Predictive Model for Cervical Alignment and Malalignment Following Surgical Correction of Adult Spinal Deformity

International Spine Study Group (ISSG)

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

STUDY DESIGN.: Retrospective review of prospective multicenter database. OBJECTIVE.: Use predictive modeling to identify patient characteristics, radiographic, and surgical variables that predict reaching an outcome threshold of sub-optimal cervical alignment following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA.: Cervical deformity (CD) after ASD correction has been defined with the following criteria: T1S-CL>20°, C2-C7 SVA>40?mm, and/or C2-C7 kyphosis>10°. While studies have analyzed CD predictors, few have defined and identified predictors of optimal cervical alignment following thoracolumbar surgery. METHODS.: Inclusion criteria were surgical ASD patients with baseline and 2-year follow-up. Post-operative cervical alignment (CA) and malalignment (nonCA) at 2-years was defined with the following radiographic criteria: 0°≤T1S-CL≤20°, 0mm≤C2-C7 SVA≤40?mm, or C2-C7 lordosis>0°. Three thresholds classifying malalignment were defined: (T1) missing 1 criterion, (T2) missing 2 criteria, (T3) missing 3 criteria. Multivariable logistic stepwise regression models with bootstrap resampling procedure were performed for demographic, surgical, and radiographic variables. The model was validated with ROC and AUC. RESULTS.: 225 surgical ASD patients were included. At 2-years 208 patients (92.4%) were grouped as CA in T3, while 17 (7.6%) were nonCA. Patients were similar in age (CA: 56.10 vs. nonCA: 55.78 years, p?=?0.150), BMI (CA: 26.93 vs. nonCA: 26.94?kg/m, p?=?0.716), and gender (CA: 76.5% vs. nonCA: 87.0%, p?=?0.194). The final predictive model included C2 slope, C2-T3 CL, T1S-CL, C2-C7 CL, Pelvic Tilt, C2-S1 SVA, PI-LL, and SPO number. In this model (AUC 89.22% [97.49%–80.96%]), the following variables were identified as predictors of nonCA: increased SPO use (OR: 1.336, p?=?0.017), and C2-T3 angle (OR: 1.048, p?=?0.005). CONCLUSIONS.: This study created a statistical model that predicts poor 2-year post-operative cervical malalignment in ASD patients. T3 (patients not meeting all 3 alignment criteria) was the most effective threshold for modeling nonCA, and included increased baseline C2-T3 angle and increased Smith-Peterson osteotomies during index.Level of Evidence: 3

Original languageEnglish (US)
JournalSpine
DOIs
StateAccepted/In press - Apr 19 2016

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Area Under Curve
Lordosis
Kyphosis
Statistical Models
Osteotomy
Logistic Models
Demography
Databases

ASJC Scopus subject areas

  • Medicine(all)
  • Orthopedics and Sports Medicine
  • Clinical Neurology

Cite this

Predictive Model for Cervical Alignment and Malalignment Following Surgical Correction of Adult Spinal Deformity. / International Spine Study Group (ISSG).

In: Spine, 19.04.2016.

Research output: Contribution to journalArticle

@article{cd1e773a208a477c96e6881f4c49a0c2,
title = "Predictive Model for Cervical Alignment and Malalignment Following Surgical Correction of Adult Spinal Deformity",
abstract = "STUDY DESIGN.: Retrospective review of prospective multicenter database. OBJECTIVE.: Use predictive modeling to identify patient characteristics, radiographic, and surgical variables that predict reaching an outcome threshold of sub-optimal cervical alignment following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA.: Cervical deformity (CD) after ASD correction has been defined with the following criteria: T1S-CL>20°, C2-C7 SVA>40?mm, and/or C2-C7 kyphosis>10°. While studies have analyzed CD predictors, few have defined and identified predictors of optimal cervical alignment following thoracolumbar surgery. METHODS.: Inclusion criteria were surgical ASD patients with baseline and 2-year follow-up. Post-operative cervical alignment (CA) and malalignment (nonCA) at 2-years was defined with the following radiographic criteria: 0°≤T1S-CL≤20°, 0mm≤C2-C7 SVA≤40?mm, or C2-C7 lordosis>0°. Three thresholds classifying malalignment were defined: (T1) missing 1 criterion, (T2) missing 2 criteria, (T3) missing 3 criteria. Multivariable logistic stepwise regression models with bootstrap resampling procedure were performed for demographic, surgical, and radiographic variables. The model was validated with ROC and AUC. RESULTS.: 225 surgical ASD patients were included. At 2-years 208 patients (92.4{\%}) were grouped as CA in T3, while 17 (7.6{\%}) were nonCA. Patients were similar in age (CA: 56.10 vs. nonCA: 55.78 years, p?=?0.150), BMI (CA: 26.93 vs. nonCA: 26.94?kg/m, p?=?0.716), and gender (CA: 76.5{\%} vs. nonCA: 87.0{\%}, p?=?0.194). The final predictive model included C2 slope, C2-T3 CL, T1S-CL, C2-C7 CL, Pelvic Tilt, C2-S1 SVA, PI-LL, and SPO number. In this model (AUC 89.22{\%} [97.49{\%}–80.96{\%}]), the following variables were identified as predictors of nonCA: increased SPO use (OR: 1.336, p?=?0.017), and C2-T3 angle (OR: 1.048, p?=?0.005). CONCLUSIONS.: This study created a statistical model that predicts poor 2-year post-operative cervical malalignment in ASD patients. T3 (patients not meeting all 3 alignment criteria) was the most effective threshold for modeling nonCA, and included increased baseline C2-T3 angle and increased Smith-Peterson osteotomies during index.Level of Evidence: 3",
author = "{International Spine Study Group (ISSG)} and Passias, {Peter G.} and Cheongeun Oh and Jalai, {Cyrus M.} and Nancy Worley and Renaud Lafage and Scheer, {Justin K.} and Klineberg, {Eric O.} and Robert Hart and Kim, {Han Jo} and Smith, {Justin S.} and Virginie Lafage and Ames, {Christopher P.}",
year = "2016",
month = "4",
day = "19",
doi = "10.1097/BRS.0000000000001640",
language = "English (US)",
journal = "Spine",
issn = "0362-2436",
publisher = "Lippincott Williams and Wilkins",

}

TY - JOUR

T1 - Predictive Model for Cervical Alignment and Malalignment Following Surgical Correction of Adult Spinal Deformity

AU - International Spine Study Group (ISSG)

AU - Passias, Peter G.

AU - Oh, Cheongeun

AU - Jalai, Cyrus M.

AU - Worley, Nancy

AU - Lafage, Renaud

AU - Scheer, Justin K.

AU - Klineberg, Eric O.

AU - Hart, Robert

AU - Kim, Han Jo

AU - Smith, Justin S.

AU - Lafage, Virginie

AU - Ames, Christopher P.

PY - 2016/4/19

Y1 - 2016/4/19

N2 - STUDY DESIGN.: Retrospective review of prospective multicenter database. OBJECTIVE.: Use predictive modeling to identify patient characteristics, radiographic, and surgical variables that predict reaching an outcome threshold of sub-optimal cervical alignment following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA.: Cervical deformity (CD) after ASD correction has been defined with the following criteria: T1S-CL>20°, C2-C7 SVA>40?mm, and/or C2-C7 kyphosis>10°. While studies have analyzed CD predictors, few have defined and identified predictors of optimal cervical alignment following thoracolumbar surgery. METHODS.: Inclusion criteria were surgical ASD patients with baseline and 2-year follow-up. Post-operative cervical alignment (CA) and malalignment (nonCA) at 2-years was defined with the following radiographic criteria: 0°≤T1S-CL≤20°, 0mm≤C2-C7 SVA≤40?mm, or C2-C7 lordosis>0°. Three thresholds classifying malalignment were defined: (T1) missing 1 criterion, (T2) missing 2 criteria, (T3) missing 3 criteria. Multivariable logistic stepwise regression models with bootstrap resampling procedure were performed for demographic, surgical, and radiographic variables. The model was validated with ROC and AUC. RESULTS.: 225 surgical ASD patients were included. At 2-years 208 patients (92.4%) were grouped as CA in T3, while 17 (7.6%) were nonCA. Patients were similar in age (CA: 56.10 vs. nonCA: 55.78 years, p?=?0.150), BMI (CA: 26.93 vs. nonCA: 26.94?kg/m, p?=?0.716), and gender (CA: 76.5% vs. nonCA: 87.0%, p?=?0.194). The final predictive model included C2 slope, C2-T3 CL, T1S-CL, C2-C7 CL, Pelvic Tilt, C2-S1 SVA, PI-LL, and SPO number. In this model (AUC 89.22% [97.49%–80.96%]), the following variables were identified as predictors of nonCA: increased SPO use (OR: 1.336, p?=?0.017), and C2-T3 angle (OR: 1.048, p?=?0.005). CONCLUSIONS.: This study created a statistical model that predicts poor 2-year post-operative cervical malalignment in ASD patients. T3 (patients not meeting all 3 alignment criteria) was the most effective threshold for modeling nonCA, and included increased baseline C2-T3 angle and increased Smith-Peterson osteotomies during index.Level of Evidence: 3

AB - STUDY DESIGN.: Retrospective review of prospective multicenter database. OBJECTIVE.: Use predictive modeling to identify patient characteristics, radiographic, and surgical variables that predict reaching an outcome threshold of sub-optimal cervical alignment following adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA.: Cervical deformity (CD) after ASD correction has been defined with the following criteria: T1S-CL>20°, C2-C7 SVA>40?mm, and/or C2-C7 kyphosis>10°. While studies have analyzed CD predictors, few have defined and identified predictors of optimal cervical alignment following thoracolumbar surgery. METHODS.: Inclusion criteria were surgical ASD patients with baseline and 2-year follow-up. Post-operative cervical alignment (CA) and malalignment (nonCA) at 2-years was defined with the following radiographic criteria: 0°≤T1S-CL≤20°, 0mm≤C2-C7 SVA≤40?mm, or C2-C7 lordosis>0°. Three thresholds classifying malalignment were defined: (T1) missing 1 criterion, (T2) missing 2 criteria, (T3) missing 3 criteria. Multivariable logistic stepwise regression models with bootstrap resampling procedure were performed for demographic, surgical, and radiographic variables. The model was validated with ROC and AUC. RESULTS.: 225 surgical ASD patients were included. At 2-years 208 patients (92.4%) were grouped as CA in T3, while 17 (7.6%) were nonCA. Patients were similar in age (CA: 56.10 vs. nonCA: 55.78 years, p?=?0.150), BMI (CA: 26.93 vs. nonCA: 26.94?kg/m, p?=?0.716), and gender (CA: 76.5% vs. nonCA: 87.0%, p?=?0.194). The final predictive model included C2 slope, C2-T3 CL, T1S-CL, C2-C7 CL, Pelvic Tilt, C2-S1 SVA, PI-LL, and SPO number. In this model (AUC 89.22% [97.49%–80.96%]), the following variables were identified as predictors of nonCA: increased SPO use (OR: 1.336, p?=?0.017), and C2-T3 angle (OR: 1.048, p?=?0.005). CONCLUSIONS.: This study created a statistical model that predicts poor 2-year post-operative cervical malalignment in ASD patients. T3 (patients not meeting all 3 alignment criteria) was the most effective threshold for modeling nonCA, and included increased baseline C2-T3 angle and increased Smith-Peterson osteotomies during index.Level of Evidence: 3

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