Necrosis of the joint cartilage (Waldenström disease) of the right hip after cast period. The functional value of mobility of the affected hip was reached. Reversible clinical range of motion and deformation of both the femoral head and acetabulum were detected. (A and B)-Anteroposterior and frog-leg lateral radiographs of the pelvis made before treatment, showing bilateral chronic SCFE, being moderate slip in the right hip and mild in the left. (C) Anteroposterior roentgenogram of both hips after cast treatment with bilateral leg casts in abduction and an internal rotation. We may observe narrowing and irregularity of the right hip joint with demineralization of the surrounding bone = chondrolysis of the right hip. (D and E) Anteroposterior and frog-leg lateral radiographs of the hips showing closure of the growth-plate in the right hip, further demineralization with obliteration of the joint space and irregularity of the head of the femur and acetabulum and also decrease in cartilage thickness. (F and G) Anteroposterior and frog-leg lateral radiographs observing in the right hip some restoration of cartilage, with irregular contour of the femoral head. (H and I) Anteroposterior and frog-leg lateral radiographs observing in the right hip joint, the articular space is now widened compared to the initials X-rays. The femoral head presents mild deformity and limited range-of-motion in the right hip.