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 to the spine. Positioning of the distal end of a
radiolucent curved access cannula may be assisted by use of one or more
radio-opaque markers. Markers may be positioned to form a cross hair
image in fluoroscopy to assist in cannula placement. Radio-opaque inserts
placed in and extended beyond the curved access cannula may have
radiolucent windows to allow viewing of the cannula's radio-opaque
markers. An appropriately placed curved access cannula may be clamped to
prevent subsequent movement. Appropriate tools may be introduced through
the curved access cannula and the distal radio-opaque tool heads may be
viewed relative to the radio-opaque markers. The curved access cannula
may be attached to the spine through one or more screws.