Fig. 2.

The therapeutic process of the first typical case. A, B The initial X-ray displayed the patient suffered the distal femoral displaced fracture; C–E The patient underwent the surgical treatment, and at 13 months after the initial surgery, X-ray and CT scan showed fracture nonunion and ends sclerosis, meanwhile, the plate had broken; F we cleared the sequestrums and filled a PMMA spacer into the femoral defect with 9.5 cm length, and stabilized the femur by external fixator; G–J after a 10-week interval, the bone defect was repaired by a customized 3D printed scaffold, and the postoperative regular X-rays showed the scaffold kept stable and new bone grew gradually on the surface of scaffold from both ends of the defect (as displayed in the red boxes)