ABSTRACT
Objective
To investigate whether the anteversion angle of acetabular prosthesis can be evaluated on the antero-posterior X ray film of common double hip joint．
Methods
Total 32 patients （ 41 hips ） after total hip arthroplasty were selected ， including 18 males and 14 females ， aged （ 66．2±4．1 ） years． All patients completed the positive X ray film of both hips and plain CT scan of pelvis after operation． Acetabular anteversion was measured by plain CT scan of pelvis ， and measured by Saka and other measurement formulas on X ray film．
Results
The acetabular anteversion measured by X ray film was （ 16．2±5．0 ） °and that measured by CT was （ 31．8±9．7 ） °（P＝0．00 ） ． In addition ， there was a significant linear correlation between X ray film and CT （ Pearson correlation coefficient （ r＝0．84 ， P＝0．00 ） ．
Conclusion
CT can accurately measure the acetabular anteversion ， but it has obvious disadvantages ， such as large radiation ， high cost ， phantom CT artifact and so on． Although Saka measurement formula can not directly obtain the accurate acetabular anteversion as CT measurement ， it has a high correlation with the acetabular antever- sion measured by CT． Therefore ， the method proposed in this study can also preliminarily evaluate the acetabular anteversion．
