It was reported by Salter, R. B. that the extent of the subchondral fracture in the early stage in Perthes' disease correlated precisely with the subsequent extent of maximum resorption in the femoral head. In this study, we examined wheather the sign of subchondral fracture on the X ray films can be reliable for the decision of the prognosis and the choice of the treatment in the early stage of this disease.
Total number of the patient we studied was 240 cases of 265 hips. The signs of subchondral fracture was seen in 65 hips. The degree of subchondral fracture was proportional well to the grade by Catterall's classification.
