Intervertebral spacer device utilizing a spirally slotted belleville washer having radially extending grooves

摘要

An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. In a preferred embodiment there is a single such belleville washer which is modified to mount onto a ball-shaped head. The lower plate of this embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The modified belleville washer can be rotatably mounted to the head such that the wider portion of the washer seats against the upper plate.