Experimental Study Regarding the Comparative Behavior of Three Osteoconductive Bone Graft Substitutes

The aim of this study is to reveal the integration, bone reaction and and extent of osseous healing for 3 types of osteoconductive graft substitutes used on experimental bone defects performed in rabbit femurs. The authors have performed an in vivo study on 2 groups of 6 rabbits with induced bone defect in distal femoral epiphysis. There have been used 3 types of BGS: Eurocer 400 (FH Orthopedics) - a biphasic BGS (55% hydroxyapatite and 45% tri-calcium phosphate), as granules, Euro bone (FH Orthopedics) an injectable BGS (55% bi-calcium phosphate and 45% tri-calcium phosphate), Osteoset (Wright) - calcium sulphate BGS as pellets. The bone defect in the first group was filled with Eurocer400 on the right femur and with Osteoset in the left femur. In the second group, the bone defect on the right femur was filled with Eurobone and the left femur with Eurocer400. The rabbits were sacrificed at 2 months after bone graft implantation and radio logic and histological examination were performed. Periimplant bone fragments were cut, processed and decalcified. Serial sections were stained by hematoxylin-eosin and van Gieson tehcnique. X-ray examination showed a good Osseo integration for Eurocer and Eurobone. The 2 main disadvantages of Osteoset pellets are the poor biological integration and fast resorbtion. However, we have remarked a poor density of the material at 2 months post-implantation, with important fragmentation at the implantation place. Eurocer and Eurobone showed a good Osseo integration with new bone formation. Osteoset pellets must be reserved to cavity defects with small contact area with fluid, thus avoiding the BGS to dissolve too fast. However, calcium sulphate Osteoset can be used as carrier for antibiotics, as well as of bone inductive molecules.