Purpose Some clinical situations, such as great sagittal imbalance, high-grade isthmic spondylolisthesis or sacral malunion could require a sacral osteotomy to decrease pelvic parameters, horizontalize the sacrum or correct sacral malunion. Here is described a novel technique to perform a sacral osteotomy to decrease pelvic parameters with a lumbo-pelvic construct, with first a sacral slope decrease, then a pelvic tilt decrease. Methods Simulations have been performed using tridimensional reconstructions of the lumbar spine and pelvis, made from CT-scan images of a healthy individual. A cadaveric study has then been performed. Results 3D modeling exhibited linear relationship between osteotomy angle and pelvic incidence correction, through multiple simulations with 1° increment. Cadaveric study demonstrated feasibility. Conclusion This preliminary work shows that this technique is efficient to decrease pelvic parameters. A linear relationship has been exhibited between osteotomy angle and PI decrease, as per the following formula: osteotomy angle = PI change/0.84. Previous article in issue