Partial Pedicle Subtraction Osteotomy as an Alternative Option for Spinal Sagittal Deformity Correction

Abstract

A retrospective study. To describe the technique of a partial pedicle subtraction osteotomy (PPSO) and to report on the clinical and radiological outcomes. Numerous corrective osteotomy techniques have been reported. Until now, there has been no reported method that can achieve a correction angle between those of the Smith-Petersen osteotomy and pedicle subtraction osteotomy as a posterior closing osteotomy that can be safely performed on the thoracic spine. A total of 38 patients aged between 31 and 72 years, who underwent PPSO for spinal sagittal deformity correction were enrolled in this study. The mean postoperative follow-up period was 30.1 months (range, 24-36 mo). The assessments included the Oswestry Disability Index scores, immediate postoperative and 2-year postoperative correction angles, correction loss, pseudoarthrosis, and complications. There were 6 patients who underwent PPSO alone and 32 patients who underwent PPSO combined with at least one other surgical procedure (PSO in 16 patients, anterior lumbar interbody fusion in 12 patients, and Smith-Petersen osteotomy in 4 patients). The level of the osteotomy was T10 in 6 patients, T11 in 15 patients, T12 in 10 patients, 1 in 4 patients, L2 in 2 patients, and L3 in 1 patient. There were significant improvements in the overall Oswestry Disability Index scores (P = 0.001). The mean postoperative correction angle immediately after the PPSO was 18.8° (range, 12.4°-26.1°) and the mean postoperative correction angle at 2 years was 18.4° (range, 11.9°-25.7°). There was no significant loss of correction found during the 2-year follow-up. There was also no pseudoarthrosis or neurological complications. PPSO had resulted in intermediate correction rates between those of Smith-Petersen osteotomy and PSO. PPSO is considered to be a safe and reliable procedure for patients with spinal sagittal deformities even at the thoracic spine level. 4.