US Patent 7708778 Expandable articulating intervertebral implant with cam

An articulating expandable intervertebral implant for insertion between vertebrae of a human spine is described. The articulating expandable intervertebral implant includes an upper body that engages a first vertebra of the human spine, a lower body that engages a second vertebra of the human spine, and an elongated member. The superior surface of the lower body includes a channel. A portion of the inferior surface of the upper body may be substantially concave. The elongated member may include a cam portion along a length of the elongated member. The elongated member may be positioned in the channel of the lower body. The substantially concave portion of the upper body may contact the elongated member, such that rotation of the elongated member about a longitudinal axis of the elongated member increases a height and/or increases articulation of the intervertebral implant after insertion of the intervertebral implant.