Use of quantitative analysis of sonographic brightness for detection of early healing of tendon injury in horses.

The study investigates whether quantitative analysis of sonographic brightness could be used to identify healing in horse tendons post-injury and if healing process is influenced by equine recombinant growth hormone.

Methodology

• The study subjects were eight clinically healthy Standardbred horses.
• An injury was artificially induced in the left and right superficial digital flexor tendons of each horse using an injection of 2,000 units of collagenase, an enzyme that breaks down collagen and simulates tendon injury.
• Post-injury, half of the horses were given equine recombinant growth hormone, a substance believed to potentially promote tendon healing.
• Sonographic images of the horses’ flexor tendons and ligaments in the metacarpal region (part of the front leg) were recorded on videotape before the injury and weekly for seven weeks post-injury.
• The images were digitized and the sonographic brightness of the tendons and ligaments was calculated.

Results

• The collagenase-induced injury appeared similar to naturally occurring injuries on the sonographic imaging.
• Upon injury, there was a decrease in sonographic brightness of the tendon; however, after the third week, the brightness gradually increased. Regardless, by the seventh week, the brightness had not returned to the pre-injury value.
• The administration of equine recombinant growth hormone did not significantly affect the speed of tendon healing, based on sonographic evaluation or necroscopy (post-mortem examination).

Conclusions

• The study found that changes in sonographic brightness of injured tendons aligned with actual alterations in the tendon structure as healing progressed.
• The researchers concluded that quantitative sonographic brightness could be effectively used to monitor the healing process of equine tendon and ligament injuries and to assess the effectiveness of different treatment approaches.