Diagnosis

    The calf has a non-union of a previous closed simple oblique diaphyseal fracture of the left forelimb.  Radiographs of the affected limb showed bony proliferation along both sides of the fracture sight that extended proximally and distally and increased cortical radiodensity.  This is indicative of a viable/biologically active nonunion fracture that is hypertrophic/elephant foot callus.  The hypertrophy is a result of a bridging callus that has not ossified due to motion at the fracture sight from improper immobilization/casting.  The fracture is viable and has a proliferative bone reaction with cartilage and fibrous tissue that has been unable to ossify.  It is highly unlikely that the trauma to the leg resulted in any vascular damage as the fracture sight is showing viable/reactive bony proliferation.  This is a good prognostic indicator for union upon resetting the fracture.  The swelling of the limb is due top both the inflammatory response to the bacterial infection as well as the bony proliferation.

    The patient also has cutaneous draining lesions that are infected with E. coli and Staph aureus that has likely extended to the bone and contributed to the delayed union in this case.  Although bone remodeling and healing can take place in an inflammatory environment, it will be significantly delayed.  The calf's hematologic and urinalysis parameters were unremarkable.