TITLE:
Compression Test and Finite Element Analysis for Failure Criterion of the Tibial Post of a Posterior-Stabilized Knee Prosthesis
AUTHORS:
Rina Sakai, Urabe Ken, Kazuhiro Yoshida, Kiyoshi Mabuchi, Masanobu Ujihira
KEYWORDS:
Proximal Humeral Fracture, Retrograde Intramedullary Nailing, Anterograde Intramedullary Nailing, Locking Plate, Internal Fixation
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.12 No.5,
May
21,
2019
ABSTRACT: Post cam mechanism of Posterior Stabilized (PS) knee prostheses is useful to realize intrinsic stability for cases with severe degeneration. However, some retrieval studies report severe failure of the polyethylene tibial post. We thought that severe failures were caused by high loads during daily activities. In the current study, we performed a compression test and a finite element analysis of the mechanical forces produced in the tibial post in posterior-stabilized knee prostheses in order to develop a specification for the tibial posts found in the polyethylene inserts of PS knee prostheses. Anterior tibial post impingement and posterior tibial post impingement were simulated. The surface pressure values detected in the compression test were consistent with those obtained in the FE analysis. Of the three designs, the lowest von Mises stress values were generated inside the round tibial post; therefore, tibial posts should be round. The risk of tibial post failure was low when 500 or 1000 N was loaded onto the knee joint. It was suggested that tibial post failure occurs when the shear strain at the base of the tibial post exceeds 0.1.