Radiographic anatomy of the equine distal tibia

Area of Science:

• Veterinary Radiology
• Equine Anatomy
• Diagnostic Imaging

Background:

• The radiographic anatomy of the equine distal tibia presents challenges due to complex osseous structures.
• Superimposition and similarity between these structures hinder accurate localization of pathology in equine tarsus radiographs.

Purpose of the Study:

• To provide a detailed description of the normal radiographic anatomy of the equine distal tibia.
• To identify challenges in visualizing specific structures on routine radiographic projections.
• To propose an improved radiographic projection for better anatomical detail.

Main Methods:

• Prospective, descriptive, anatomical study utilizing three equine cadaveric limbs.
• Radiographic identification of osseous protuberances using radiopaque markers.
• Evaluation of multiplanar and 3D computed tomography (CT) reconstructions to create anatomical maps.

Main Results:

• The lateral malleolus has cranial and caudal protuberances often superimposed on standard views, obscuring the cranial part.
• The medial malleolus, while having discrete margins, can be ill-defined on certain oblique views due to superimposition with the talus.
• The intermediate cochlear ridge's cranial protuberance is superimposed with the calcaneus and talus on dorsoplantar views.

Conclusions:

• The complex anatomy of the equine distal tibia necessitates a detailed anatomical reference for accurate radiographic interpretation.
• A novel plantaro 15° distal 85° lateral-dorsoproximomedial oblique projection is proposed to effectively isolate all distal tibial protuberances.