Epiphysiodesis and subtrochanteric osteotomy have long been recognized as valuable procedures in the treatment of the patient with a moderately or markedly displaced femoral capital epiphysis. Typically these have been performed individually or sequentially. The operation herein described combines the two in one single-stage procedure. Using a stainless steel Lorenzo Screw, the epiphyseal plate is transfixed and further capital displacement prevented. The subtrochanteric compensatory osteotomy is performed using simple visual clinical guidelines and is held rigidly immobilized with a variable angle sideplate affixed to the Lorenzo Screw. The firm fixation enables one to dispense with plaster immobilization and begin the patient on an early exercise program. Restoration of a more normal range of motion, especially regarding rotation internally, abduction, and flexion is easily obtained. Radiographic correction of varus and posterior tilting are thereby secured.