A disc replacement device , comprising: a first body member having a convex articulation surface , an external inferior surface , a front aspect, a rear aspect and a first hole that is angled and extends from the front aspect thereof through the external inferior surface thereof; a second body member having a concave articulation surface , an external superior surface , a front aspect, a rear aspect and a second hole that is angled and extends from the front aspect thereof through the external superior surface thereof, wherein when operably positioned, the convex articulation surface of the first body member engages the concave articulation surface of the second body member to provide for movement therebetween, characterized by : bone fasteners extending through the first and the second holes to secure the device to a first vertebra and a second vertebra; and a locking device including a plate with at least one protrusion extending perpendicular from the plate and at least two screws for insertion through at least two openings in the plate and into the first body member and the second body member , wherein the locking device is configured to overlap a portion of the bone fasteners to restrict motion between the top and bottom members and wherein the external inferior surface of the first body member and the external superior surface of the second body member are arcuate such that the device has a generally cylindrical geometry. a first body member having a convex articulation surface , an external inferior surface , a front aspect, a rear aspect and a first hole that is angled and extends from the front aspect thereof through the external inferior surface thereof; a second body member having a concave articulation surface , an external superior surface , a front aspect, a rear aspect and a second hole that is angled and extends from the front aspect thereof through the external superior surface thereof, wherein when operably positioned, the convex articulation surface of the first body member engages the concave articulation surface of the second body member to provide for movement therebetween, characterized by : bone fasteners extending through the first and the second holes to secure the device to a first vertebra and a second vertebra; and a locking device including a plate with at least one protrusion extending perpendicular from the plate and at least two screws for insertion through at least two openings in the plate and into the first body member and the second body member , wherein the locking device is configured to overlap a portion of the bone fasteners to restrict motion between the top and bottom members and bone fasteners extending through the first and the second holes to secure the device to a first vertebra and a second vertebra; and a locking device including a plate with at least one protrusion extending perpendicular from the plate and at least two screws for insertion through at least two openings in the plate and into the first body member and the second body member , wherein the locking device is configured to overlap a portion of the bone fasteners to restrict motion between the top and bottom members and wherein the external inferior surface of the first body member and the external superior surface of the second body member are arcuate such that the device has a generally cylindrical geometry. <EOS>