Purpose: It is important to clarify the link between acetabular dysplasia and pelvic tilt to optimize surgical planning and postoperative outcomes. We sought to investigate functional pelvic tilt in patients undergoing total hip arthroplasty with acetabular dysplasia.
Materials & Methods: From 2014 to 2020, pre-operative AP Pelvis X-rays, CT scans, and other patient-specific data such as pelvic tilt, lumbar lordotic angle, etc were collected as part of surgical planning for total hip arthroplasty. From this database, we investigated 678 female patients under the age of 50 that had undergone preoperative standing AP pelvis X-rays. Analysis was performed by investigating how many patients whose hips are dysplastic displayed anterior pelvic tilt. Anterior pelvic tilt was defined in three different positions, sitting/supine/standing. Correlation between the severity of the dysplasia and anterior pelvic tilt was also investigated.
Results: Out of the 678 patients, 80.7% had a dysplastic hip. 70.7% displayed an anterior standing pelvic tilt, 89.2% displayed an anterior supine pelvic tilt, and 98.3% displayed a seated anterior pelvic tilt. An observed 81.3% of the patients who have an anterior pelvic tilt have a unilaterally or a bilaterally dysplastic hip. Out of the anterior pelvic tilt group, 63.9% were bilaterally dysplastic hip patients.
Conclusion: The majority of the pre-operative patients displayed an anterior pelvic tilt in all 3 positions (standing, supine, seated). Unilaterally or bilaterally dysplastic patients were also more likely to display an anterior pelvic tilt. Within the dysplastic group, bilateral patients were more likely to display anterior pelvic tilt
