An intervertebral fusion system comprising: a spacer extending from a proximal portion to a distal portion and having an upper guide and a lower guide, wherein the upper guide extends from the proximal portion a distance towards the distal portion of the spacer, wherein the spacer is adapted to be implanted between an upper vertebral body and a lower vertebral body, wherein the upper guide further comprises an upper inclined surface that is curvilinear; and an anchoring device having an upper anchor (118; 218) and a lower anchor (120; 220), the upper and lower anchors (118, 120; 218, 220) having a body with an anchor tip and proximal end, located proximal from anchor tip, a first prong, a second prong each extending in a proximal direction away from anchor tip,and a central groove extending between first prong and second prong, the groove tapers from a narrow end proximate to anchor tip to a wide end proximate to proximal end to define the body as a generally V-shaped body, wherein the proximal end includes two enlarged proximal tips separated by the central groove, the upper and lower anchors (118, 120; 218, 220) being movable between a first position, wherein the anchor tip is disposed inside the spacer and a second position wherein the anchor tip is extended outwardly from the spacer, characterised in that - each of first prong and second prong comprises a first retention groove (266, 268) respectively, proximate to anchor tip and narrow end of groove, and a second retention groove (270, 272) distal from anchor tip and proximate to wide end of groove. - wherein each of first and second prongs (260, 262) at proximal end includes a proximal tip adjacent to each second retention groove (270, 272) wherein the proximal tips are enlarged in dimension relative to the remainder of the anchor (218, 220) - the two enlarged proximal tips are defined at least in part by the retention grooves (270, 272) and have a lateral side extending laterally outwardly from each second retention groove (270, 272) and include an insertion tool insertion indent (280, 282) that is a generally hemispherical indent sized to accept a detent in an insertion tool. a spacer extending from a proximal portion to a distal portion and having an upper guide and a lower guide, wherein the upper guide extends from the proximal portion a distance towards the distal portion of the spacer, wherein the spacer is adapted to be implanted between an upper vertebral body and a lower vertebral body, wherein the upper guide further comprises an upper inclined surface that is curvilinear; and an anchoring device having an upper anchor (118; 218) and a lower anchor (120; 220), the upper and lower anchors (118, 120; 218, 220) having a body with an anchor tip and proximal end, located proximal from anchor tip, a first prong, a second prong each extending in a proximal direction away from anchor tip,and a central groove extending between first prong and second prong, the groove tapers from a narrow end proximate to anchor tip to a wide end proximate to proximal end to define the body as a generally V-shaped body, wherein the proximal end includes two enlarged proximal tips separated by the central groove, the upper and lower anchors (118, 120; 218, 220) being movable between a first position, wherein the anchor tip is disposed inside the spacer and a second position wherein the anchor tip is extended outwardly from the spacer, characterised in that - each of first prong and second prong comprises a first retention groove (266, 268) respectively, proximate to anchor tip and narrow end of groove, and a second retention groove (270, 272) distal from anchor tip and proximate to wide end of groove. - wherein each of first and second prongs (260, 262) at proximal end includes a proximal tip adjacent to each second retention groove (270, 272) wherein the proximal tips are enlarged in dimension relative to the remainder of the anchor (218, 220) - the two enlarged proximal tips are defined at least in part by the retention grooves (270, 272) and have a lateral side extending laterally outwardly from each second retention groove (270, 272) and include an insertion tool insertion indent (280, 282) that is a generally hemispherical indent sized to accept a detent in an insertion tool. - each of first prong and second prong comprises a first retention groove (266, 268) respectively, proximate to anchor tip and narrow end of groove, and a second retention groove (270, 272) distal from anchor tip and proximate to wide end of groove. - wherein each of first and second prongs (260, 262) at proximal end includes a proximal tip adjacent to each second retention groove (270, 272) wherein the proximal tips are enlarged in dimension relative to the remainder of the anchor (218, 220) - the two enlarged proximal tips are defined at least in part by the retention grooves (270, 272) and have a lateral side extending laterally outwardly from each second retention groove (270, 272) and include an insertion tool insertion indent (280, 282) that is a generally hemispherical indent sized to accept a detent in an insertion tool.