Comparative Analysis of the Biomechanical Behavior of Collar and Collarless Stems: Experimental Testing and Finite Element Modelling

Autor: Jucélio Tomás Pereira, Ievgen Levadnyi, Yaodong Gu, Alexander Loskutov, José Eduardo Gubaua, Jan Awrejcewicz, Gabriela Wessling Oening Dicati
Rok vydání: 2021
Předmět:
Zdroj: Journal of Medical and Biological Engineering. 41:844-855
ISSN: 2199-4757
1609-0985
DOI: 10.1007/s40846-021-00652-w
Popis: During total hip replacement (THR), prosthesis material is stiffer than the bone tissue, decreasing load transmission to the host tissue around the prosthesis. After a THR, the aim is to achieve stress distribution along the femur close to normal physiological stress distribution for all loads transferred across the hip joint. In this study, we analyzed the advantages of using a collared stem over collarless one with the finite element method (FEM), strain gauges (SGs), and the digital image correlation (DIC) system. In the biomechanical tests, we implanted composite femurs and loaded them with the stance configuration in a universal testing machine (Instron). We compared the predicted strains with the strains recorded experimentally in the same regions of the femur. The results revealed that for collarless stems, a high level of stress concentration is observed in the distal region of the implant but not in the proximal region. The collared case presents a strain distribution closer to that of a healthy bone proximal zone that was almost two times better than in case of the collarless stem, whereas stresses in the distal part of the femur corresponded to a healthy state. Finally, the numerical results for the bone adaptation around the implant provided clear evidence that the collar design strongly influences the proximal resorption because of better load transmission. According to both the numerical and experimental results, a collar that connects to the bone cut may decrease the proximal stress shielding effect and distal cortical hypertrophy.
Databáze: OpenAIRE
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