Long incomplete fractures originate from the mid-sagittal groove of the proximal phalanx and extend into the small intramedullary canal, just distal to the middle of the proximal phalanx.
Those fractures are most typically seen in racing breeds.
This fracture may be represented as a simple sagittal configuration (left image) or may propagate medially or laterally in the mid-proximal phalanx (right image).
Clinical signs are usually acute severe lameness with or without an effusion of the fetlock joint.
In most cases, a dorsopalmar radiograph confirms the diagnosis. A complete radiographic series is required to properly evaluate the full extent of the fracture and to rule out additional injury.