Purpose: This study examined intraoperative imaging to monitor the alignment of the acetabular cup for total hip replacement arthroplasty (THRA) using C-arm fluoroscopy and to increase the accuracy of THRA prosthetic fixation.
Materials and Methods: From March 2004 to April 2007, 54 patients underwent THRA monitored by the imaging. 40° inclination and a 15° anteversion angle was considered to be ideal. The items compared included the alignment of the acetabular cup and the follow up rates of the hip dislocation.
Results: There was one case of hip dislocation. The mean inclination angle of the acetabular component was 39.9° with a standard deviation of 3.038. The mean anteversion angle of the acetabular component was 14.9° with a standard deviation of 1.398. The mean difference examination and variance in the anteversion angle showed a significant result . (P<0.05)
Conclusion: Intraoperative imaging increases the alignment accuracy of the acetabular cup and helps stabilize the prosthesis.

Keywords: Total hip replacement arthroplasty, Acetabular cup, Alignment