Spinal cage devices, systems, and methods of assembly and implanting the devices and systems are disclosed. The cage system includes a cage and at least one locking screw assembly configured to couple to the cage. The spinal cage system includes a cage with a body portion, an external plate, and a rod. The body portion includes at least one opening positioned between the first and second ends, a center opening in the first end, and at least one hole adjacent the center opening. The external plate includes an opening and at least two holes on opposite sides of the opening. The rod extends through the center opening in the cage, the first end configured to couple to the external plate, and the second end positioned in the at least one opening. Methods for assembling a spinal cage system and for implanting a cage system are also disclosed.

Bone implants, assemblies, and methods thereof. The implants may include non-threaded triangular implants configured to promote fixation and fusion of the sacroiliac joint. The implants may have a triangular body configured to prevent or minimize rotational motion of the implant. The implants may include an inner core or an outer shell, which provides structural support for a lattice structure. The structural geometry may be generated through topology optimization software, such as finite element analysis, based on anatomical loading conditions for the implant.