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Introduction: Typically, the axillary arch is defined as a fleshy slip running from latissimus dorsi to the anterior aspect of the humerus. Phylogeny seems to give the most relevant and plausible explanation of this anatomical variant as a remnant of the panniculus carnosus. However, authors are not unanimous about its origin. We report herein the incidence of axillary arch in a series of 40 human female dissections and present an embryologic and a comparative study in three domestic mammals., Materials and Methods: Forty formalin-preserved Caucasian human female cadavers, one rat (Rattus norvegicus), one rabbit (Oryctolagus cuniculus) and one pig (Sus scrofa domesticus) cadavers were dissected bilaterally. A comparative, analytical and a descriptive studies of serial human embryological sections were carried out., Results: We found an incidence of axillary arch of 2.5% (n = 1 subject of 40) in Humans. We found a panniculus carnosus inserted on the anterior aspect of the humerus only in the rat and the rabbit but not in the pig. The development of the latissimus dorsi takes place between Carnegie stage 16-23, but the embryological study failed to explain the genesis of the axillary arch variation. However, comparative anatomy argues in favour of a panniculus carnosus origin of the axillary arch., Conclusions: With an incidence of 2.5% of cases, the axillary arch is a relatively frequent variant that should be known by clinician and especially surgeons. Moreover, while embryology seems to fail to explain the genesis of this variation, comparative study gives additional arguments which suggest a possible origin from the panniculus carnosus.

This paper investigates the characterization and numerical modeling of the elastic behavior of the human humerus bone using a recently developed micromechanical approach coupled to nanoindentation measurements. At first, standard three-point bending experiments were conducted under low static loading, using several humerus diaphysis in order to identify the apparent elastic modulus of the bone in static regime. Then, a drop tower impact experiment was used on the same set of humerus diaphysis specimens, in order to assess the elastic modulus in dynamic regime. These measurements will be used as reference bases for comparison purpose. The originality of this work, lies in the coupling between a two-phase micromechanical approach based on Mori-Tanaka homogenization scheme for cylindrical voids and nanoindentation measurements of the elastic modulus of the bone matrix phase. This model has been implemented using a user defined material subroutine VMAT in ABAQUS© Explicit code. The bone mechanical response prediction using the proposed methodology was validated against previous standard experimental data. Finally, it was shown that the numerical predictions are consistent with the physical measurements obtained on human humerus via the good estimation of the ultimate impact load., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The complex architecture of bone has been investigated for several decades. Some pioneer works proved an existing link between microstructure and external mechanical loading applied on bone. Due to sinuous network of canals and limitations of experimental acquisition technique, there has been little quantitative analysis of three-dimensional description of cortical network. The aim of this study is to provide an algorithmic process, using Python 3.5, in order to identify 3D geometrical characteristics of voids considered as canals. This script is based on micro-computed tomographic slices of two bone samples harvested from the humerus and femur of male cadaveric subject. Slice images are obtained from 2.94 μm isotropic resolution. This study provides a generic method of image processing which considers beam hardening artefact so as to avoid heuristic choice of global threshold value. The novelty of this work is the quantification of numerous three-dimensional canals features, such as orientation or canal length, but also connectivity features, such as opening angle, and the accurate definition of canals as voids which ranges from connectivity to possibly another intersection. The script was applied to one humeral and one femoral samples in order to analyse the difference in architecture between bearing and non-bearing cortical bones. This preliminary study reveals that the femoral specimen is more porous than the humeral one whereas the canal network is denser and more connected., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Abstract: Introduction. – The morbidity of surgery for non-union of the humerus is not insignificant: the aims of this retrospective study were to study the results of these rather difficult procedures and to make some logical suggestions regarding surgical technique. Patients and methods. – Between 1996 and 2000, 21 patients had a surgical procedure for non-union of the humeral shaft. At follow-up, the mean age was 40 years. The causes of the initial trauma were: 12 road accidents, seven standing height falls, one fall from a window, one farm machine accident. The commonest fracture site was the middle third. In 17 procedures, we performed plate osteosyntesis. Three patients were treated by external fixator because of infection. In one patient we used a nail. For the follow-up evaluation, we used the score of the Western Orthopaedic Society. Results. – According to the “WOS” score evaluation, we noted: ten very good results, five good results, three poor results and one bad result. The bad result corresponded to the patient in whom consolidation was not obtained. Discussion and conclusion. – Management of non-union of the humerus should be by immediate surgery. The best treatment of non-union of the humerus is its prevention by correct management of the initial fracture. [Copyright &y& Elsevier]

From 1991 to 1998, 23 humeral fractures has been treated using the Orthofix® external fixator. Average age of the patient was 42 y and average follow-up 55.5 m. Initial trauma was: 13 traffic accidents, four falls at home, two devastating farming accidents, two sports accidents, one aggression and one gun accident. AO classification was used and location of the fracture was classified using Hackethal classification modified by de la Caffinie`re. Majority of fractures were located at the one-third distal humerus and the majority was also comminuted. At follow-up, elbow range of motion was 130°, shoulder range of motion 161°, external rotation 69.5°and internal rotation 92.5°. Using the classification of Stewart and Hundley, eight excellent, seven good, three fair and two bad results were obtained. There were no postoperative radial nerve palsy. Two external fixators had to be removed because of pin mobility. Failures were: non union and pin mobility in one patient which has to be reoperated on; two non unions have been grafted on and plated. There were no malunion in the postoperative X-rays. This device is our favourite for this type of injury because of its rigidity and the possibility of secondary dynamization. The external fixator was removed after union: this explains the long delay of union in our series. [Copyright &y& Elsevier]