• Ding, Ming
• Babiker, Hassan
• Overgaard, Søren

Abstract

Best Poster 5Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants <strong>AuthorsBabiker , H.; Ding M.; Overgaard S.<strong>InstitutionOrthopaedic Research Laboratory, Department of Orthopaedic Surgery, Odense University Hospital, Clinical Institute, University of Southern Denmark, Denmark<strong>Abstract</strong>Replacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standard for bone replacement. However, there are several disadvantages such as donor site pain and bacterial or viral contamination. Thus, there is need for development of alternative bone graft materials. The use of osteoinductive materials such as demineralized bone matrix (DBM) alone or in combination with allograft or commercially available human cancellous bone (CB) may substitute allo- and autograf as they have the capability of inducing new bone and improving implant fixation through enhancing bone ingrowth. The purpose of this study was to investigate the effect of DBM alone or with CB on the fixation of porous-coated titanium implants.<strong>Material and Methods</strong>DBM100 (pure DBM) and CB produced from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested. The implant fixation was evaluated by mechanical push-out testing to test shear mechanical properties between implant and the host bone2. Non-parametric tests were applied.<strong>Discussion and Conclusion</strong>Result: The strength of the DBM group was 0.026 MPa, which was statistically significant lower than the other three groups. The strength of the DBM/CB was 0.76 MPa (P=0.03 relative to the DBM), the DBM/allograft 1.12 MPa (P=0.02), and the allograft 0.93 MPa (P=0.02) Conclusion: This study investigated the efficacy of commercially available demineralized bone matrix and human cancellous bone on implant fixation. Our data have revealed that by adding DBM to allograft or to CB resulted in comparable mechanical properties relative to allograft. We found no early effect of DBM alone on the fixation of porous coated titanium implant in this animal model, while the long term effects have to be investigated. Our results are in accordance with Cook et al3 however in a press fit model which is not as clinical relevant as the gap model used in the present study. Our data have clearly demonstrated that the combination of DBM with CB, which can be used off the shelf, may represent an alternative to allograft. References 1. Overgaard, S., Acta Ortopaedica Scandinavica, suppl. 297,71. 2000. 2. Ding, M., Acta Ortopaedica Scandinavica, 71, 2-45, 2000. 3. Cook SD, Salked SL, Patron LP, Barrack RL. J Arthroplasty. 2002 jun; 17 (4):402-8 </strong></strong>

Topics

• porous
• impedance spectroscopy
• gold
• strength
• titanium
• titanium alloy