The pathology of adult spinal deformity (ASD) includes various components such as malalignment of the sagittal plane, lower angle of lumbar lordosis, and pelvic retroversion [
1,
2]. The primary aim of surgery for ASD is to restore optimal patient-specific spino-pelvic-lower extremity alignment. Preservation of the lower lumbar and lumbar-sacral motion segments often results in implant failures, characterized by loosening or pullout of the pedicle screws, rod breakage, pseudarthrosis, or neurological deficits [
3,
4]. Therefore, extension of spine fusion to the sacrum represents a significant improvement of clinical outcomes and decreases major complications [
5]. Spino-pelvic fixation, stability, and correction of deformity have been reported with bilateral placement of single iliac screws [
6,
7]. Although a combination of this procedure was effective in protecting the sacral screws from failure and sacroiliac joint degeneration, sacro-pelvic fixation with bilateral S1 and bilateral single iliac screws for ASD was associated with breakage or back-out of iliac screws, screw loosening, rod breakage, or pseudarthrosis of L5–S1 within 5 years postoperatively [
8]. To overcome these complications, S2 alar iliac pelvic fixation has been developed and demonstrates better correction of pelvic obliquity with fewer complications [
2]. This technique should be performed under fluoroscopic guidance to place screws bilaterally, although it involves exposing patients and surgeons to radiation. Screw penetration of the iliac table and articular violation can occur. Previously, dual iliac screw fixation or a double-rod double iliac screw method were reported to provide rigid fixation in spino-pelvic reconstructions associated with destructive metastatic lesions at the lumbosacral junction, or in a case with a sacral tumor requiring total sacrectomy [
9]. Therefore, we have applied this method for ASD surgery using bilateral dual iliac screws as anchors in the ilium, and S1 screws to stabilize spino-pelvic fixation. The purpose of this study is to demonstrate the technique employing dual iliac screws and S1 pedicle screw fixation to fuse spino-pelvic lesions in ASD patients.