The influence of surgical approach on postoperative pelvic tilt after total hip arthroplasty

Background Past reports have shown the tendency of posterior pelvic tilt to increase over time after total hip arthroplasty (THA). We have hypothesized that the volume and extent of released joint capsule may influence the change in postoperative pelvic tilt. This study was conducted to ascertain whether surgical approach during THA (posterior or anterior) has an effect on postoperative changes in pelvic tilt. Methods We conducted a retrospective review of 81 hips in 60 patients. Patients classified as Crowe group 2, 3, and 4, those who had multiple previous compression fractures, and those with spinal fusion due to spinal arthrosis were excluded. Also, those who had previously undergone THA or total hip resurfacing also were excluded. Patients were divided into two groups, those with preoperative anterior pelvic tilt and those with posterior tilt. Preoperative and postoperative X-rays and CT scans for each group were assessed to determine the chronological change in pelvic tilt, and the data were statistically analyzed for patients who had experienced both the posterior and anterior approaches. Results Regardless of surgical approach, there was no significant difference in the mean change in postoperative APP angle over time in either the bilateral or unilateral cases or in the groups of preoperative anterior or posterior pelvic tilt. Conclusions Our results showed that surgical approach does not influence postoperative pelvic tilt after THA. In preoperative planning for THA, therefore, surgeons may need not to consider the difference of surgical approach with regard to postoperative changes in pelvic tilt.