JBJS - 2026-04-21 - Journal Article
High-Grade 3-Column Osteotomies Are Not Interchangeable: Schwab-Grade-III PSO Versus Schwab-Grade-V VCR in Treating Severe Kyphoscoliosis with an Average 9-Year Follow-up.
Zhang Y, Wang S, Bai Z, Zhang Y, Niu X, Liu S, Han Y, Zhuang Q, Zhang J
Topics
Key Takeaway
VCR achieves superior 3-plane correction versus PSO (65.5% vs 56.9% major curve, 68.1% vs 61.5% segmental kyphosis, 48.5% vs 34.4% apical rotation) but carries a significantly higher neurological complication rate (15.5% vs 8.2%) and each additional degree of VCR correction confers a 1.6% increased complication risk.
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Summary
This single-center retrospective study compared Schwab Grade III PSO (n=85) versus Schwab Grade V VCR (n=84) in 169 young patients (mean age 22) with severe kyphoscoliosis, evaluating radiographic correction, SRS-22 outcomes, IOM changes, and complications at mean 9-year follow-up. VCR provided statistically superior coronal, sagittal, and axial correction across all three planes (p≤0.03 for each). However, VCR carried a significantly higher neurological complication rate (13/84 vs 7/85, p=0.038) and overall complication rate (43/84 vs 29/85, p=0.008), with each degree of correction gained via VCR associated with a 1.6% incremental complication risk (OR=1.016, p=0.045).
Key Limitation
Non-randomized osteotomy assignment means the VCR group likely harbored more severe baseline deformity, making it impossible to determine whether the higher complication rate reflects the procedure itself or the underlying deformity complexity.
Original Abstract
BACKGROUND
Pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR) are powerful techniques for correcting severe spinal deformities. Although PSO has been proposed as a viable alternative to VCR, their comparative efficacies and safety profiles require further elucidation.
METHODS
This single-center retrospective study analyzed 169 patients (mean age, 22 years; 84 male; 169 ethnic Chinese) with severe kyphoscoliosis who underwent primary corrective surgery via PSO (n = 85) or VCR (n = 84). Radiographic parameters, surgical data, intraoperative neuromonitoring (IOM) changes, Scoliosis Research Society (SRS)-22 scores, and complications were compared between groups.
RESULTS
Both techniques significantly improved all radiographic parameters and SRS-22 scores (p < 0.001). The VCR group demonstrated superior correction of the major curve (65.5% versus 56.9%, p = 0.003), segmental kyphosis (68.1% versus 61.5%, p = 0.03), and apical vertebral rotation (48.5% versus 34.4%, p = 0.001). At the critical osteotomy stage, 105 (62.1%) of 169 patients experienced IOM signal decline. The neurological complications rate was significantly higher in the VCR group (13 of 84 versus 7 of 85, p = 0.038), as was the overall complication rate (43 of 84 versus 29 of 85, p = 0.008). Each 1° increase in correction achieved with VCR was associated with a 1.6% higher risk of complications (OR = 1.016, p = 0.045).
CONCLUSIONS
Although both PSO and VCR were highly effective for major deformity correction, VCR provided a greater magnitude of correction in the coronal, sagittal, and axial planes. However, this advantage was counterbalanced by a significantly higher risk of complications, including neurological deficits. Despite the frequent reversibility of IOM signal declines, VCR retained a higher risk profile due to its higher overall complication rate.
LEVEL OF EVIDENCE
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.