A unitary intervertebral device, having no moving components is provided for non-fusion articulation and fusion applications. The interbody articulating device allows for limited flexion and rotation between the implant and an adjacent vertebra, helping to preserve or restore near-normal motion between adjacent vertebrae. Rotational motion is achieved through one or more protrusions incorporated into the spinal interbody device. In one articulating form, a first protrusion extends perpendicularly from one bearing surface of the interbody device to form a rotational protrusion, while at least a second protrusion extends from the opposite bearing surface of the interbody device to form a non-rotational protrusion. In another form, a single protrusion extends axially from one bearing surface of the interbody device to form a spike or anchoring, rotating protrusion, while the opposite bearing surface may be slightly rounded and/or comprising a bone-ingrowth promoting surface. Similarly configured fusion salvage devices are also described.