This case is a 9yo Irish Draught gelding.
The gelding presented with a grade 4/10 left forelimb lameness.
Clinical findings:
• A palmar digital nerve block abolished the lameness.
• A swelling was identified at the dorsolateral aspect of the coronary band.
Imaging findings:
Radiographs identified some irregular new bone at the dorsolateral aspect of the middle phalanx. A soft tissue injury was suspected and MRI examination was recommended.
On MRI an osseous defect at the dorsolateral aspect of the middle phalanx was identified (red arrows) at the site of origin of the lateral collateral ligament of the distal interphalangeal joint. There was marked osseous fluid signal at this level (green arrows).
The lateral collateral ligament of the distal interphalangeal joint is moderately enlarged with regions of hyperintense fluid signal within the ligament (pink arrows) consistent with moderate desmopathy of the ligament. Moderate to marked soft tissue swelling is seen dorsolaterally (blue arrows).
Diagnosis:
This is consistent with partial or complete avulsion of the lateral collateral ligament of the distal interphalangeal joint. There is also marked desmopathy of the lateral collateral ligament of the distal interphalangeal joint.
