Effects of interference assembly of a tibial insert on the tibiofemoral contact mechanics in total knee replacement

Abstract

Tibial locking mechanism design is adopted to limit the backside micromotion in fixed-bearing total knee replacement. However, the effect of the interference assembly of a tibial insert on the tibiofemoral contact mechanics was usually ignored. Finite element model of a fixed-bearing total knee replacement with full peripheral locking mechanism was established to simulate the interference assembly of the tibial insert, and the corresponding effects on the tibiofemoral contact mechanics were predicted. Due to the interference assembly of the tibial insert, a maximum Mises stress of 3.24 MPa was found for the tibial insert before loading. Furthermore, the contact stress was increased by 8.77%, and the contact area was decreased by 5.43% under peak load. The interference assembly of the tibial insert in a fixed-bearing total knee replacement changed the tibiofemoral contact mechanics. This study indicated that the level of interference fit should be cautiously designed for the tibial locking mechanism in fixed-bearing total knee replacement for balancing the articular surface wear and the backside wear of the modular tibial insert.

Towards the understanding of lubrication mechanisms in total knee replacements – Part I: Experimental investigations

“…Generally speaking, the wear performance of TKA depends on in vivo loading, design factors of the implant, and surgical and patient-specific factors. For example, polyethylene damage in a TKA may depend on gait characteristics [18] or the locking mechanism of the polyethylene insert in the metal tray [19]. Despite all the technological developments, the material characteristics of the implant play an important role [20].…”

Stress response envelopes of intact tibiofemoral joint and knee osteoarthritis

“…The prevalence of knee pain increased with age and was highest among the older residents aged 60-69 years and the prevalence was higher among females than males. 3 While computational stress analysis of the knee joint has been reported in several publications, [4][5][6][7][8][9][10][11][12][13][14][15] there are still many aspects that require more investigation. The first aim of this study was to determine stress envelopes of an intact tibiofemoral joint in response to different axial load levels, external-internal rotation and varusvalgus motion scenarios.…”