Verifying a Software System for Designing Custom Hip Stems Based on X-Ray Films

If a custom hip stem could be designed according to X-ray films, the cost of the hip stem would be reduced, and a simpler designing method could be provided than using computer tomography images. In addition, the problem, which is that hip stems cannot be designed for some revision operations because of metal artifacts in computer tomography images, could be solved. A software system for designing custom hip stems based on X-ray films was developed. In order to verify whether the software system could be used, eleven femurs were used for this study. Hip stems for these eleven femurs were designed by using the software system. Ten of these femurs were taken computer tomography scans directly. According to the data collected from the computer tomography images, models of these ten femurs were rebuilt. Ten hip stem models, designed for these ten femurs, were simulated to be inserted into corresponding femur models. Results show each of the ten hip stems matches its corresponding femur. The hip stem designed for the remaining femur was manufactured and inserted in the remaining femur. Cancellous bone, retained in the matching area, was about 1–1.5 mm thick. From the above verifications, it could be concluded that the software system for designing custom hip stems based on X-ray films could be used to design custom hip stems.