Regional variations of cortical bone in the humeral head region: A preliminary study

Incidence of proximal humeral fractures dramatically increased over the last decade due to demographic changes. The goal of this study was to analyze regional characteristics of cortical bone in the humeral head region using cortical bone mapping (CBM) technique.

The proximal humerus of 103 healthy volunteers was imaged by clinical computed tomography (CT) scans. Three groups of volunteers were identified according to age: group A (20-39years), group B (40-59years), and group C (>60years). CBM was applied to create color 3D thickness maps for each proximal humerus. Cortical parameters, including the cortical thickness (CTh), cortical mass surface density (CM), and the endocortical trabecular density (ECTD) were measured over humeral head region after nine regions of interest (ROI) were defined.

Cortical bone structure of the humeral head region varied dramatically in cross-section independent of age, with significant cortical thinning at the posterior wall. Particularly, notable cortical thinning was also found in the distal end of lateral wall at 60years of age or older. The degree of regional variability of cortical properties within lateral wall tended to diminish with age.

Substantial regional variations in cortical bone structure at humeral head region were observed quantitatively in this study. These morphologic data provided useful information on clinical medicine such as surgical fixation.