Multimodal Diagnostic Imaging to Identify Septic Apophysitis of the Proximal Humerus in a Thoroughbred Foal.
Authors: Scilimati Nicola, Pepe Marco, Pressanto Maria Chiara, Angeli Giovanni, Beccati Francesca
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Septic Apophysitis of the Proximal Humerus in a Young Thoroughbred A 4-month-old Thoroughbred filly presented with acute severe forelimb lameness, prompting investigation of the shoulder region using sequential imaging modalities. Radiography demonstrated only subtle changes—mild irregularity and sclerosis at the proximal humeral apophysis—whilst ultrasonography identified moderate synovial effusion in both the intertubercular bursa and scapulohumeral joint, alongside osseous surface irregularity at the intermediate tubercle. Computed tomography proved decisive, revealing a discrete hypoattenuating lesion at the proximal humeral apophysis consistent with septic apophysitis, which enabled ultrasound-guided aspiration for microbial culture and antibiotic sensitivity testing. This case underscores the limitations of conventional radiography in detecting early septic changes in immature bone, particularly in the shoulder region where anatomical complexity can obscure pathology. For practitioners managing acute forelimb lameness in foals, the integration of CT imaging—despite its accessibility constraints—can facilitate rapid aetiological diagnosis and guide targeted antimicrobial therapy, potentially improving outcomes in suspected septic arthropathies where early intervention is critical.
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Practical Takeaways
- •When foals present with acute severe forelimb lameness and imaging findings are inconclusive on radiographs and ultrasound, CT should be considered for definitive diagnosis of septic lesions in the proximal humerus
- •CT imaging can guide targeted sampling from septic foci, allowing culture-directed antibiotic therapy rather than empirical treatment
- •Apophyseal infections in young horses may show subtle radiographic signs initially; advanced imaging should not be delayed if clinical signs are severe
Key Findings
- •CT imaging identified a circular hypoattenuating lesion at the proximal humeral apophysis that was not definitively characterized on radiographs alone
- •Ultrasonography demonstrated moderate synovial fluid accumulation in the intertubercular bursa and scapulohumeral joint with irregular ossifying bone surface
- •CT-guided sampling enabled targeted antibiotic selection based on culture results from the septic focus
- •Multimodal imaging approach (radiography, ultrasonography, CT) was necessary for early and accurate diagnosis of septic apophysitis in this foal