Quantitative anatomy of the primary ossification center of the radial shaft in human fetuses

Marcin Wiśniewski,Katarzyna Pawlak-Osińska,Michał Szpinda,Mariusz Baumgart,Magdalena Grzonkowska,Zygmunt Siedlecki,Maciej Piec

doi:10.1007/s00276-019-02247-2

Marcin Wiśniewski, Katarzyna Pawlak-Osińska + Show 5 more

Open Access

https://doi.org/10.1007/s00276-019-02247-2

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Abstract

PurposeThe medical literature still lacks studies on the size of the radial shaft primary ossification center, thus preventing us from potentially relevant data in diagnosing skeletal dysplasias, i.e., TAR syndrome, VATER syndrome, Holt–Oram syndrome, Fanconi anemia and Edwards syndrome, frequently characterized by disrupted or retarded fetal growth.Materials and methodsThe size of the radial shaft primary ossification center in 47 (25 males and 22 females) spontaneously aborted human fetuses aged 17–30 weeks was studied by means of CT, digital image analysis and statistics.ResultsWith neither sex nor laterality differences, the best-fit growth dynamics for the radial shaft primary ossification center was modeled by the following functions: y = − 10.988 + 1.565 × age ± 0.018 for its length, y = − 2.969 + 0.266 × age ± 0.01 for its proximal transverse diameter, y = − 0.702 + 0.109 × age ± 0.018 for its middle transverse diameter, y = − 2.358 + 0.203 × age ± 0.018 for its distal transverse diameter, y = –189.992 + 11.788 × (age)2 ± 0.018 for its projection surface area, and y = − 798.174 + 51.152 × age ± 0.018 for its volume.ConclusionsThe morphometric characteristics of the radial shaft primary ossification center show neither sex nor bilateral differences. The radial shaft primary ossification center grows proportionately in length, transverse dimensions and volume, and quadratically in its projection surface area. The obtained numerical findings of the radial shaft ossification center are considered age-specific reference of relevance in both the estimation of fetal ages and the diagnostic process of congenital defects.

Highlights

During weeks 6 and 7 of gestation, the cartilaginous skeleton of the upper limb is designed from the mesenchyme
Having reviewed the professional literature about the ossification of the upper limb bones, we found those of the clavicle [1], humerus [19] and ulna [20] to be precisely quantified and expressed by growth curves
The mean length of the radial shaft ossification center at the range of 17–30 weeks increased from 16.7 ± 0.16 to 35.3 ± 1.5 mm on the right side, and from 16.2 ± 0.1 to 34.8 ± 1.2 mm on the left side, resulting in the linear function y = − 10.988 + 1.565 × age ± 0.018 (R2 = 0.94)—(Fig. 3a)

Summary

Introduction

During weeks 6 and 7 of gestation, the cartilaginous skeleton of the upper limb is designed from the mesenchyme. Except for the clavicle, all the remaining bones of the upper limb ossify from cartilage due to endochondral ossification [1]. The ossification process of the upper limb commences at the end of week 6 of gestation with the formation of the primary ossification center in the middle part of the clavicle. It is the very first ossification center in the human skeleton. Consecutive ossification centers appear in the humeral, ulnar and radial shafts, followed by that in the scapula in week 8 of gestation

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