Quantitative histomorphometric and biomechanic evaluation of spinal arthrodesis after biphasic calcium phosphate ceramic implantation in sheep

The effectiveness of a macroporous biphasic calcium phosphate ceramic was s tudied after laterovertebral arthrodesis in sheep. A ceramic with a TCP/HAP ratio of 35/65 was compared with autologous bone graft in an histomorphome tric and biomechanical point of wiev. Quantitative analysis of the results indicated that the biphasic ceramic allows an arthrodesis after 12 months, although control graft is effective after six months. A large decrease of f lexibility in all directions was obtained with the ceramic, similarly to au tologous graft. No nonfusion case was observed. In conditions very close to the human surgery, a pasterolateral fusion can be obtained using biphasic phosphate ceramic as bone substitute.