US Patent 7771473 Expandable spinal fusion cage

An expandable spinal fusion device is provided. The expandable device comprises a first part slidingly coupled to a second part. An removable expandable member extends between the first part and the second part and is coupled to a rotating operator such that rotating the operator causes the first part and the second part to move away from each other and distract vertebral bodies. A spacer or clip is used to lock the first part in relation to the second part to allow bone growth the fuse the vertebral bodies.