The present disclosure relates to the field of spine disc implants. Exemplary embodiments of the disclosed spinal disc implants advantageously and ultimately provide fusion with the body of the vertebra and stabilization of the spine in an anatomically correct position, e.g., in cervical, thoracic and/or lumbar regions. More particularly, the present disclosure is directed to a disc implant that addresses and overcomes the shortcomings of the prior implants by providing first and second inter-vertebral elements that are movably coupled relative to each other and are adapted to permit bone in-growth over time. Thus, the disclosed spinal disc implants permit relative movement between the first and second inter-vertebral elements upon implantation and after the patient is mobilized&mdash；thereby permitting the implant to assume a desired position based on the specific and unique spinal balance of the patient in an initial post-implantation period&mdash；but then the first and second inter-vertebral elements become fixed relative to each other (i.e., fused). The present disclosure also provides advantageous instrumentation and associated methods for positioning a spine disc implant in a desired anatomical location.
