Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 30;15(1):32002.
doi: 10.1038/s41598-025-18031-9.

Predicting postoperative imbalance in adult spinal deformity staged surgery using predictive thresholds

Xue-Peng Wei #  1   2 , Chen-Wei Yeh #  3 , Erh-Ti Ernest Lin  1 , Hung-Lun Hsieh  1 , Hsien-Te Chen  3 , Yuan-Shun Lo  4   5   6
Affiliations

Predicting postoperative imbalance in adult spinal deformity staged surgery using predictive thresholds

Xue-Peng Wei et al. Sci Rep. .

Abstract

Two-stage surgeries are increasingly used to minimize complications in adult spinal deformity (ASD) correction, yet the specific contributions of lateral lumbar interbody fusion (LLIF) and posterior column osteotomy/posterior spinal fusion (PCO/PSF) remain underexplored. This study evaluates their roles in deformity correction and establishes predictive thresholds for optimizing surgical planning. A total of 151 ASD patients (mean age 69.5 years) underwent staged LLIF and PCO/PSF surgeries one week apart. Radiographic parameters were analyzed preoperatively (Pre-), post- 1st LLIF (M-), post- 2nd PCO/PSF (Post-), and at two-year follow-up (F-). Correction rates were 80.9% for PI-LL mismatch (35.5% LLIF, 64.5% PCO/PSF), 40.5% for pelvic tilt (39.4% LLIF, 60.6% PCO/PSF), and 69.1% for C7 SVA (45.7% LLIF, 54.3% PCO/PSF). Coronal correction of the Cobb angle reached 76.7% (33.1% LLIF, 66.9% PCO/PSF). Significant ODI and SRS-22 score improvements were noted at two years. Predictive thresholds for imbalance were M-SVA 75.3 mm, M-PI-LL 32.5°, and M-PT 35.5°. The 2nd PCO/PSF contributes more to correction, and predictive thresholds aid surgical planning, reducing postoperative imbalance for better outcomes.

Keywords: Adult spinal deformity (ASD); Imbalance; Lateral lumbar interbody fusion (LLIF); Posterior column osteotomy (PCO); Stage surgery.

PubMed Disclaimer

Conflict of interest statement

Declarations. Competing interests: The authors declare no competing interests. Ethical approval: The study protocol was approved by the Institutional Review Board of our hospital (Approval Number CMUH111-REC1-128) and performed in accordance with Declaration of Helsinki. Informed consent was obtained from all participants.

Figures

Fig. 1
Fig. 1
Schema describing the correction in the two-stage surgery in ASD. (a) preoperative to the 1st stage LLIF surgery (Pre); (b) postoperative following the 1st stage LLIF surgery (M); (c) postoperative following the 2nd stage PCO/PSF surgery (Post); LLIF lateral lumbar interbody fusion, PCO posterior column osteotomy, PSF posterior spinal fusion.
Fig. 2
Fig. 2
Illustration of measurements of spinal and pelvic parameters in sagittal and coronal radiograph, including TK: thoracic kyphosis; LL: lumbar lordosis; TPA: T1 pelvic angle; PI: pelvic incidence; PT: pelvic tilt; SS: sacral slope; C7 SVA: C7 sagittal vertical axis; TCC: total coronal Cobb angle; UCC: upper coronal Cobb angle; LCC: lower coronal Cobb angle; C7PL-CSVL: C7 coronal plumb line to central sacral vertical axis; AVT: apical vertebra translation.
Fig. 3
Fig. 3
Flow diagram illustrating patient recruitment in the study.
Fig. 4
Fig. 4
Predictive thresholds for postoperative imbalance based on C7 SVA < 50 mm as the threshold.
Fig. 5
Fig. 5
Predictive thresholds for postoperative imbalance based on PI-LL ≤ 10° as the Threshold.
Fig. 6
Fig. 6
Predictive thresholds for postoperative imbalance based on PT < 25° as the threshold.
Fig. 7
Fig. 7
Immediate postoperative sagittal or coronal imbalance and compensatory self-correction.
See this image and copyright information in PMC

References

    1. Takemoto, M. et al. Sagittal malalignment has a significant association with postoperative leg pain in adult spinal deformity patients. Eur. Spine J.25, 2868–2875 (2016). - PubMed
    1. Häkkinen, A. et al. Spinopelvic changes based on the simplified SRS-Schwab adult spinal deformity classification: relationships with disability and health-related quality of life in adult patients with prolonged degenerative spinal disorders. Spine42, E304–E310 (2017). - PubMed
    1. Li, G. et al. Adult scoliosis in patients over sixty-five years of age: outcomes of operative versus nonoperative treatment at a minimum two-year follow-up. Spine (Phila Pa. 1976). 34, 2165–2170 (2009). - PubMed
    1. Smith, J. S. et al. Risk-benefit assessment of surgery for adult scoliosis: an analysis based on patient age. Spine (Phila Pa. 1976). 36, 817–824 (2011). - PubMed
    1. Bridwell, K. H. et al. Does treatment (nonoperative and operative) improve the two-year quality of life in patients with adult symptomatic lumbar scoliosis: a prospective multicenter evidence-based medicine study. Spine (Phila Pa. 1976). 34, 2171–2178 (2009). - PubMed