This invention relates to a method of preoperative planning to correct spine (1) misalignment of a patient, comprising a step of making a translation and a rotation, in a sagittal plane, of each vertebra (2) of a set of several cervical and/or thoracic (T1-T12) and/or lumbar (L1-L5) imaged spine vertebrae (2), so that said set of imaged vertebrae (2) presents afterwards, in the sagittal plane, the same cervical lordosis and/or the same thoracic kyphosis and/or the same lumbar lordosis as a model adapted for said patient, wherein it also comprises, before said step of making said translation and said rotation in a sagittal plane: a step of making a translation and a rotation, in a coronal plane, of each vertebra (2) of said set of several cervical and/or thoracic (T1-T12) and/or lumbar (L1-L5) imaged spine vertebrae (2), so that said set of imaged vertebrae (2) becomes straight in said coronal plane, and of making a rotation, in an axial plane, of each vertebra (2) of said set of several cervical and/or thoracic (T1-T12) and/or lumbar (L1-L5) imaged spine vertebrae (2), so that said set of imaged vertebrae (2) becomes axially aligned.
