TY - JOUR
T1 - The Lumbar Pelvic Angle, the Lumbar Component of the T1 Pelvic Angle, Correlates with HRQOL, PI-LL Mismatch, and it Predicts Global Alignment
AU - Protopsaltis, Themistocles S.
AU - Lafage, Renaud
AU - Smith, Justin S.
AU - Passias, Peter G.
AU - Shaffrey, Christopher I.
AU - Kim, Han Jo
AU - Mundis, Gregory M.
AU - Ames, Christopher P.
AU - Burton, Douglas C.
AU - Bess, Shay
AU - Klineberg, Eric
AU - Hart, Robert A.
AU - Schwab, Frank J.
AU - Lafage, Virginie
PY - 2018/5/15
Y1 - 2018/5/15
N2 - Study Design. Prospective multicenter analysis of adult spinal deformity (ASD) patients. Objective. The aim of this study was to introduce the lumbar pelvic angle (LPA), a novel parameter of spinopelvic alignment. Summary of Background Data. The T1 pelvic angle (TPA), a measure of global spinopelvic alignment, correlates with health-related quality of life (HRQOL), but it may not be measureable on all intraoperative x-rays. In patients with previous interbody fusion at L5-S1, the plane of the S1 endplate can be blurred, creating error in pelvic incidence and lumbar lordosis (PI-LL) measure. The LPA is more readily measured on intraoperative imaging than the TPA. Methods. ASD patients were included with either coronal Cobb angle >20°, sagittal vertical axis (SVA) >5 cm, thoracic kyphosis >60°, or pelvic tilt (PT) >25°. Measures of disability included Oswestry Disability Index (ODI), Scoliosis Research Society (SRS), and Short Form (SF)-36. Baseline and 2-year follow-up radiographic and HRQOL outcomes were evaluated. Linear regressions compared LPA with radiographic parameters and HRQOL. Results. A total of 852 ASD patients (407 operative) were enrolled (mean age 53.7). Baseline LPA correlated with PI-LL (r = 0.79), PT (r = 0.78), TPA (r = 0.82), and SVA (r = 0.61) (all P < 0.001). PI-LL, LPA, and TPA correlated with ODI (r = 0.42/0.29/0.45), SF-36 physical component score (-0.43/-0.28/-0.45) SRS (-0.354/-0.23/-0.37) with all P < 0.001. At 2 years' follow-up, LPA correlated with PI-LL (r = 0.77), PT (r = 0.78), TPA (r = 0.83), and SVA (r = 0.57) (all P < 0.001). Categorizing patients by increasing LPA (<7°; 7°-15°; >15°) revealed progressive increases in all HRQOL, PI-LL (-3.2°/12.7°/32.4°), and TPA (9.7°/20.1°/34.6°) with all P < 0.001. Moderate disability (ODI = 40) corresponded to LPA 10.1°, PI-LL 12.6°, and TPA 20.6°. Mild disability (ODI = 20) corresponded to LPA 7.2°, PI-LL 4.2°, and TPA 14.7°. Conclusion. LPA correlates with TPA, PI-LL, and HRQOL in ASD patients. LPA can be used as an intraoperative tool to gauge correction with a target LPA of <7.2°. LPA predicts global alignment, as it correlates with baseline and 2-year TPA and SVA. Along with the cervical-thoracic pelvic angle and TPA, LPA completes the fan of spinopelvic alignment. Level of Evidence: 3.
AB - Study Design. Prospective multicenter analysis of adult spinal deformity (ASD) patients. Objective. The aim of this study was to introduce the lumbar pelvic angle (LPA), a novel parameter of spinopelvic alignment. Summary of Background Data. The T1 pelvic angle (TPA), a measure of global spinopelvic alignment, correlates with health-related quality of life (HRQOL), but it may not be measureable on all intraoperative x-rays. In patients with previous interbody fusion at L5-S1, the plane of the S1 endplate can be blurred, creating error in pelvic incidence and lumbar lordosis (PI-LL) measure. The LPA is more readily measured on intraoperative imaging than the TPA. Methods. ASD patients were included with either coronal Cobb angle >20°, sagittal vertical axis (SVA) >5 cm, thoracic kyphosis >60°, or pelvic tilt (PT) >25°. Measures of disability included Oswestry Disability Index (ODI), Scoliosis Research Society (SRS), and Short Form (SF)-36. Baseline and 2-year follow-up radiographic and HRQOL outcomes were evaluated. Linear regressions compared LPA with radiographic parameters and HRQOL. Results. A total of 852 ASD patients (407 operative) were enrolled (mean age 53.7). Baseline LPA correlated with PI-LL (r = 0.79), PT (r = 0.78), TPA (r = 0.82), and SVA (r = 0.61) (all P < 0.001). PI-LL, LPA, and TPA correlated with ODI (r = 0.42/0.29/0.45), SF-36 physical component score (-0.43/-0.28/-0.45) SRS (-0.354/-0.23/-0.37) with all P < 0.001. At 2 years' follow-up, LPA correlated with PI-LL (r = 0.77), PT (r = 0.78), TPA (r = 0.83), and SVA (r = 0.57) (all P < 0.001). Categorizing patients by increasing LPA (<7°; 7°-15°; >15°) revealed progressive increases in all HRQOL, PI-LL (-3.2°/12.7°/32.4°), and TPA (9.7°/20.1°/34.6°) with all P < 0.001. Moderate disability (ODI = 40) corresponded to LPA 10.1°, PI-LL 12.6°, and TPA 20.6°. Mild disability (ODI = 20) corresponded to LPA 7.2°, PI-LL 4.2°, and TPA 14.7°. Conclusion. LPA correlates with TPA, PI-LL, and HRQOL in ASD patients. LPA can be used as an intraoperative tool to gauge correction with a target LPA of <7.2°. LPA predicts global alignment, as it correlates with baseline and 2-year TPA and SVA. Along with the cervical-thoracic pelvic angle and TPA, LPA completes the fan of spinopelvic alignment. Level of Evidence: 3.
KW - T1-pelvic angle
KW - adult spinal deformity surgery
KW - global spinopelvic alignment
KW - health-related quality of life
KW - interbody fusion
KW - intraoperative planning
KW - lumbar pelvic angle
KW - patient-reported outcomes
KW - radiographic parameters
KW - sagittal malalignment
KW - thoracolumbar surgery
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U2 - 10.1097/BRS.0000000000002346
DO - 10.1097/BRS.0000000000002346
M3 - Article
C2 - 28742755
AN - SCOPUS:85025828851
SN - 0362-2436
VL - 43
SP - 681
EP - 687
JO - Spine
JF - Spine
IS - 10
ER -