According to the invention, the process includes the steps of : a) taking a sagittal preoperative x-ray of the vertebral column of the patient to be treated, extending from the cervical vertebrae to the femoral heads； b) on that x-ray, identifying points on S1, S2, T12 et C7 ； c) depicting, on the said x-ray, curved segments beginning at the center of the plate of S1 et going to the center of the plate of C7 ； e) identifying, on that x-ray, the correction(s) to be made to the vertebral column, including the identification of posterior osteotomies to make； f) pivoting portions of said x-ray relative to other portions of that x-ray, according to osteotomies to be made； g) performing, on said x-ray, a displacement of the sagittal curvature segment extending over the vertebral segment to be corrected； h) from a straight vertebral rod (TV), producing the curvature of that rod according to the shape of said sagittal curvature segment in said displacement position.
