Perthes' disease, or osteochondritis juvenilis of the hip, results in far more extensive bone atrophy than has been supposed. The bone atrophy and rarefication are so extensive that they have changed our previous conception of the pathology of the disease.
Up to the present time, the only joint and bone changes recognized in Perthes' disease have been a partial or total destruction of the head of the femur with a stumping of the neck, together with a thinning of the femoral shaft. Most authors have agreed with the unsustained suggestion, made by Freiberg1 at the last session of this Association, that the disease is caused by tonsillitis or some other local infection. Experiments have been made on animals by Allison2 to determine what influence a slight injury or displacement to the epiphysis might have on the hip, and his results were negative.
Since I desired to make a comparative study
BLANCHARD W. TREATED AND UNTREATED OSTEOCHONDRITIS JUVENILIS OF THE HIP. JAMA. 1917;LXIX(13):1060-1064. doi:10.1001/jama.1917.02590400020007