2D geometric model of the human femoral neck in frontal projection

Abstract

In modern society, life expectancy is steadily increasing, at the same time, the number of medial femoral fractures is increasing. The bone-beam system of the proximal epiphysis of the femur has areas of different density throughout, however, these differences are most clearly observed in the neck. The aim of the stidy was to build a two-dimensional parametric model of the human femoral neck to study its bone and beam structure. Material and methods. The study was carried out on 50 macerated femurs and 10 radiographs of human hip joints from the collection of the department of anatomy of I.P. Pavlov Ryazan State Medical University. All bones were without signs of bone pathology and had no growth zones. Age and gender determination was not performed. The material was photographed in frontal projection, then the photographs were transferred to a personal computer and measurements were taken in the Autodesk AutoCAD LT 2012 Commercial New SLM ML03 program. Using a mathematical model, the femoral neck was divided into three figures: "head–neck", "true neck", "neck–trochanteric region". We also measured the angles of the beginning of the increase in the diameter of the femoral neck: to the head (angles α1 and α2); and to the trochanteric region (angles β1 and β2), the angle γ, which characterizes the direction of a number of bundles of the arch system of the proximal epiphysis of the femur, was separately identified. Results. The “true neck” perimeter area was 213.23 [194.31; 250.51] mm2, which occupies 20% in the structure of the integral figure, and the parameters of the “neck–head” and “neck–trochanteric region” perimeters were 355.47 [ 321.47; 420.57] mm2 – 33% and 511.65 [447.11; 583.19] mm2 – 47%, respectively. The median values of the angle α1 were 34.24 [29.38; 40.45]°, angle α2 – 27.27 [22.30; 31.48] °, angle γ – 51.32[46.71; 55.39]°, while the angles β1 and β2 are 39.95 [35.39;42.93]° and 28.65 [25.70; 31.61] ° respectively. Conclusion. The proposed two-dimensional parametric model with the division of the neck into a number of figures makes it possible to mathematically evaluate the position, direction, and distribution of bone-beam structures in the proximal epiphysis.