Fig. 1

Preoperative measurements were performed using X-ray and CT scans. A We stuck a 100 mm-long marker rod with metal balls on both sides on the outside of the thigh, and took an X-ray of the femur. Measuring the diameter of the medullary cavity at the narrowest part of femoral diameter on X-ray film and calculating the actual diameter of the femoral medullary cavity can avoid the error caused by X-ray magnification and provide the basis for the types of femoral prosthesis that may be used during operation. Photos with marker posts were added. B Preoperative CT scanning of the hip joint was performed to evaluate the position and diameter of the true acetabulum and to guide the selection of acetabular prosthesis size and reconstruction of the true acetabulum