VARIANTS OF THE STRUCTURE, INNERVATION, AND BLOOD SUPPLY OF THE EXTENSOR CARPI RADIALIS LONGUS AND BREVIS IN THE HUMAN FETUS

Abstract

In modern orthopedic practice, some diseases do not cause pronounced functional disorders in the anatomical segments of the limbs but are accompanied by persistent pain syndrome. Among such diseases is lateral epicondylitis, or «tennis elbow». The superfi cial extensor muscles of the posterior group of the forearm begin in the region of the lateral epicondyle of the humerus, in particular the extensor carpi radialis longus and brevis. The deepening of knowledge about the typical and variant structure, topography, blood supply, and innervation of the extensor carpi radialis longus and brevis in human fetuses will allow for improving the approach to carrying out existing fetal surgical techniques, as well as to creating foundation for the development of modern surgical approaches.The study aimed to determine the anatomical variability of the extensor carpi radialis longus and brevis in human fetuses.The study was conducted on preparations of the upper limbs of 36 human fetuses aged 4-10 months using macromicroscopic preparation, vascular injection, and morphometry. The topographical and anatomical features of the extensor carpi radialis longus and brevis in human fetuses are elucidated: variability and bilateral asymmetry of the external shape and size, variability of the places of origin and attachment, variants of blood supply and innervation, patterns of intramuscular distribution arteries and nerves in these muscles. It was found that the zone of the greatest concentration of intramuscular nerves and arteries is the upper and middle third of the bellies of the extensor carpi radialis longus and brevis.Despite the good blood supply of the extensor carpi radial muscles, the relatively small size of their muscle bellies and the transverse course of the intramuscular nerves result in limited opportunities for cutting out muscle fl aps from them. To cut the fl aps on the leg from these muscles, the most rational cuts are in the ascending (transverse) direction, coinciding with the course of the main intramuscular nerves and arteries. Thus, it is possible to use the extensor carpi radialis longus and brevis only for plastic fi lling of the remaining bone cavities of the upper third of the posterior- lateral surface of the radius.The movement of the extensor carpi radialis longus and brevis is also complicated by the fact that their tendons cross the abductor pollicis longus muscle, extensor carpi radialis longus and brevis, and create serious obstacles for the mobilization of these tendons.Knowledge of the classic and variant anatomy of the arteries of the upper limb, and in particular the described topographic and anatomical features of the right brachial radial artery in a 6-month-old fetus, will allow choosing the correct treatment tactics and avoiding iatrogenic injuries during manipulations, diagnostic and surgical interventions.