Ultrasonography as a method to determine tendon cross-sectional area.

The research article investigates the effectiveness of using ultrasonography to determine the cross-sectional area (CSA) of equine superficial digital flexor (SDF) tendons. The study shows that ultrasonography provides a highly correlated result compared to the traditional ink-blot analysis method, thus, affirming its utility for non-invasive in vivo and in vitro assessments of tendon CSA.

Research Methods

• To verify the feasibility of ultrasonography for CSA measurement, the study compares this method with the conventional ink-blot analysis.
• Experiments were conducted on the SDF tendons of the left forelimbs of 23 horses, both while they were alive and standing erect, and post-euthanasia when the limbs were loaded under tension.
• Ultrasonographic images were acquired at fixed intervals along the length of the tendon, from the base of the accessory carpal bone (DACB) to the proximal sesamoid bones.
• These images were digitised to find values for ultrasonographic CSA and the mean echo intensity (a measure of ultrasonographic brightness that provides data about the structural properties of the tendon).
• After the mechanical tests, a transverse section of the tendon was removed, from which six ink blots were prepared and digitised to measure the morphologic CSA as a comparison metric.

Research Findings

• The CSA measured ultrasonographically while the horses were standing was consistently smaller than those measured under tension and via the ink-blot method.
• A strong linear correlation was observed between the ultrasonographic CSA measurements at standing and under tension, indicating a reliability of this method.
• The same strong correlation was seen when comparing the ink-blot CSA measurements to those obtained using the ultrasonographic method, both at standing load and under tension.
• The mean echogenicity measured through ultrasonography was inconsistently higher than that obtained under tension, indicating a potential limitation of the method.

Conclusion

• The study concludes with the confirmation that ultrasonography is a highly effective, non-invasive tool that can be used in vivo (live animal) and in vitro (isolated tissue) for measuring the CSA of SDF tendons.
• This affirmation of ultrasonography has significant implications for veterinary practices and animal biomechanics research, particularly in assessing and treating tendon injuries in equine species.