. Adductor pollicis is mainly innervated by 1-2 nerve trunks from the deep branch of the ulnar nerve. In 3 cases, this muscle had an additional source of innervation in the form of a thin branch from the median nerve.
Conclusion. In human fetuses, each thenar eminence muscle has a specific source of innervation and blood supply; some thenar muscles are characterized by double innervation. There are usually several sources of blood supply; they can be divided into main – permanent and additional – non-permanent. The entry gates of nerves and arteries into the thenar muscles are located in their proximal third. In the flexor pollicis brevis, abductor pollicis, and adductor pollicis, the portals of nerves and arteries do not coincide. In the extensor pollicis muscles, except the flexor pollicis brevis muscle, the direction of the intramuscular nerves does not coincide with the direction of the intramuscular arteries. In the thenar muscles, large-diameter arteries lie deeper than the nerves. In practical work, the possibility of different innervation options for the thenar muscles should be taken into account.