Devices and methods are provided for optimized spinal fixation using additive manufacturing techniques to create implants with optimized structure for various surgical approaches, anatomies, etc. One exemplary embodiment includes a cage having an X-shaped connection that can bear a load during cage impaction. The cage can be additively manufactured to incorporate features such as variable wall thickness or material density to adjust properties of the cage, including load bearing capability, flexibility, radiolucency, etc. The cage can further include one or more of the connectors disposed between upper and lower endplates. In some embodiments, the cage can include a feature for coupling an insertion device thereto for introducing the cage into the body of a patient. In some embodiments, a plate can be appended to or integrally formed with a proximal end of the cage to assist with securing the cage to vertebral bodies.