An expandable intervertebral implant (210; 410) comprising: top and bottom plates (220, 250; 420, 450) having inner and outer surfaces (226, 256, 224, 254; 426, 456, 424, 454), the inner surfaces facing each other and each having a ramp surface (222, 252; 422; 452); an actuator (280; 480) situated between the inner surfaces of the top and bottom plates; and first and second expansion members (300, 302; 500, 502) coupled to the actuator (280; 480) and located between the inner surfaces of the top and bottom plates (220, 250; 420, 450), the expandable intervertebral implant (210, 410) being characterized in that the first and second expansion members each have a horizontal portion with at least one projection (316; 516) extending outward therefrom, wherein rotation of the actuator (280; 480) in opposing directions causes the horizontal portion of the first and second expansion members (300, 302; 500, 502) to translate along the ramp surfaces (222, 252; 422; 452) toward and away from one another along a longitudinal axis of the actuator, resulting in movement of the top and bottom plates (220, 250; 420, 450) along a vertical axis perpendicular to the longitudinal axis, the projections (316; 516) of the horizontal portions being received within at least one lateral slot (318; 518) situated adjacent each ramp surface (222, 252; 422, 452) as the top and bottom plates (220, 250; 420, 450) move along the vertical axis and wherein the inner surfaces (226, 256; 426, 456) of the top and bottom plates (220, 250; 420, 450) each include a recess (230, 430) adjacent the respective ramp surface (222, 252; 422, 452), and the first and second expansion members (300, 302; 500, 502) each include a vertical portion (312, 314; 512, 514) adapted to translate along the longitudinal axis of the actuator within the recesses during movement of the top and bottom plates along the vertical axis. top and bottom plates (220, 250; 420, 450) having inner and outer surfaces (226, 256, 224, 254; 426, 456, 424, 454), the inner surfaces facing each other and each having a ramp surface (222, 252; 422; 452); an actuator (280; 480) situated between the inner surfaces of the top and bottom plates; and first and second expansion members (300, 302; 500, 502) coupled to the actuator (280; 480) and located between the inner surfaces of the top and bottom plates (220, 250; 420, 450), the expandable intervertebral implant (210, 410) being characterized in that the first and second expansion members each have a horizontal portion with at least one projection (316; 516) extending outward therefrom, wherein rotation of the actuator (280; 480) in opposing directions causes the horizontal portion of the first and second expansion members (300, 302; 500, 502) to translate along the ramp surfaces (222, 252; 422; 452) toward and away from one another along a longitudinal axis of the actuator, resulting in movement of the top and bottom plates (220, 250; 420, 450) along a vertical axis perpendicular to the longitudinal axis, the projections (316; 516) of the horizontal portions being received within at least one lateral slot (318; 518) situated adjacent each ramp surface (222, 252; 422, 452) as the top and bottom plates (220, 250; 420, 450) move along the vertical axis and wherein the inner surfaces (226, 256; 426, 456) of the top and bottom plates (220, 250; 420, 450) each include a recess (230, 430) adjacent the respective ramp surface (222, 252; 422, 452), and the first and second expansion members (300, 302; 500, 502) each include a vertical portion (312, 314; 512, 514) adapted to translate along the longitudinal axis of the actuator within the recesses during movement of the top and bottom plates along the vertical axis.