Optimizing Spinal Realignment: A Comparative Analysis of Correction and Complications of Osteotomy Techniques in Adult Spinal Deformity

<sec><title>Background</title> Osteotomies are fundamental for correcting adult spinal deformity (ASD). This study sought to compare the effectiveness of anterior column realignment (ACR), pedicle subtraction osteotomy (PSO), intradiscal osteotomy (IDO), and Ponte osteotomies in achieving spinopelvic correction, clinical outcomes, and complications. </sec><sec><title>Methods</title> A retrospective analysis of 146 patients who underwent posterior fusions for ASD correction between 2016 and 2022 was conducted. Patients with ≥1 year of follow-up were included. Patients were grouped according to the osteotomies with the most significant impact on sagittal alignment change: IDO, PSO, ACR, or Ponte. Spinopelvic parameters—including pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), PI-LL mismatch, and sagittal vertical axis (SVA)—and their changes from pre- to postoperative images were compared. Surgical and clinical variables were collected, including mechanical complications (proximal junctional kyphosis, proximal junctional failure, different types of hardware failure, estimated blood loss, packed red blood cell transfusions, and length of stay). Clinical status was measured with the Oswestry Disability Index. Revision-free survival time was analyzed using Kaplan-Meier curves, with patients followed from index surgery until revision or last follow-up, and differences between osteotomy types were assessed. </sec><sec><title>Results</title> A total of 146 patients underwent ASD correction with IDO (<italic>n</italic> = 23), PSO (<italic>n</italic> = 21), ACR (<italic>n</italic> = 32), or Ponte (<italic>n</italic> = 70) osteotomies. Groups were comparable in age, body mass index, preoperative disability, and most spinopelvic parameters. PSO achieved the greatest sagittal correction (ΔLL = 29.7° ± 19.1°, ΔPI–LL mismatch = –24.75 ± 14.52, ΔSVA = –74.6 ± 51.6), IDO and ACR produced intermediate corrections, and Ponte produced the least. Estimated blood loss and packed red blood cell units transfused were lower in ACR and Ponte groups, corresponding to shorter instrumented constructs. Proximal junctional kyphosis occurred most frequently in ACR (31.3%) and Ponte (21.7%) groups, while the IDO group had the lowest rate (8.7%). Hardware complications were common but similar across groups, with screw pullout more frequent in ACR. Kaplan-Meier analysis of revision-free survival up to 50 months showed no significant differences among groups (Log-rank, <italic>P</italic> = 0.478), with the earliest reoperations occurring in the Ponte group, followed by the ACR and PSO groups. </sec><sec><title>Conclusions</title> PSO achieved the greatest sagittal correction, while IDO and ACR provided intermediate correction. Although not statistically significant, IDO showed a numerically higher revision-free survival, with the earlier reoperations observed in Ponte, followed by ACR and PSO. These findings suggest a trend toward greater durability with IDO, highlighting the importance of osteotomy selection in maintaining long-term alignment. </sec><sec><title>Clinical Relevance</title> These findings highlight the distinct corrective profiles, safety considerations, and long-term mechanical complication outcomes of four osteotomy techniques, emphasizing their clinical implications for surgical planning and decision-making. </sec><sec><title>Level of Evidence</title> 3. </sec>