A method is provided for expanding an intradiscal space between opposing vertebral bodies by expanding an expandable interbody fusion device and establishing an osteoconductive path between the opposing vertebral bodies through the device during expansion. The device is expanded by introducing at least one intermediate element between an upper element and a lower element to achieve ligamentotaxis. Each of the upper element, intermediate element and lower element comprises a region of porous biocompatible material coated or impregnated with material having relatively high osteoconductive and osteoinductive properties. During and upon expansion the regions are stress loaded by the opposing vertebral bodies to promote fusion between the vertebral bodies through the device.
