Effect of various testing conditions on results for a handheld reference point indentation instrument in horses.

The research compares results from a handheld tool used to measure bone strength in horses’ third metacarpal bones under various conditions. The findings highlight that the tool can be effectively used for in vivo studies to evaluate horses’ bone microfracture resistance, acknowledging a minor constant bias when measurements are done through the skin as compared to exposed bone.

Methods

• For the study, researchers collected third metacarpal bones from the forelimbs of 12 horses.
• Each bone was divided into 6 regions for testing.
• In vivo (on a living animal) and ex vivo (outside a living organism) measurements of bone material strength index (BMSi) were taken, both through skin and directly on the bone to compare the effect of each condition.
• Difference plots were created to compare the BMSi results under assorted conditions.
• Linear regression analysis was used to evaluate the effects of factors like age, sex, and body weight on BMSi. Furthermore, a mixed-model ANOVA was utilized to assess effects of other variables such as age, sex, limb, bone region, and testing condition on BMSi values.

Results

• It was observed that indentation measurements performed on standing sedated and recumbent anesthetized horses and on cadaveric bone showed noticeable regional differences in adult horses’ BMSi values.
• A strong correlation (r2 = 0.71) was found between body weight and BMSi values.
• No significant difference was noted between the in vivo and ex vivo BMSi values. However, a slight constant bias emerged when BMSi was measured through the skin compared to values obtained directly on bone.

Conclusion

• The research concluded that Reference point indentation could be used for in vivo measurement of bone tissue’s resistance to microfracture. But when conducting measurements through the skin, a small constant bias should be taken into account when compared to results for testing directly on exposed bone.