A system for accessing a spine from a curved postero-lateral approach may include a curved cannula positioned along a curved path from an opening in the skin to a location proximate the spine. A guide member may be first inserted to establish the path between the tissues and fascia, and one or more intermediate cannulas may be temporarily inserted over the guide member to dilate the tissues prior to insertion of the main cannula. An interbody device may be implanted in an intervertebral space through the cannula. The system may include a guide bar removably coupled to a targeting post. The targeting post may be inserted adjacent the spine to provide a target, and the guide bar may be removably attached to the guide member, to guide it along the path to the target location. An external support arm may be secured to any other component of the system.