A spinal fusion device consisting of an osteoinductive composition that includes a carrier and an effective amount of a bone morphogenic protein, the composition being suitable for use in bone mass generation to fuse the adjacent vertebrae of a patient when said osteoinductive composition is introduced into a position between said vertebrae, in which the bone morphogenic protein is occluded within the carrier that is biodegradable and substantially impermeable to efflux of the bone morphogenic protein in vivo insufficiently so that the bone mass formed is substantially confined to the volume of the carrier when it is implanted and in which The carrier gradually exposes the occluded bone morphogenic protein as it is sedentary or reabsorbed and in which the biodegradable carrier further comprises a polymer-based carrier in which the polymer-based carrier forms a sponge matrix, the p-based carrier comprising olimer a polymer matrix and pores, in which the bone morphogenic protein is present in an amount of 0.5mg / ml to 4 mg / ml of the carrier, in which the bone morphogenic protein is selected from BMP-2 and BMP-7 and in which the amount of the osteoinductive composition is sufficient to deliver 2 mg of BMP to 40 mg of BMP.Un dispositivo de fusión espinal que consiste en una composición osteoinductora que incluye un portadory una cantidad eficaz de una proteína morfogénica ósea, siendo la composición adecuada para uso en la generaciónde masa ósea para fusionar las vértebras adyacentes de un paciente cuando se introduce dicha composiciónosteoinductora en una posición entre dichas vértebras, en la que la proteína morfogénica ósea está ocluida dentrodel portador que es biodegradable y sustancialmente impermeable a eflujo de la proteína morfogénica ósea in vivosuficientemente para que la masa ósea formada esté sustancialmente confinada al volumen del portador cuando seimplanta y en la que el portador expone gradualmente la proteína morfogénica ósea ocluida a medida que se
