In this study, three-dimensional finite element models were created from computer tomography data to study lateral impact fractures of the pelvis. The models reflect the complex geometry and material properties of the pelvis. The models were compared to published experimental results for validation. Dynamic analyses of the pelvic structure were performed for different peak forces in the range of 5520 to 15550 N to correspond to the velocities and impulses of real world accidents. The locations of structurally significant regions of the pelvis were identified based upon the stress distribution and upon the energy stored by the pelvis to failure. The impact force which induced fracture of the pelvic bone was 8610 N. The region which failed first in left lateral impact was the right pubic ramus. The fracture pattern was a variant of the lateral compression pelvic injury. The results suggest that the anterior structures of the pelvis are the most sensitive regions. The energy absorbed by the pelvis prior to failure was 8.98 J. The finite element method may be used to determine the strength and energy-absorbing capability of the pelvis for lateral impact loading.

Biomechanical Phenomena↗

PubMedDate not supplied

The effect of ageing on nutrient digestibility by cats fed beef tallow-, sunflower oil- or olive oil-enriched diets.

Nutrient digestibility and absorption decline with age in several mammalian species. The aim of this study was to compare apparent fat digestibility of different dietary fats in young and senior cats. Three diets enriched with either beef tallow (high in saturated fatty acids), olive oil (high in monounsaturated fatty acids) or sunflower oil (high in polyunsaturated fatty acids) were fed to 6 young (3.0+/-0.9y) and 6 senior (11.6+/-1.4y) cats at 300kJ metabolisable energy/kgBW0.75/d in a 3*3 Latin square design. Food and faecal samples collected over two consecutive 7d periods were analysed for fat, protein, moisture, ash, gross energy and fatty acid content. Apparent digestibilities of fat and energy were significantly lower (P=0.03) in senior cats compared to young cats (fat: 0.922 compared to 0.944; energy: 0.848 compared to 0.885, for senior and young cats, respectively) in all three diets. Senior cats exhibited a lower apparent digestibility for all fatty acid groups compared to the younger cats (saturated: 0.932 compared to 0.952; monounsaturated: 0.964 compared to 0.982; polyunsaturated: 0.980 compared to 0.987, for senior and young cats, respectively). Saturated fatty acids had the lowest apparent digestibility in both young and senior cats, and shorter chain fatty acids were digested more easily than the longer chain fatty acids. These results suggest that the age-related reduction in apparent fat digestibility was a general phenomenon affecting all fatty acids, and was not due to one particular fatty acid group.

Aging↗