Automated Femoral Stem Canal Fill Ratio Evaluation for Bipolar Hip Arthroplasty in 2D X-Ray Image

Abstract

A stem loosening is one of the significant problem in the bipolar hip arthroplasty (BHA), causes a pain and instability of a patient’s hip, and requires a further surgery of BHA. A stem canal fill ratio (SCFR), a general evaluation of the stem loosening, have been clinically studied many; however, a determination of the optimal SCFR evaluation has not been still understood well. A purpose of this study is to propose an automatic and quantitative evaluation of SCFR from BHA hip X-ray image. A proposed method segmented the femoral canal and stem, and evaluated SCFR. In experiments, a proposed method’s accuracy was validated, and six BHA patients’ SCFRs were clinically evaluated (age 88±7 (74–93), one male / five females). In result of the proposed method’s accuracy, the femur canal was 90.60±3.65%, and the stem was 97.83±0.46%; therefore, the proposed method had the accuracy to well evaluate SCFR. Result of six BHA patients’ SCFRs was 63.70±5.62%. In conclusion, the proposed method was able to automatically evaluate SCFR from the hip X-ray image with BHA.