Tarsal Osteoarthrosis with Cyst

FEATURED WINNER – Limb Category

Tarsal Osteoarthrosis with Cyst
11-year-old Thoroughbred gelding
Virginia Equine Imaging
Dr. Jack Caldwell

Judges awarded high marks for the scan’s diagnostic clarity and clinical relevance. The CT study provided detailed evaluation of joint degeneration and cystic change, directly supporting diagnosis and case management.

Case Summary

An 11-year-old Thoroughbred gelding was referred for advanced imaging of the tarsus due to persistent right hindlimb lameness. In September 2024, the gelding sustained a fracture of the right lateral malleolus of the tibia during recovery from colic surgery. The fracture fragment was surgically removed one week later; however, intermittent right hindlimb lameness persisted, prompting further diagnostic evaluation.

Diagnosis

Right Hindlimb:
Advanced imaging revealed moderate tarsocrural joint osteoarthrosis and a large talar cyst with articular communication and an associated depression fracture, findings most consistent with a traumatic cyst. Additional findings included multifocal periosteal reaction consistent with regional inflammation and post-surgical change, lateral and medial collateral ligament enthesopathies, mild proximal interphalangeal joint osteoarthrosis, and moderate distal intertarsal joint osteoarthrosis.

Left Hindlimb:
No significant abnormalities were identified.