The patellofemoral joint surface of the femur of New Zealand white rabbit was drilled to create a cylindrically shaped full-thickness defect (4(ψ)×7(l)). A hydroxyapatite-based scaffold for born regeneration (Neobone) was implanted into the defect with bone morphogenetic protein (BMP). Eight and thirteen, months after the implantation, the cylindrically shaped cartilage/bone plug was extracted from the joint surface, and was subjected to static and dynamic compression tests and a friction test. Results revealed that, 13 months after the implantation, the tangent modulus of the regenerated cartilage almost recovered -to control level in static compression test although the deformation rate remained much higher than control level in dynamic compression test. The friction coefficient of the regenerated cartilage recovered to control level 8 months after the implantation. These results suggest that the mechanical properties of the cartilage regenerated by Neobone with BMP for 1 year recover well except for dynamic compression property.
