The T4-L1-Hip Axis: Defining a Normal Sagittal Spinal Alignment.
Spine (Phila Pa 1976)
; 47(19): 1399-1406, 2022 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-35867583
ABSTRACT
STUDY DESIGN:
This is a cross-sectional cohort.OBJECTIVE:
The aim was to describe sagittal plane alignment and balance in a multinational cohort of nondegenerated, asymptomatic adults. SUMMARY OF BACKGROUND DATA Current sagittal alignment targets were developed using correlations between radiographic and quality-of-life measures in spinal deformity patients, rather than disease-free samples leading to relatively poor accounting for variance within a population. MATERIALS ANDMETHODS:
Sagittal balance was defined using vertebral body tilt and spinopelvic alignment was defined as the vertebral pelvic angles from C2 to L5 (vertebral pelvic angle=vertebral tilt+pelvic tilt). Associations with pelvic incidence (PI) were assessed using linear regression. Multivariable linear regression was used to estimate a normal L1-S1 lordosis, adjusting for PI and the L1 pelvic angle (L1PA). Correlation between the L1 and T4 pelvic angles was assessed to define a normal thoracic alignment conditioned on lumbar alignment.RESULTS:
Among 320 volunteers from 4 continents, median age was 37% and 60% were female. C2 tilt was independent of PI with minimal variation. PI was inadequate for estimating a normal lumbar lordosis (L1-S1, r2 =0.3), but was strongly associated with the lumbar pelvic angles (L1PA, r2 =0.58). Defining lumbar lordosis as a function of PI and L1PA resulted in high explained variance ( R2 =0.74) and the T4 pelvic angle had near perfect correlation with the L1PA ( r =0.9).CONCLUSIONS:
We defined normal sagittal balance and spinopelvic alignment in a disease-free international volunteer cohort. Four parameters are either fixed or directly modifiable in surgery and can define a normal thoracic and lumbar alignment the L1-S1 lordosis defined as a function of PI and the L1PA; and the T4 pelvic angle is nearly equivalent to the L1PA, aligning the T4-L1-hip axis.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Lordose
Tipo de estudo:
Diagnostic_studies
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Observational_studies
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Prevalence_studies
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Risk_factors_studies
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Spine (Phila Pa 1976)
Ano de publicação:
2022
Tipo de documento:
Article