Spinal fusion implant

1. A system for forming a rigid structure between adjoining vertebrae in a patient, the system comprising:

an implant comprising:

a cage defined by at least a first end, second end, first side, and second side surface, wherein first and second side surfaces extend substantially parallel to each other to span a space between adjoining vertebrae and first and second ends interconnect said first side surface and second side surface;

one or more flexible joints incorporated into the cage allowing the cage to be deformed for insertion into a patient; and

surface configurations projecting out of at least one of the first and second side surfaces of the cage for slidably attaching the implant to an insertion guide;

wherein the one or more flexible joints allow the cage to conform to the shape of the insertion guide as the implant is slid along the length of the insertion guide; and

an insertion guide configured to interface with the surface configurations of the implant for positioning the implant during insertion.

2. The system of claim 1 , wherein the insertion guide has a curved distal end for positioning the implant in the space between adjoining vertebrae.

3. The system of claim 2 wherein the one or more flexible joints allow the cage to conform to the shape of the insertion guide.