Modified Compact-Contact Pedicle Subtraction Osteotomy: Technique Description and Outcomes in a Retrospective Case Series

Abstract

Background: Pedicle subtraction osteotomy (PSO) is an established technique for correcting fixed sagittal plane deformities (FSPD), but it is associated with substantial blood loss and a risk of pseudarthrosis. This study aims to develop a modified PSO technique to treat FSPD and assess its technical efficacy and safety.

Methods: A retrospective review was conducted on patients with FSPD who underwent the modified PSO technique between 2004 and 2021. Radiographic outcomes were assessed using kyphotic angle and sagittal vertical axis (SVA), while clinical outcomes were evaluated using the visual analog scale (VAS) for back pain and the Oswestry Disability Index (ODI). Postoperative complications were assessed to evaluate the safety of the technique.

Results: Fifty-three patients (54.7% men) with a mean age of 34.5 years were included in the study, with a mean follow-up of 54.8 months. The mean intraoperative blood loss was 466.9 ± 252.9 ml. Postoperatively, the mean kyphotic angle improved significantly from 37.2° to 8.5° (P < 0.0001). At the final follow-up, a mean loss of correction of 6.4° was observed compared with the immediate postoperative measurement. Statistically significant improvements were observed in the SVA, ODI, and VAS between the preoperative and postoperative assessments (P < 0.0001 for all). Postoperative complications occurred in five patients (9.4%), including pseudarthrosis with rod breakage in two patients (3.8%). No intraoperative or early postoperative neurological complications were observed.

Conclusion: The modified compact-contact PSO technique was feasible and demonstrated favorable radiographic and clinical outcomes, with relatively limited estimated blood loss (EBL) in primary procedures and a low rate of pseudarthrosis. Prospective comparative studies are warranted