Stand alone interbody fixation system

An interbody spacer system for insertion between a first vertebra and a second vertebra, the interbody spacer system comprising:

• an interbody spacer having an outer wall, a first surface, and a second surface, the first surface configured to engage a first endplate of the first vertebra, the second surface configured to engage a second endplate of the second vertebra;
• a first entry aperture in the outer wall and a first exit aperture on the first surface;
• a first helical passageway defining only a first helical path, the first helical passageway in communication with the first entry aperture and the first exit aperture;
• and
• a first blade that includes a first base and a first helical body that extends from the first base to a first distal tip, wherein the first helical body is configured to enter the first entry aperture, extend along the first helical path through the first helical passageway, and exit through the first exit aperture, wherein upon rotation of the first base the first helical body is configured to enter the first endplate through a first location in the first endplate and exit the first endplate through a second location in the first endplate such that a portion of the first helical body is disposed inside the first vertebra between the first location and the second location and the first distal tip extends generally toward the first surface, wherein the first blade is configured to anchor the spacer to the first vertebra at the first location and the second location.