Radiographic imaging of the entheses of the equine thoracic foot

Background An injury of a tendon or ligament of the equine foot is frequently a cause of lameness. The optimal radiographic projections delineating the entheses of five commonly injured tendons and ligaments of the foot should be described. Methods The entheses of the collateral ligaments of the distal interphalangeal joint, the collateral sesamoidean ligaments of the navicular bone, the deep digital flexor tendon, the common digital extensor tendon and the distal sesamoidean impar ligament were isolated from a thoracic foot of three cadavers. Three standard radiographic projections (60‐degree, dorsoproximal‒palmarodistal oblique [D60°PrPaDO] projection, lateromedial [LM] projection and dorsopalmar [DP] projection) were obtained of each foot, with the entheses of the selected tendons and ligaments identified with a marker. Results The entheses of all structures analysed in this study were best identified on the D60°PrPaDO and LM projections. The insertion of the collateral ligaments of the distal interphalangeal joint was also easily identified on the DP projection. Limitations A limitation was the inability to distinguish between lateral and medial sides of the feet. Conclusions The radiographic images of the foot created in this study can serve as a guide for identifying enthesopathies of the ligaments and tendons of the equine foot.