The construction of canine distal limb models used in teaching sonography identification of vegetal foreign bodies

Musculoskeletal ultrasonography is a useful tool to identify radiolucent vegetal foreign bodies (VFBs). However, limited ultrasound experience and unfamiliarity with the normal sonographic appearance of anatomical structures can decrease clinician confidence. This study aimed to design a reusable silicone model that can teach VFB identification within the canine distal limb. Four canine hindlimbs were used to design the silicone models, and 12 canine distal forelimbs were constructed. The model was constructed using cadaver bones, barley grass (Avena fatua) seeds, and silicone to mimic the anatomy of the canine distal limb with a grass seed VFB. Limbs were randomly grouped based on grass seed locations: (1) the interdigital webbing, (2) the palmar surface of the canine forelimb immediately proximal to the metacarpal pad, (3) the dorsal surface of the distal limb immediately proximal to the proximal phalange, or (4) no grass seed (control) placed. Each limb was systematically ultrasounded and compared with cadaver limbs and clinical VFB cases. A comparison of ultrasonographic images validated the construction, revealing that the simulation model replicates the anatomical and echotexture characteristics of the normal canine distal limb. Furthermore, these models also have a likeness to clinical canine distal limb VFB cases and can be utilized as a training tool.