Diagnosis

        Our diagnosis is hypertrophic viable delayed union.  We 
classified it as delayed because we think the fracture occurred three 
months ago when the calf was pulled during parturition.  Furthermore, 
after bandaging and casting there is radiographic evidence of a 
persistent fracture gap.  We also had draining tracts because the 
fracture site has been infected by Staphlococcus and E. coli.  The 
gap has not closed due to improper reduction.  The fracture pieces 
are not held in proper opposition because of the large size of the 
calf.   Moreover, the calf was also not on stall rest which could 
have further destabilized union.  The fracture is in the process of 
repairing itself.  This is evidenced by formation of the callous 
which occurred due to good vascular supply to the fracture site. 
Initially the callous began as fibroblast and fibrous tissue which 
were replaced by dystrophic calcified tissue.  The calcified tissue 
is now being replaced by bone through the process of creeping 
substitution.  This is a slow process that results in a delayed 
union.  If given adequate time the fracture ends should meet.  There 
is also a metacarpal/phalangeal valgus deformity.  This was probably 
due to pathological compression from poor bandaging/casting technique 
after the original insult.
        There is also a local infection of Staphlococcus and E. coli. 
This is evidenced by purulent draining tracts and inflammation of the 
surrounding soft tissue.