Adhesion and reliability of interfaces in cemented total joint arthroplasties

Abstract

Debonding of the prosthetic/polymethylmethacrylate interface has been implicated in the initial failure process of cemented total hip arthroplasties. However, little quantitative understanding of the debonding process, as well as of the optimum interface morphology for enhanced resistance to debonding, exists. Accordingly, a fracture-mechanics approach has been used in which adhesion at the interface is characterized in terms of the interface fracture energy, G (J/m2), and shown to be a strong function of the morphology, debonding length, and loading mode of the interface. Double-cantilever-beam and four-point-flexure fracture-mechanics samples containing four clinically relevant prosthetic surface preparations were prepared to survey a range of interface roughness and loading modes. Adhesion at the interface could not be characterized with a single-valued material property but was found to exhibit resistance-curve behavior in which resistance to debonding increased with both the initial debond extension and the roughness of the interface. Values of debonding initiation, Go, were relatively insensitive to the roughness of the surface and the loading mode, whereas steady-state fracture resistance of the interface, Gss, increased significantly with the roughness and shear loading of the interface. These quantitative results suggest that debonding of the prosthetic/polymethylmethacrylate interface may be primarily attributed to surface interactions such as interlocking and the pullout of rough asperities that occur behind the debond tip. A simple mechanics analysis of such interactions was performed and revealed increases in the fracture resistance of the interface that were consistent with experimentally measured values.

Effects of fatigue loading and PMMA precoating on the adhesion and subcritical debonding of prosthetic-PMMA interfaces

“…Whereas previous investigations have only reported critical debond values, 12,[29][30][31] this study includes the important effect of salient interface parameters such as initial surface morphology (roughness), surface precoating, cement layer thickness, physiological environment, and debond length on both critical fracture resistance and subcritical debondgrowth rate behavior. Understanding the fatigue debonding behavior in particular is a prerequisite for improved lifetime predictions of cemented systems under alternating physiological loads and provides a quantitative basis for designing interfaces with improved long-term reliability.…”

“…This is consistent with the formation of a debond bridging zone behind the debond tip, where polymer ligaments may be left behind the debond tip as the debond extends, as previously reported. 12 In addition, wear debris at the prosthetic-PMMA interface was observed [ Fig. 7(a,d)].…”

“…12 It was demonstrated that interface debond resistance is a strong function of surface preparation and debond loading mode. In addition, interfaces exhibited resistance curve (R-curve) behavior, indicating an increasing resistance to debonding with initial debond extension.…”

“…The elastic property mismatch across the polymer-metal interface results in a mixed mode-loading condition characterized by a phase angle at the debond tip, tip 12,19 :…”

Peen treatment on a titanium implant: effect of roughness, osteoblast cell functions, and bonding with bone cement

“…6,7 The augmentation of the surface roughness or surface energy allows for developing mechanical interlock of the implant and bone cement interface, which can improve the bonding characteristics of the implant-cement interface. 8 Hosein et al 9 pointed out that circumferential-grooved stems offered improved stability under compression relative to the smooth stems. It has been revealed that porous coating of the femoral stems dramatically improved push-out strengths and fatigue properties of the stem-cement interface through increasing surface roughness.…”