EXPRESS: Computed tomographic (CT) diagnosis and subsequent arthroscopic treatment of a coronoid process fracture in the elbow joint of a Siamese cat

Case summary A five-year male neutered Siamese cat presented with intermittent left forelimb lameness with acute deterioration. Diagnosis: Radiographic changes of the forelimb were non-diagnostic. Computed tomography (CT) provided definitive evidence of a medial coronoid process (MCP) fragment. In this specific case, CT imaging revealed pathology that was not clear on standard radiographs. Treatment: The cat underwent elbow arthroscopy using a 1.9-mm scope to inspect the joint and successfully remove the osteochondral fragment. Outcome: Following the arthroscopic debridement, the patient’s lameness resolved within two months of surgery, with no clinical recurrence of lameness reported for up to 4 years post-surgery. Relevance and novel information Fracture of the medial coronoid process is rare in the cat, but CT may be necessary to fully evaluate the elbow joint of lame cats in order not to miss this condition. Resolution of lameness can be achieved by arthroscopic fragment removal.