An intervertebral implant system consisting of a single pair of screws (16,18) installable between a pair of vertebrae to provide a space between the pair of vertebrae defined by a spacer of the intervertebral implant system, the implant system comprising: the spacer having top and bottom surfaces locatable to fit in the space between the pair of vertebrae and having a rear sidewall having a screw aperture for passage of a first screw and angled to orient the first screw into a first vertebrae of the pair of vertebrae at an angle relative to the rear sidewall of the spacer so that the first screw will enter an endplate of the first vertebrae at an angle of about 30 to about 50 degrees relative to the top and bottom surfaces of the spacer; and a plate installable onto the rear sidewall of the spacer, the plate comprising: an interior side for abutting the rear sidewall of the spacer and an opposite outer side, an angled screw aperture that extends in an angled direction between the interior side and the outer side of the plate and is aligned with the screw aperture of the spacer when the plate is installed on the spacer, wherein the first screw is received by the angled screw aperture and then passes through the screw aperture of the spacer to enter an endplate of the first vertebrae, and a single elevated screw support extending upwardly or downwardly from the plate so as to extend opposite the direction of the angled screw aperture, the elevated screw support including an aperture for receiving a second screw and oriented substantially normal to the outer side of the plate and substantially parallel to the top and bottom surfaces of the spacer to locate the second screw to enter a second vertebrae of the pair of vertebrae through an anterior surface of the second vertebrae. the spacer having top and bottom surfaces locatable to fit in the space between the pair of vertebrae and having a rear sidewall having a screw aperture for passage of a first screw and angled to orient the first screw into a first vertebrae of the pair of vertebrae at an angle relative to the rear sidewall of the spacer so that the first screw will enter an endplate of the first vertebrae at an angle of about 30 to about 50 degrees relative to the top and bottom surfaces of the spacer; and a plate installable onto the rear sidewall of the spacer, the plate comprising: an interior side for abutting the rear sidewall of the spacer and an opposite outer side, an angled screw aperture that extends in an angled direction between the interior side and the outer side of the plate and is aligned with the screw aperture of the spacer when the plate is installed on the spacer, wherein the first screw is received by the angled screw aperture and then passes through the screw aperture of the spacer to enter an endplate of the first vertebrae, and a single elevated screw support extending upwardly or downwardly from the plate so as to extend opposite the direction of the angled screw aperture, the elevated screw support including an aperture for receiving a second screw and oriented substantially normal to the outer side of the plate and substantially parallel to the top and bottom surfaces of the spacer to locate the second screw to enter a second vertebrae of the pair of vertebrae through an anterior surface of the second vertebrae. an interior side for abutting the rear sidewall of the spacer and an opposite outer side, an angled screw aperture that extends in an angled direction between the interior side and the outer side of the plate and is aligned with the screw aperture of the spacer when the plate is installed on the spacer, wherein the first screw is received by the angled screw aperture and then passes through the screw aperture of the spacer to enter an endplate of the first vertebrae, and a single elevated screw support extending upwardly or downwardly from the plate so as to extend opposite the direction of the angled screw aperture, the elevated screw support including an aperture for receiving a second screw and oriented substantially normal to the outer side of the plate and substantially parallel to the top and bottom surfaces of the spacer to locate the second screw to enter a second vertebrae of the pair of vertebrae through an anterior surface of the second vertebrae.