Bone Abstracts

The aim of the study was to evaluate relationships between morphometric, densitometric and mechanical properties of tarsometatarsus in ostriches (Struthio camelus). Males (n=9) and females (n=15) were kept to slaughter age of 14 months of life to obtain left tarsometatarsus. Using computed tomography technique (Somatom Emotion, Siemens), volumetric bone mineral density (vBMD) of the trabecular (Td) and cortical bone (Cd) were measured. Areal BMD and bone mineral content (BMC) were evaluated with the use of dual-energy X-ray absorptiometry (DEXA). Geometrical properties such as cross-sectional area (A), second moment of inertia (Ix), mean relative wall thickness (MRWT) and cortical index (CI) were derived on the basis of measurements of horizontal and vertical diameters of tarsometatarsus in the midshaft. Using an INSTRON 3367 apparatus (Instron, USA) and three-point bending test, mechanical parameters such as maximum elastic strength (Wy) and ultimate strength (Wf) of tibia were estimated. Pearson’s correlation coefficient (r) was determined between all the investigated variables and P<0.05 was considered as statistically significant. Positive correlations of bone weight, BMC, and Ix with final body weight of ostriches were found (P<0.05). BMD was positively correlated with Td, BMC, A, MRWT, CI, and Wf (P<0.05). BMC was positively corretated with bone length, weight, A, Ix, Wy, and Wf (P<0.05). Bone weight was positvely correlated with bone length, A, Ix, and Wf, while bone lenght was negatively correlated with Td (P<0.05). Cross-sectional area was positively correlated with Ix, Wy, and Wf, while Ix was negatively correlated with MRWT, CI (P<0.05). Positive correlation between Ix and Wy was found (P<0.05). Positive correlations between MRWT and CI as well as between Wy and Wf were also found (P<0.05). In conclusion, this study showed numerous interrelationships between morphometric, densitometric and mechanical properties of tarsometatarsus. Thus, this bone may be used as an attractive model for further studies on metabolic response of skeleton to physiological, nutritional, toxicological and pharmacological factors influencing bone tissue metabolism.