Hypothesis 3

The bull calf may have had a congenital valgus deformity, due to dysmaturity (or immaturity - parturition triggered early because of large size).  The bones of the carpus were incompletely ossified.  This congenital malformation was exacerbated by trauma during delivery, which resulted in a metacarpal bone fracture.  Bandaging for the fracture led to abnormal weight bearing forces on the carpal bones during ossification, leading to abnormal ossification and valgus deformity. 

The superficial wounds on the skin look  very much like they resulted from pressure necrosis.  The excessive pressure that caused those lesions would also have compromised blood flow to the area, increasing the potential for septic infection.  Systemic sepsis may have resulted with secondary septic infection of the joint.  We have evidence of a septic process going on in the area because of the purulent discharge and draining tracts.  The elevated TPR are supportive of sepsis. 

The fibrotic bands, helping to pull the foot into an abnormal position, are most likely extensor tendons that have have contracted due to lack of weight bearing.  Local inflammation would lead to fibrin deposition, producing adhesions between the tendons and tissues on dorsum of the foot.