Investigation of mechanical behavior on the cement hip spacer geometry under finite element method and compression load test

Eakkachai Warinsiriruk; Nutchanat Thongchuea; Nachapan Pengrung; Chavarat Jarungvittayakon; Paphon Sa-Ngasoongsong; Kulapat Chulsomlee

doi:10.1016/j.jor.2023.10.025

Investigation of mechanical behavior on the cement hip spacer geometry under finite element method and compression load test

J Orthop. 2023 Nov 7:47:115-121. doi: 10.1016/j.jor.2023.10.025. eCollection 2024 Jan.

Authors

Eakkachai Warinsiriruk¹, Nutchanat Thongchuea¹, Nachapan Pengrung², Chavarat Jarungvittayakon², Paphon Sa-Ngasoongsong², Kulapat Chulsomlee³

Affiliations

¹ Department of Industrial Engineering, Faculty of Engineering, Mahidol University, Thailand.
² Department of Orthopedics, Ramathibodi Hospital, Mahidol University, Thailand.
³ Ramathibodi Medical School, Chakrinaruebodindra Medical Institute, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Thailand.

PMID: 38046455
PMCID: PMC10687331 (available on 2025-01-01)
DOI: 10.1016/j.jor.2023.10.025

Abstract

Background and objective: Antibiotic cement spacers (CS) are standard treatment for periprosthetic hip infection. However, complications such as cement spacer fracture and spacer dislocation remain common after surgery. The aim of this study is to investigate the influence of CS geometry design on mechanical strength through finite element analysis and compression load testing.

Methods: The CS model was generated using the three-dimensional engineering program, and an aluminum molding block was created. The mechanical behavior was analyzed using finite element method (static structural version 2022R1). A compression load test was employed to evaluate both fatigue failure and the ultimate failure load.

Results: The femoral neck area experiences the highest Von Mises stress (36.32 MPa) with lowest safety factor (1.37). The femoral head shows the most significant deformation. The designed CS is capable of withstanding repetitive loads of 35-50 kg for a total 600,000 cycles. The ultimate load to failure was 4354 N. The fracture analysis reveals a vertical sharing type at the femora neck and transverse-short oblique type at the proximal stem.

Conclusion: The designed CS can withstand the majority of daily activities with 50 % partial weight bearing for patients weighing 70-100 kg. The femoral neck area experiences the highest stress and shear strain. To optimize the geometric design of the CS, the increase in femoral neck-shaft angle and maximizing the femoral neck diameter should be consider.

Keywords: Bone cement; Cement spacer; Compression load test; Equivalent strain; Finite element; Hip replacement; Periprosthetic joint infection; Von mises stress.

Publication types

Review