Refine Your Search

Search Results

Viewing 1 to 2 of 2
Technical Paper

The Effect of Rib Shape on Stiffness

2016-11-07
2016-22-0002
This study investigates the isolated effect of rib shape on the mechanical characteristics of ribs subjected to multiple forms of loading. It aims to measure the variation in stiffness due to shape that is seen throughout the population and, in particular, provide a tool for researchers to better understand the influence of shape on resulting stiffness. A previously published six-parameter shape model of the central axis of human ribs was used. It has been shown to accurately model the overall rib path using intrinsic geometric properties such as size, aspect ratio, and skewness, through shapes based on logarithmic spirals with high curvature continuity. In this study the model was fitted to 19,500 ribs from 989 adult female and male CT scans having demographic distributions matching the US adult population. Mechanical loading was simulated through a simplified finite element model aimed at isolating rib shape from other factors influencing mechanical response.
Technical Paper

Patterns of Acetabular Femoral Head Coverage

2011-11-07
2011-22-0018
The size and shape of the acetabulum and of the femoral head influence the injury tolerance of the hip joint. The aim of this study is to quantify changes in acetabular cup geometry that occur with age, gender, height, and weight. Anonymized computed tomography (CT) scans of 1,150 individuals 16+ years of age, both with and without hip trauma, were used to describe the acetabular rim with 100 equally spaced points. Bilateral measurements were taken on uninjured patients, while only the uninjured side was valuated in those with hip trauma. Multinomial logistic regression found that after controlling for age, height, weight, and gender, each 1 degree decrease in acetabular anteversion angle (AAA) corresponded to an 8 percent increase in fracture likelihood (p≺0.001).
X