Ultrasonography of the solar aspect of the distal phalanx in the horse.

The research conducted ultrasonographic and radiographic examinations on the lower part of the horse’s hoof, known as the distal phalanx, to study the anatomical norms and pathological abnormalities. The study included live horses, cadavers, and horses with diseases of the hoof area, and also evaluated blood flow in the same region using Doppler ultrasonography.

Research Methodology

• The research involved three groups of horses. Group 1 (10 feet from 5 live horses), Group 2 (22 feet from 7 cadaver horses), and Group 3 (9 feet from 5 horses with pathology in their distal phalanx).
• Doctors carried out lateromedial radiographs of the distal phalanx in all groups. In Group 2, the digits were sagitally sectioned after imaging.
• The observations from the ultrasonographic and radiographic examinations of the sagittal solar aspect of the distal phalanx were recorded.
• Doctors measured the distance between the sole and the distal tip of the distal phalanx (A), the solar aspect of the apex of the frog and the distal phalanx (B), and the body of the frog’s surface and flexor surface of the distal sesamoid bone (C) via ultrasonography, radiography, and on the cadaver specimens.

Findings

• Results showed no significant difference between the measurements obtained through radiography, ultrasonography, and direct cadaver analysis concerning points A and C.
• In regard to point B, there was a noticeable statistical difference between the methods of measurement. The variation was attributable to the difference in trimming of the frog apex.
• An examination of the nine feet from Group 3 was conducted using both ultrasonography and radiography and the identified abnormalities were documented.

Blood Flow Evaluation

• Color flow and power Doppler ultrasonography were done on the normal sagittal solar distal phalanx, impar distal sesamoidean ligament, and at the insertion of the deep digital flexor tendon on the facies flexoria of the distal phalanx.
• Power Doppler revealed blood flow at rates between 0.16-0.48 kHz at the tip of the distal phalanx and at 0.16 kHz at the deep digital flexor tendon insertion and in the impar distal sesamoidean ligament.
• Color flow Doppler in normal horses showed average blood flows ranging from 1.8 to 5.4 cm/s at the tip of the distal phalanx and between 1.8-2.0 cm/s at the deep digital flexor tendon insertion and in the impar distal sesamoidean ligament.