Pre-Fusion Shape Changes of Humeral Metaphyseal Surfaces: A New Method for Assessing Maturity and Age in Non-Adult Skeletal Individuals

Objectives

The current research delves into the use of 3D geometric morphometric for assessing shifts in maturity within both the proximal and distal humeral metaphyses. It mainly focuses on establishing correlations between these shifts and the shape changes observed in the corresponding epiphyses established through radiographic imaging.

Material and Methods

The total sample comprises 120 right-side proximal humeral metaphyses and 91 right-side distal humeral metaphyses. The entire sample was categorized into four maturity groups for the humeral distal metaphysis and five maturity groups for the humeral proximal metaphysis based on the appearance and subsequent changes in shape and size. All humeri were scanned using 3D surface scanning devices. Two different 3D template configurations were created to capture the shape changes during the development of the proximal and distal metaphyses. We conducted an analysis of shape (Procrustes shape coordinates) and an analysis on the form space in order to assess both maturity changes of humeral metaphyses and their interrelationship with size.

Results

The shape changes explained by PC1 are crucial in establishing the maturational sequence in both the distal and proximal metaphyses. These shape changes reflect the appearance and subsequent changes in shape and size of their corresponding epiphyses.

Discussion and Conclusions

There is a considerable overlap among different maturity groups related to the gradual nature of the maturational process. However, shape changes in proximal and distal humeral metaphyses are suitable to assess maturity in skeletal specimens.