A 27-year-old male patient consulted a doctor about pain in the lower third of the thigh with weight bearing activities and unloaded. Two years ago, the patient underwent treatment in the casualty depatment for the open fracture of the lower third of femur. The fracture healed slowly, the healing process was accompanied by prulent inflammation. Objectively: edema of the lower third of the thigh, elevated local temperature. Radiograph shows signs of destruction and sequestration. What is the most likely diagnosis?