Longitudinal evaluation of time related femoral neck narrowing after metal-on-metal hip resurfacing

Figure 1 Radiograph showing measurement of Femoral Neck and Prosthesis. A: Neck-to-prosthesis ratio was calculated by dividing the femoral neck diameter at the prosthesis; B: Neck-to-prosthesis ratio was calculated by the diameter of the prosthesis at the opening edge.

Figure 2 Inter-rater reliability comparison graph of paired femoral neck measurements.

Figure 3 Inter-rater reliability graph of paired prosthesis measurements.

Figure 4 Neck-prosthesis ratio at follow-up (a) indicates significant change in neck-to-prosthesis ratio from immediate postoperative to 3 mo postoperatively.

Figure 5 Femoral neck narrowing after Birmingham metal-on-metal hip resurfacing prosthesis occurs as early as 3 mo postoperatively and the neck-to-prosthesis ratio stabilizes thereafter. A: Immediate postoperative X-ray; B: Cirle showing neck narrowing at 3 mo postoperatively.