Related Experiment Video
Updated: Jun 20, 2026
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
Total hip arthroplasty in acetabular protrusio
1University of California-San Francisco, 500 Parnassus Avenue, San Francisco, CA 94143, USA.
Insights
Total hip arthroplasty (THA) effectively reconstructs acetabular protrusio defects using cementless components and bone grafting. Reconstruction cages offer an alternative for inadequate acetabular rim support, ensuring favorable outcomes.
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
Background:
- Protrusio acetabuli involves a central acetabular defect with medial femoral head migration.
- This condition can arise from metabolic or mechanical bone issues affecting the periacetabular region.
Purpose of the Study:
- To outline surgical reconstruction strategies for acetabular protrusio during total hip arthroplasty (THA).
- To evaluate treatment options based on acetabular rim integrity and bone quality.
Main Methods:
- Utilizing cementless, porous-coated acetabular components lateralized on the intact acetabular rim.
- Employing morsellized autograft to fill the central cavitary defect.
- Considering reconstruction cages for cases with inadequate rim support due to bone loss or osteoporosis.
Main Results:
- Cementless components on a supported rim with grafting demonstrate favorable outcomes.
- Reconstruction cages provide necessary pelvic fixation when rim support is compromised.
- Preoperative templating is crucial for managing offset and leg length discrepancies.
Conclusions:
- THA for acetabular protrusio can achieve success rates comparable to conventional THA.
- Surgical approach selection depends on the mechanical integrity of the acetabular rim.
- Bone grafting and appropriate implant choice are key to successful reconstruction.
Abstract:
Protrusio is a central acetabular defect resulting from migration of the femoral head medial to Kohler's line. Protrusio can develop in association with a number of conditions that affect the metabolism or mechanical behavior of the periacetabular bone. Total hip arthroplasty (THA) for acetabular protrusio requires reconstruction of the contained cavitary defect. The acetabular rim is generally intact. The defect can be effectively treated with a lateralized cementless porous-coated component supported on the peripheral acetabular bony rim. Morsellized autograft is used to fill the medial defect. However, if the rim is inadequate to provide mechanical support for a cementless cup due to bone loss or osteoporosis, cementless cup reconstruction can result in medial migration. If rim support is inadequate, a reconstruction cage is a more appropriate option to gain fixation to the pelvis above and below the acetabulum. Total hip arthroplasty for protrusio can also affect both offset and leg length, so careful preoperative templating is important to help determine implant position. Results of THA with medial acetabular bone grafting for protrusio acetabuli have been favorable, with success rates similar to conventional THA.