AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP38
A Scanning Small Angle X-Ray Scattering (SAXS) Study of the Nanometer Length Scale Bone Structure in Connection with Implants

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: M. Foss, University of Aarhus, Denmark
Authors: M. Foss, University of Aarhus, Denmark
M.H. Bunger, University of Aarhus, Denmark
K. Erlacher, University of Aarhus, Denmark
L. Haisheng, Aarhus University Hospital, Denmark
Z. Xuenong, Aarhus University Hospital, Denmark
B.L. Langdahl, Aarhus University Hospital, Denmark
F. Besenbacher, University of Aarhus, Denmark
J.S. Pedersen, University of Aarhus, Denmark
Correspondent: Click to Email
The understanding of the interaction between bone and orthopaedic implants is important for the development of biomaterials with improved biocompatibility. The SAXS technique has previously been applied to offer structural information on mean crystal thickness, predominant orientation and degree of orientation of mineral particles in bone. Therefore, one possible application of SAXS is to investigate the nanostructure of bone in connection with ingrowth on implants, which is not possible with conventional optical techniques. Three sections of pig vertebrae with a thickness of 190µm were examined. One sample included the neurocentral growth zone, while the other two were sections with bone and pieces of either titanium or tantalum implants. Bone provided a strong SAXS signal and relatively low transmission intensity, whereas regions within the neurocentral growth zones showed a high transmission as well as a high SAXS signal. Combining the transmission and the SAXS data, it was possible to differentiate between areas of fibrous tissue and bone. This was supported by elemental analysis performed by SEM-EDAX. The mineral particles in the cancellous bone were aligned along the trabeculae, with less orientation close to the growth zone. Also, the mineral particles tended to be aligned along the implant surfaces. Within the individual bone samples, a large variation in all SAXS parameters were observed depending on the bone position relative to the implant. Furthermore, larger particle thicknesses were found in areas of bone formation, which matches our growth zone data. The data suggests that the parameters obtained by SAXS can be used to assay the local mineral particle growth. This indicates that SAXS is a powerful tool for the characterization of the detailed mineral structure of bone in the vicinity of implants.