Entfernung von Al2O3-Restpartikeln von der Oberfläche korundgestrahlter Titanimplantate durch die ALFREDS-Oberflächenbehandlung : Effekt auf die Biokompatibilität, Osteointegration und Scherhaftfestigkeit in-vivo

BACKGROUND. Cementless endoprosthetic devices are grit-blasted with Al2O3 particles to increase surface roughness and enhance the implants´ osseous integration. Grit blasting leads to an embedding of Al2O3 particles which subsequently cover 24% to 42% [1,2] of total surface area. Dislocated into the joint space, Al2O3 causes abrasive wear of arthroplastic devices and increases metal-ion release. Apart from third-body wear, Al2O3 particles activate macrophages and inhibit bone formation. The ALFREDS-surface treatment removes approx. 96% of residual Al2O3 particles from implant surfaces, while retaining the original micro-topography. The aim of the present in-vivo study was to investigate the new surface treatment and its effect on osseous integration applied to two different metals, with a conventional grit-blasted surface serving as control.METHODS: 76 cylinders of Al2O3-blasted cpTi or Ti6Al7Nb were implanted into the distal femoral metaphysis of 38 rabbits and harvested 28 days or 56 days after surgery. Half of the implants of each raw material were cleaned with the ALFREDS surface treatment. Surface roughness and composition were controlled by Energy-Dispersive-X-ray, Back-Scattering-Electron and non-contact-profilometry. Manual testing of the implant stability and radiographs were performed for each implant. The mechanical strength of the implant-bone interface was quantified on 40 implants using a pushout test. 36 samples were investigated histologically and by scanning electron microscopy (SEM). Computer-assisted histomorphometry was applied to quantify the amount of osteointegration. Statistical analysis was performed with ANOVA.RESULTS. Blinded histological and SEM analysis revealed the ALFREDS treatment to be fully biocompatible. All surfaces exhibited early bone repair, without differences of the implant-bone interface or inflammatory reaction at any time point (28/56 days). Radiographs and histology showed signs of osteolysis in 2 conventional Al2O3-blasted implants. In histomorphometry, the Al2O3-free implants exhibited a significantly higher percentage of osteointegration (p<0.015), irrespective of implant material. Contrastingly, push-out testing revealed consistently higher shear stresses and mechanical interlocking of the conventional, grit-blasted implants at both time points (p=0.06). No statistical significant differences were found between the two raw materials, but Ti6Al7Nb-implants archieved better osteointegration (p=0.21) and higher shear stresses (p=0.19). CONCLUSIONS. The ALFREDS-surface treatment effectively removes particulate Al2O3 from implants. This leads to reduced mechanical interlocking, but significantly higher osteointegration. The technology is biocompatible and could provide long-term clinical benefits, as particle shedding into the joint space is virtually eliminated. Clinical studies are required to determine long-term effects on implant survival.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2010

Author dc:creator

• Gensior, Tobias Johannes

Contributors dc:contributor

• Erli, Hans Josef Ludwig

• info:eu-repo/classification/ddc/610
• Endoprothese
• Korundstruktur
• Aluminiumoxide
• Titan
• Gelenkendoprothese
• Medizin
• Korundstrahlen
• Osteointegration
• Scherhaftfestigkeit
• arthroplasty
• grit-blasting
• aluminumoxide
• titanium
• osseointegration

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124615%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:63160