Analysis of the structural organization of the human hand using anatomical network models

Despite the fact that morphogenetic mechanisms of transformation of the hand during ontogenesis are currently known, the question remains as to how its various anatomical parts are (metacarpal bones, phalanges of fingers) organized into a complex integrated structure. This question remains unanswered for several reasons, including the lack of consensus about conceptual definitions and approaches, including the lack of tools to assess and compare variations in different anatomical parts of the hand. The aim of this study is to assess the structural organization of the metacarpal bones and phalanges of the fingers of the human hand by Anatomical Network Analysis (AnNA). In this study, the functions of the IGRAPH package in the R data analysis programming environment were used for AnNA. The modeling and layout of the network is performed using the Fruchterman-Reingold algorithm. The Spinglass algorithm is used to determine modularity in anatomical networks. For AnNA, X-ray osteometric indicators of the length (joint length) of the metacarpal bones and phalanges of the fingers of 100 middle-aged men and 100 women without traumatic changes, deformities and developmental abnormalities were used. AnNA demonstrates that the organization of the elements of the rays of the hand is represented by two modules – the proximal, which includes (metacarpal bones and proximal phalanges) and the distal, which includes the middle and distal phalanges. When comparing the characteristics of the network models of the hands, it was found that in women the organization of the metacarpal bones and phalanges of the fingers is characterized by higher morphological integration and modularity (modularity 0.31) than in men (modularity 0.45). Morphological modularity and integration are the organizing factors of the structure of morphological parameters of various parts of the hand. The structural organization of the hand is a system consisting of two modules – the proximal (metacarpal bones and proximal phalanges) and the distal (middle and distal phalanges).