Article

Effect of surgical fit on integration of cancellous bone and implant cortical bone shear strength for a porous titanium.

Surgical and Orthopaedic Research Laboratories-University of New South Wales, Sydney, Australia.
The Journal of arthroplasty (impact factor: 1.79). 02/2011; 26(7):1000-7. DOI:10.1016/j.arth.2010.12.007
Source: PubMed

ABSTRACT Porous scaffold dowels of Ti(6)Al(4)V were prepared and implanted into cancellous and cortical bone sites in adult sheep. Cancellous implants were examined under gap, line-to-line, and press-fit conditions, whereas line-to-line implantation was used in cortical sites. Cortical shear strength increased significantly with time and reached 26.1 ± 8.6 MPa at 12 weeks, accompanied by a concomitant increase in bone integration and remodeling. In cancellous sites, bone integration was well established at 4 and 12 weeks under conditions of press-fit and line-to-line match between implant and surgical defect. New bone growth was also found in the gap conditions, although to a lesser extent. These findings suggest that the porous Ti(6)Al(4)V could prove an effective scaffold material for uncemented fixation in cortical and cancellous sites.

0 0
 · 
0 Bookmarks
 · 
47 Views
  • Source
    Article: Osseointegration of porous titanium implants with and without electrochemically deposited DCPD coating in an ovine model.
    Dong Chen, Nicky Bertollo, Abe Lau, Naoya Taki, Tomofumi Nishino, Hajime Mishima, Haruo Kawamura, William R Walsh
    [show abstract] [hide abstract]
    ABSTRACT: Uncemented 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. Plasma 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. DCPD 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. The 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.
    Journal of Orthopaedic Surgery and Research 11/2011; 6:56.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

adult sheep
 
bone integration
 
Cancellous implants
 
concomitant increase
 
cortical
 
cortical bone sites
 
Cortical shear strength
 
cortical sites
 
effective scaffold material
 
gap conditions
 
line-to-line
 
line-to-line implantation
 
line-to-line match
 
New bone growth
 
Porous scaffold dowels