The femoral heads of twenty-four weaned mongrel puppies were surgically infarcted. Two specimens were not available for study. The remaining twenty-two specimens were labeled in vitro with 35S for autoradiography and were examined histologically after staining with hematoxylin and eosin and toluidine blue.
Of the twenty-two femoral heads studied, seventeen displayed no deformation at post mortem; two, slight flattening; one, severe deformation; and two, moderately severe deformation. The present paper reports the findings in the first nineteen femoral heads.
In eight infarcted femoral heads, the chondrocytes displayed no abnormality: a fact which demonstrates that such chondrocytes can survive when nourished by the synovial route alone. The cartilage in the remaining eleven infarcted femoral heads was abnormal.
Fatigue fractures in the ossific nucleus were associated with these cartilaginous abnormalities in specimens examined more than twenty-one days after infarction.
The significance of these findings in the pathogenesis of Perthes disease in man is discussed.