Failure Analysis of PCA Revision Total Knee Replacement Tibial Component: A Preliminary Study Using the Finite Element Method

Abstract

This report documents the results of a finite element method (FEM) "worst-case" failure analysis of a stemmed, porous-coated tibial revision component that was designed with "slots" to aid in removal. A three-dimensional FEM model of a metal-backed tibia! component was subjected to expected peak loads while being restrained at the stem and unsupported under the plateaus. Stresses in the prosthesis plateau adjacent to the stem were found to exceed yield stress in many areas, and to exceed the expected endurance limit in large areas. We conclude that a stemmed prosthesis with slots is flawed and may be expected to fail if implanted without adequate support for the prosthesis plateau. The long-term effects of bone remodeling may further jeopardize the integrity of this prosthesis. We recommend that this prosthesis not be used in its present design.

Early Tibial Baseplate Fracture After Medial Unicondylar Knee Arthroplasty

“…There are fewer than 100 case reports in the literature of TKA tibial baseplate fractures 10 . Critical factors implicated in the failures include prosthesis design, implant positioning and fixation, tibial bone stock, obesity, and high activity level 8,[10][11][12][13][14][15][16][17][22][23][24][25] . Chatterji et al 10 , Abernathy et al 13 , and Flivik et al 16 all indicated that manufacturing errors and deficiency in implant design are also relevant factors.…”