Ultrasound measurement of tendons in the palmar metacarpal region of sheep: technique applicability and measurement standardization

Ultrasound measurement of tendons is a clinically and scientifically relevant tool for assessing injury severity and monitoring treatment progress. However, this has not been described for the tendons of the palmar metacarpal region in sheep. This study aimed to describe the ultrasound morphometry of the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and interossei tendon (IT) in the metacarpal region of sheep. Twenty-seven healthy female sheep, approximately 24–60 months of age, were selected. After preparing the thoracic limbs (TL), a transverse ultrasound of the region was performed using a 10 MHz linear transducer. First, the metacarpus was measured and divided into three zones. Then, in the center of each zone, three measurements of the lateromedial diameter (LMD) and dorsopalmar diameter (DPD) of the SDFT, DDFT, and IT were obtained. The cross-sectional area (CSA) was calculated using the formula , where D1 is the LMD and D2 is the DPD. A Student's t-test with a 95% confidence interval was used to compare the means between contralateral limbs. The DDFT showed a statistically significant difference (p<0.05) between the TL. This was not observed in the other structures (p>0.05). The mean values were identical between zones. Thus, the mean values for the SDFT were 0.35±0.03 cm for DPD, 0.99±0.13 cm for LMD, and 0.03±0.00 cm2 for CSA, while for the IT, they were 0.13±0.01 cm for DPD, 0.29±0.03 cm for LMD, and 0.28±0.05 cm2 for CSA. We conclude that this is an easily applicable and reliable technique for evaluating the SDFT and IT.