This implant (1) for osseous fusion is intended to be inserted between two adjacent vertebral bodies (4) of a spinal column. It comprises a main body (2) having at least two longitudinal elements of C-shaped contour (2a, 2b) placed back to back and defining:--a solid axis (9), formed by the junction zone of said elements (2a, 2b) and suitable for being positioned parallel to the spinal column and for transmitting the stresses between the two adjacent vertebral bodies, and--at least two longitudinal apertures (6), suitable for holding grafts, oriented outward with respect to said solid axis (9).