The ISSG-AO Complication Intervention Score, but Not Major/Minor Designation, is Correlated With Length of Stay Following Adult Spinal Deformity Surgery

Joseph B Wick; Andrew Blandino; Justin S Smith; Breton G Line; Virginie Lafage; Renaud Lafage; Han Jo Kim; Peter G Passias; Jeffrey L Gum; Khaled M Kebaish; Robert K Eastlack; Alan Daniels; Gregory Mundis; Richard Hostin; Themistocles Protopsaltis; D Kojo Hamilton; Michael P Kelly; Munish Gupta; Robert A Hart; Frank J Schwab; Douglas C Burton; Christopher P Ames; Lawrence G Lenke; Christopher I Shaffrey; Shay Bess; Eric Klineberg; International Spine Study Group

doi:10.1177/21925682231202782

The ISSG-AO Complication Intervention Score, but Not Major/Minor Designation, is Correlated With Length of Stay Following Adult Spinal Deformity Surgery

Global Spine J. 2023 Sep 19:21925682231202782. doi: 10.1177/21925682231202782. Online ahead of print.

Authors

Joseph B Wick¹, Andrew Blandino¹, Justin S Smith², Breton G Line³, Virginie Lafage⁴, Renaud Lafage⁵, Han Jo Kim⁵, Peter G Passias⁶, Jeffrey L Gum⁷, Khaled M Kebaish⁸, Robert K Eastlack⁹, Alan Daniels¹⁰, Gregory Mundis⁹, Richard Hostin¹¹, Themistocles Protopsaltis⁶, D Kojo Hamilton¹², Michael P Kelly¹³, Munish Gupta¹⁴, Robert A Hart¹⁵, Frank J Schwab⁴, Douglas C Burton¹⁶, Christopher P Ames¹⁷, Lawrence G Lenke¹⁸, Christopher I Shaffrey¹⁹, Shay Bess³, Eric Klineberg²⁰; International Spine Study Group

Affiliations

¹ Department of Orthopedic Surgery, University of California, Davis, Sacramento, CA, USA.
² Department of Neurosurgery, Medical Center, University of Virginia, Charlottesville, VA, USA.
³ Department of Orthopedic Surgery, Denver International Spine Center, Denver, CO, USA.
⁴ Department of Orthopedic Surgery, Northwell Health, Lenox Hill Hospital, New York, NY, USA.
⁵ Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY, USA.
⁶ Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, New York, NY, USA.
⁷ Department of Orthopedic Surgery, Norton Leatherman Spine Center, Louisville, KY, USA.
⁸ Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD, USA.
⁹ Department of Orthopedics, San Diego Center for Spinal Disorders, La Jolla, CA, USA.
¹⁰ Department of Orthopedics, Brown University, Providence, RI, USA.
¹¹ Department of Orthopedic Surgery, Baylor Scoliosis Center, Dallas, TX, USA.
¹² Department of Neurosurgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
¹³ Department of Orthopedic Surgery, Rady Children's Hospital, San Diego, CA.
¹⁴ Department of Orthopedic Surgery, Washington University in St. Louis, St. Louis, MO, USA.
¹⁵ Department of Orthopedic Surgery, Swedish Neuroscience Institute, Seattle, WA, USA.
¹⁶ Department of Orthopedic Surgery, University of Kansas Medical Center, Kansas City, KS, USA.
¹⁷ Department of Neurosurgery, University of California, San Francisco, San Francisco, CA, USA.
¹⁸ Department of Orthopedic Surgery, Columbia University, New York, NY, USA.
¹⁹ Department of Neurosurgery, Duke University Hospital, Durham, NC, USA.
²⁰ Department of Orthopedic Surgery, University of Texas, Houston, TX, USA.

PMID: 37725904
DOI: 10.1177/21925682231202782

Abstract

Study design: Retrospective review.

Objectives: The International Spine Study Group-AO (ISSG-AO) Adult Spinal Deformity (ASD) Complication Classification System was developed to improve classification, reporting, and study of complications among patients undergoing ASD surgery. The ISSG-AO system classifies interventions to address complications by level of invasiveness: grade zero (none); grade 1, mild (e.g., medication change); grade 2, moderate (e.g., ICU admission); grade 3, severe (e.g., reoperation related to surgery of interest). To evaluate the efficacy of the ISSG-AO ASD Complication Classification System, we aimed to compare correlations between postoperative length of stay (LOS) and complication severity as classified by the ISSG-AO ASD and traditional major/minor complication classification systems.

Methods: Patients age ≥18 in a multicenter ASD database who sustained in-hospital complications were identified. Complications were classified with the major/minor and ISSG-AO systems and correlated with LOS using an ensemble-based machine learning algorithm (conditional random forest) and a generalized linear mixed model.

Results: 490 patients at 19 sites were included. 64.9% of complications were major, and 35.1% were minor. By ISSG-AO classification, 20.4%, 66.1%, 6.7%, and 6.7% were grades 0-3, respectively. ISSG-AO complication grading demonstrated significant correlation with LOS, whereas major/minor complication classification demonstrated inverse correlation with LOS. In conditional random forest analysis, ISSG-AO classification had the greatest relative importance when assessing correlations across multiple variables with LOS.

Conclusions: The ISSG-AO system may help identify specific complications associated with prolonged LOS. Targeted interventions to avoid or reduce these complications may improve ASD surgical quality and resource utilization.

Keywords: adult spinal deformity; classification; complications; deformity; degenerative; grading; length of stay; lumbar; major; minor; neurologic; scoliosis; spine; thoracic.