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Micro-hardness distribution of humeral shaft in human skeleton

MetadataDetails
Publication Date2019-08-06
JournalChin J Anat Clin
AuthorsXiaojuan Zhang, Sheng Li, Weiwei Wu, Guobin Liu, Jianzhao Wang
InstitutionsHebei Medical University, Orthopaedic Research

Objective

To measure and analyze the distribution and significance of bone hardness at different levels and directions of humerus shaft.

Methods

Three right humeral shafts from fresh cadaver specimens were included in this study, and were divided into 7 sections perpendicular to the long axis of the humeral shaft.Then, 7 layers (3 mm specimen) were cut with diamond saw, and then divided into humerus upper segment(ā… , ā…” layer), middle segment(ā…¢-ā…¤ layer), lower segment(ā…„, ā…¦ layer), and each layer was divided into anterior, posterior, medial and lateral four areas. Vickers microhardness diamond pressure head was used in the specimen surface to achieve hardness measurement. The distribution of hardness was recorded and analyzed.

Results

A total of 84 parts of humeral shaft were measured and 420 measurements were made. The average hardness of humeral shaft was (47.52±6.01) HV. The overall hardness of the middle humeral shaft was greater than that of the upper and lower humeral shaft(F=11.594, P<0.01). ā…£ level of 7 horizontal layers had the maximum hardness (51.34±7.01) HV. Minimum hardness was ā…¦ level (45.72±6.25) HV. The medial part of middle shaft ā…£hardness was biggest (53.77±8.70) HV, and the minimum hardness occurred in posterior part of shaft section ā…¦ (42.02±7.47 mm) HV. The overall hardness of the posterior humerus (45.28±6.47) HV was lower than that of the lateral humerus (49.12±5.22) HV, the medial humerus (48.28±6.10)HV, and the anterior humerus (47.40±5.55)HV (F=8.347, P<0.01).

Conclusions

There are differences in the micro-hardness of the humerus diaphyseal cortex at different levels and in the orientation of the bone. The data of this distribution can be used to guide the design of 3D-printed implants adapted to the characteristics of bone stress conduction under physiological conditions. It can also provide data support for bone modeling and finite element analysis of bone biomechanical properties under simulated physiological state.

Key words:

Humeral shaft;Ā Bone hardness tests;Ā Vickers hardness;Ā Microhardness;Ā Human skeleton