Radiological interpretation of the navicular bone

Acquisition of a sufficient number of high quality radiographic views is an essential prerequisite to accurate radiological interpretation of the navicular bone. This requires appropriate preparation of the foot, careful attention to limb position and to both centring and direction of the x‐ray beam, according to hoof capsule conformation. Artefacts are easily created. Potentially significant radiological abnormalities include: entheseiophytes at the proximomedial and proximolateral aspect of the bone; proximal or distal extension of the flexor border of the bone, distal border fragments, 8 or more large and variably shaped distal border radiolucent zones; discrete radiolucent areas in the spongiosa with or without detectable communication with the flexor cortex; new bone at the sagittal ridge; increased thickness of the flexor cortex; sclerosis of the spongiosa; and a bipartite bone.