The present invention is directed to a surgical implant for the fusion of two adjacent vertebrae with an upper plane for contacting an upper vertebral body and a lower plane for contacting a lower vertebral body and a tubular structure, wherein the tubular structure is formed by a plurality of tubes running from the upper plane to the lower plane and in substantially horizontal direction throughout one side of the surgical implant straight to the opposite side of the surgical implant. This tubular structure has the advantage that the formation and ingrowth of new bone is promoted and advantaged and that the degree of formation and ingrowth of new bone is detectable by X-ray measurements.