Describe a basic ultrasound approach to evaluating the proximal suspensory ligament in the hind limb.

Describe a basic ultrasound approach to evaluating the proximal suspensory ligament in the hind limb.

• A. Place the transducer along the ventral aspect of the fetlock.
• B. Position the horse squarely, place the transducer along the lateral cannon bone at the proximal suspensory region, evaluate fiber pattern and swelling, and compare with the other limb.
• C. Use the transducer on the dorsal aspect of the cannon bone.
• D. Scan with the leg fully flexed in a tight flexion.

Answer: (B)

The basic ultrasound approach centers on using a lateral view over the proximal cannon to visualize the proximal suspensory ligament. Have the horse stand squarely, placing the limb in its natural weight-bearing position. With a linear transducer, start on the lateral aspect of the cannon at the proximal suspensory region and obtain both longitudinal and transverse views so you can trace the ligament from its origin toward its insertion. Look for the fiber pattern: intact, parallel fibers with normal echogenicity and alignment, or any disruption, thickening, or hypoechoic areas that suggest tendinopathy or tearing. Note swelling around the ligament as well, which can accompany inflammatory or degenerative changes. Comparing what you see with the other (uninjured) limb helps distinguish true pathology from normal variation.

This lateral, standing approach gives the clearest, most consistent window to the PSL and avoids distortions from ventral or dorsal windows or from extreme flexion, which can obscure or alter the appearance of the ligament.