Effect of segmental rim defect morphology on press-fit stability of the cementless acetabular cup - a finite element analysis

Sep 28, 2026

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Segmental rim defect (SRD) of the acetabulum is a common consequence after primary total hip arthroplasty, and its morphology influences surgical reconstruction decisions. This study quantifies how SRD geometric features and locations affect the press-fit stability of cementless acetabular cups. A 3D finite element model based on CT-derived hemipelvic bone was built with varying SRD submodels and evaluated using push-out and lever-out tests via quasi-static non-linear analysis, including interfacial micromotion comparisons during gait.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Methods

Results

Conclusion

TYPE Original Research PUBLISHED 10 December 2025 DOI 10.3389/fmed.2025.1729549 OPEN ACCESS EDITED BY Jun Li, Second Hospital of Anhui Medical University, China REVIEWED BY Dongliang Zhao, Shenzhen Bay Laboratory, China Yuping Deng, Southern Medical University, China *CORRESPONDENCE Huan Zhong [nq6584@163.com](nq6584@163.com)[ ](nq6584@163.com)Hanbin Ouyang [robin85@163.com](robin85@163.com) †These authors have contributed equally to this work RECEIVED 21 October 2025 REVISED 16 November 2025 ACCEPTED 19 November 2025 PUBLISHED 10 December 2025 CITATION Zhang X, Lin K, Feng B, Chen H, Zhong Hand Ouyang H (2025) Effect of segmental rim defect morphology on press-ﬁt stability of the cementless acetabular cup: a ﬁnite element analysis. Front. Med. 12:1729549 . doi: 10.3389/fmed.2025.1729549 COPYRIGHT © 2025 Zhang, Lin, Feng, Chen, Zhong and Ouyang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Effect of segmental rim defect morphology on press-ﬁt stability of the cementless acetabular cup: a ﬁnite element analysis Xin Zhang1,2†, Kewei Lin1†, Bolin Feng1 , Haicong Chen1 , Huan Zhong1* and Hanbin Ouyang1* 1 Department of Orthopedic Center, Joint Surgery, The Afﬁliated Hospital of Guangdong Medical University, Zhanjiang, China, 2 Department of Orthopaedic Trauma, Heze Municipal Hospital, Heze, China Introduction: Segmental rim defect (SRD) of the acetabulum is a common type of osteolysis following primary total hip arthroplasty. Accurate quantitative evaluation of severity and morphology of the SRD can provide critical information to surgeons for decision-making on surgical reconstruction. Therefore, we aim to investigate the effect of morphologic features of SRDs on the press-ﬁt stability of cementless cups. Methods: A 3D ﬁnite element model of Sawbones hemipelvic bone was developed using CT scan. Submodels with varying SRD geometries and locations were created, followed by Boolean reaming and virtual 1-mm press-ﬁtimplantation of a cementless cup. The press-ﬁt stability was evaluated by using the push-out and lever-out tests based on quasi-static non-linear ﬁnite element analysis. The peak micromotion (PM) levels of all submodels at the bone-cup interface during the gait cycle were also compared. Results: Despite the depth and width, the defect in the weight-bearing zone exhibited the lowest average push-out load of 2429 􀀆 294. 19 N and lever-out moment of 100 􀀆 8.40 Nm comparing to those in other zones. The maximal push-out and lever-out loads of the cup decreased as either the width or depth of defect increased. The percentages of strength reduction for push-out and lever-out tests, respectively up to 47.8 and 34.1%, were signiﬁcantly higher in the weight-bearing zone comparing to those in the other zones. During the gait cycle, all worst-scenario defects resulted in varying levels of increase in interfacial PM comparing to the intact acetabular rim. In the second half of the gait cycle, the defect in the weight-bearing zone produced the highest level of PM. Conclusion: In revision total hip arthroplasty (r-THA), a large SRD in the weightbearing zone can result in the utmost loss of press-ﬁt stability and a detrimental interfacial micromotion, which may lead to early loosening of the cup. Thus, an accurate quantitative evaluation of defect morphology is valuable for surgeons to develop a reﬁned plan for reconstruction of initial stability of a cementless cup. KEYWORDS bone defect, acetabulum, total hip arthroplasty, ﬁnite element analysis, press-ﬁt Frontiers in Medic

FAQs

What was the study aiming to determine about SRDs and cementless cups?

The study investigated how morphologic features of segmental rim defects affect the press-fit stability of cementless acetabular cups, including changes in stability measures and interfacial micromotion.

How were the finite element models and SRD scenarios constructed?

A 3D finite element model of Sawbones hemipelvic bone was developed using CT scans, and submodels with varying SRD geometries and locations were created for virtual reaming and 1-mm press-fit cup implantation.

What were the main findings regarding the weight-bearing zone defects?

Defects in the weight-bearing zone showed the lowest average push-out load and lever-out moment, larger strength reductions than other zones, and the highest interfacial micromotion in the second half of the gait cycle for worst scenarios.

Sep 28, 2026

Uploaded by Rizky