Osseointegration of porous titanium implants with and without electrochemically deposited DCPD coating in an ovine model

Abstract

BackgroundUncemented fixation of components in joint arthroplasty is achieved primarily through de novo bone formation at the bone-implant interface and establishment of a biological and mechanical interlock. In order to enhance bone-implant integration osteoconductive coatings and the methods of application thereof are continuously being developed and applied to highly porous and roughened implant substrates. In this study the effects of an electrochemically-deposited dicalcium phosphate dihydrate (DCPD) coating of a porous substrate on implant osseointegration was assessed using a standard uncemented implant fixation model in sheep.MethodsPlasma sprayed titanium implants with and without a DCPD coating were inserted into defects drilled into the cancellous and cortical sites of the femur and tibia. Cancellous implants were inserted in a press-fit scenario whilst cortical implants were inserted in a line-to-line fit. Specimens were retrieved at 1, 2, 4, 8 and 12 weeks postoperatively. Interfacial shear-strength of the cortical sites was assessed using a push-out test, whilst bone ingrowth, ongrowth and remodelling were investigated using histologic and histomorphometric endpoints.ResultsDCPD coating significantly improved cancellous bone ingrowth at 4 weeks but had no significant effect on mechanical stability in cortical bone up to 12 weeks postoperatively. Whilst a significant reduction in cancellous bone ongrowth was observed from 4 to 12 weeks for the DCPD coating, no other statistically significant differences in ongrowth or ingrowth in either the cancellous or cortical sites were observed between TiPS and DCPD groups.ConclusionThe application of a DCPD coating to porous titanium substrates may improve the extent of cancellous bone ingrowth in the early postoperative phase following uncemented arthroplasty.

Porous Titanium Implants: A Review

“…In a study by Khodaei et al it was proven that surface treatment with hydrogen peroxide resulted in about a 34% reduction in the compressive strength of the porous titanium implant. [151] Scislowska-Czarnecka et al evaluated porous titanium implants coated either with hydroxyapatite (HA), bioglass (BG), or calcium silicate by the sol-gel method. [150] As chemical treatment may disrupt the inner structure of the pores and affect the material's fatigue resistance, an interesting method for the prevention of such a scenario was proposed by Korobkova et al In their study, titanium foams were filled with molten wax before chemical treatment.…”

Evaluation of topographical and chemical modified TiAl6V4 implant surfaces in a weight‐bearing intramedullary femur model in rabbit

“…Schwarz et al detected a significantly increased implant anchorage for titanium plasma sprayed surfaces in comparison to sand or glasspearl blasted surfaces which raised further (not significantly) with additional brushite coating (Schwarz et al, ). Chen et al investigated plasma sprayed porous titanium surfaces with and without brushite coating in an ovine model and concluded from their analysis of the failure mode that the bone bonding strength might not increase with higher bone ingrowth but with increasing amounts of mature bone surrounding the implant (Chen et al, ). However, in their study, the brushite coating had no significant effect on mechanical stability (Chen et al, ).…”

“…Chen et al investigated plasma sprayed porous titanium surfaces with and without brushite coating in an ovine model and concluded from their analysis of the failure mode that the bone bonding strength might not increase with higher bone ingrowth but with increasing amounts of mature bone surrounding the implant (Chen et al, ). However, in their study, the brushite coating had no significant effect on mechanical stability (Chen et al, ).…”

Formability and mechanical properties of porous titanium produced by a moldless process

“…One of the popular approaches to addressing these problems is making the titanium porous. When the porosity is increased, the elastic modulus of titanium decreases and the surface roughness increases, which results in improved bone bonding 7, 8…”