Imaging diagnosis-caudal cruciate ligament avulsion in a horse.

This research explores the case of a two-year-old Standardbred gelding that suffered a severe injury causing lameness in its right hind limb. Utilizing radiography and ultrasonography, an avulsion, or tear, in the caudal cruciate ligament was diagnosed.

Case Background

• The subject of the study was a two-year-old horse, a Standardbred gelding. Prior to the study, the horse ran into a fence during training, resulting in mild lameness in the right hind limb. The lameness mildly improved over a two-week period.
• A second incident occurred when the horse became stuck in the stall and injured its right hind limb. This event led to noticeable lameness and effusion, or swelling, in the stifle joint of the same limb. The horse was then referred to the Atlantic Veterinary College (AVC) for further assessment.

Physical Examination Findings

• Upon examining the horse at AVC, it was found to be Grade 4/5 lame in the right hind limb, signifying severe lameness. The horse also had significant swelling in the joints of the right hind leg. Crepitus, a grating sound or sensation under the skin, was felt during palpation of the affected joint.

Radiography

• Radiography was performed on the right stifle of the horse. Moderate soft-tissue swelling was detected on the cranial aspect of the joint. The femorotibial joint space appeared denser than usual, indicating joint effusion. An osseous fragment, likely bone, was seen close to the tibial plateau.
• In another radiography projection, the bony fragment was faintly visible over the medial intercondylar eminence of the tibia, which appeared more lucent than normal, indicating possible damage to the tibia.

Ultrasonography

• The ultrasound evaluation confirmed a large volume of joint effusion. The caudal cruciate ligament of the horse’s right hind limb had a central hypoechoic region (a region appearing dark on ultrasound images) with loss of fiber pattern. A significant loss of fiber pattern was also seen in the cranial cruciate ligament. The tibial attachment of the caudal cruciate ligament was not seen.

In conclusion, this research article suggested that the horse had suffered femorotibial and femoropatellar joint effusion, as well as damage to both the caudal and cranial cruciate ligaments, ultimately resulting in severe lameness.