Fig. 4

Periprosthetic distal femur fracture in case number 11 treated with a circular external fixator. (A) Preoperative antero-posterior X-ray. (B) Preoperative lateral angle X-ray. (C) Preoperative coronal CT scan. (D) Preoperative sagittal CT scan. (E) Preoperative medial-lateral angle 3D CT. (F) Preoperative posterior-anterior 3D CT. (G) Preoperative lateral-medial angle 3D CT. (H, I) Immediate postoperative X-ray. (J) Antero-posterior X-ray 2 weeks after removal of the tibial ring. (K) Lateral angle X-ray 2 weeks after removal of the tibial ring. (L,M) X-ray after circular external fixator removal and weight-bearing, postoperative 12 weeks. (N,O) CT after circular external fixator removal and weight-bearing, postoperative 12 weeks. CT, computed tomography; 3D, three-dimensional