An intervertebral prosthetic device is provided for implanting within an intervertebral disc space between first and second vertebral bodies. The device includes first and second components respectively adapted to engage the first and second vertebral bodies. A non-articular, elongate flexible core component is interposed between the first and second components, and one or more flat tethers are coupled to the first and second components to bind together the components and the core to constrain motion of the intervertebral prosthetic device when in operable position between the vertebral bodies. In various embodiments, the first and second components include first and second covers, and the elongate, flexible core includes regions of different elasticity. Further, the non-articular core is fixedly secured to the first and second components, and the flat tether is a flexible, braided textile-based structure. The prosthetic device is a posteriorally inserted intervertebral prosthetic device in various configurations.