Viscoelastic material models for more accurate polyethylene wear estimation

Isolated polyethylene exchange versus acetabular revision for polyethylene wear.

UNLABELLED Polyethylene wear and osteolysis are not uncommon in THA mid- and long-term. In asymptomatic patients the dilemma faced by the orthopaedic surgeon is whether to revise the cup and risk damage to the supporting columns and even pelvic discontinuity or to perform isolated polyethylene exchange and risk a high rate of postoperative recurrent instability and dislocation that will necessi...

Are discrete models more accurate?

Newton’s second law describes the motion of the center of mass of most objects that we encounter in everyday life, including the complex motion of a spoon when we eat, the acceleration of a car, and even the trajectories of planets and stars. Only if objects move extremely fast, do we need to replace Newton’s second law with Einstein’s theory of relativity, and only if objects are extremely sma...

Generalized Fractional Maxwell Model: Parameter Estimation of a Viscoelastic Material

In this paper, we show how fractional viscoelastic models can be efficient in the modeling of linear viscoelastic behavior, increasing the fitting accuracy of classic generalized viscoelastic models, such as the Generalized Maxwell model. Experimental data (Loss and Storage modulus in the frequency domain) were retrieved from a Dynamic Mechanical Analysis test considering Carbon Fibre Reinforce...

Polyethylene Wear Rates Of Postmortem TKR Contrasted Against THR Manufactured From Identical Material

Polyethylene Wear Debris From a Knee Simulator Model: Effect of Crosslinking and Counterface Material

INTRODUCION: Improved wear resistance of crosslinked UHMWPE has been well demonstrated in both hip and knee [1-4]. A reduction of 70% can be shown in knee simulators from conventional crosslinked tibial inserts (CXPE) gamma-irradiated at 3.5Mrad to 7Mrad highly crosslinked inserts (HXPE). Hip simulator models indicated that debris size decreased with increased crosslinking [5]. In the knee it h...