Related Experiment Video
Updated: Dec 17, 2025
09:51
The Transition to an Anterior-Based Muscle Sparing Approach Improves Early Postoperative Function but is Associated with a Learning Curve
Published on: September 7, 2022
3.4K
Pelvic rotation after total hip arthroplasty is dynamic and variable.
Gregory S Kazarian1, Derek T Schloemann1, Toby N Barrack1
1Department of Orthopaedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri, USA.
The Bone & Joint Journal
|July 1, 2020
Summary
Pelvic sagittal alignment changes after total hip arthroplasty (THA), persisting one year post-surgery. These dynamic pelvic shifts significantly alter acetabular component orientation, impacting surgical outcomes.
Area of Science:
- Orthopedic Surgery
- Biomechanical Engineering
- Radiology
Background:
- Acetabular component positioning is critical for total hip arthroplasty (THA) success.
- Pelvic sagittal alignment can influence component orientation, but its dynamic changes post-THA are not fully understood.
Purpose of the Study:
- To evaluate changes in pelvic sagittal alignment one year after THA.
- To determine the impact of these alignment changes on acetabular component position.
Main Methods:
- One-year follow-up of 50 patients from a previous THA study.
- Radiological assessment of pelvic ratio using anteroposterior pelvic radiographs in the standing position (preoperative and one-year postoperative).
- Pelvic ratio defined as the ratio of vertical distance (inferior SI joints to superior pubic symphysis) to horizontal distance (inferior SI joints).
Main Results:
- Pelvic ratio decreased (posterior tilt) in 54% of patients, increased (anterior tilt) in 12%, and remained stable in 34% at one year.
- These pelvic tilt changes correlated with potential acetabular component abduction errors (5°-10° in 22%, >10° in 6%) and version errors (5°-10° in 22%, >10° in 44%).
Conclusions:
- Pelvic sagittal alignment is dynamic and variable one year after THA.
- These persistent changes in pelvic orientation alter acetabular component version and inclination.
- Surgeons should consider postoperative pelvic rotation when planning acetabular component placement.
