Bone lesions in pigs with locomotor dysfunction of hind legs

A study was made of the femur, sternum and rib of 10 male Yorkshire x Landrace pigs weighing 87 to 179 kg at 9 months. Locomotor dysfunction of the hind legs occurred in all animals from 5 to 9 months of age. Noteworthy gross changes were a markedly open angle between the long axis of the femoral head and that of the great trochanter, and an abnormally high position of the top of the great trochanter in relation to the level of the femoral head. Histological changes in the femoral growth plate were characterized by oblique arrangement of chondrocytic columns, necrosis of the cartilage in the area adjacent to the metaphysis or epiphysis, eosinophilic streaks, and loosening of the cartilage matrix. Cracks with fractures of the cortex, and eosinophilic streaks and loosening of the cartilage matrix were observed in the growth plate of the sternum. Oblique arrangement of chondrocytic columns, eosinophilic streaks and loosening of the cartilage matrix were found in the growth of the rib.