Normal values for sagittal spinal alignment: a study of Brazilian subjects

Abstract

OBJECTIVES:The purpose of this study is to investigate the normal values of and chain of correlations between spinopelvic parameters in a Brazilian population.METHODS:This is a prospective observational study including asymptomatic adult subjects who had full spinal radiographs performed. The subjects were stratified by age into 3 groups (18-39 years old, 40-59 years old, and >60 years old), and radiographic parameters were compared across age groups and gender using ANOVA and Student's t-test, respectively. The relationships between various radiographic parameters were evaluated with Pearson correlation coefficients.RESULTS:One hundred and thirty asymptomatic volunteers (mean age, 48 years) met the inclusion criteria. The mean sagittal parameters in a normal Brazilian population were as follows: lumbar lordosis (LL) of 56.8°, pelvic tilt (PT) of 12.4°, pelvic incidence (PI) of 49.4°, PI–LL of -7.4°, T1 pelvic angle (TPA) of 8°, sagittal vertical axis (SVA) of -0.54 cm and T1 slope of 25.2°. Subjects ≥60 years old had significantly higher values of SVA (p=0.024) and TPA (p=0.009) than the two younger age groups. The TPA was significantly correlated with the following spinopelvic parameters: LL (r=-0.172, p=0.005), PT (r=0.776, p<0.001), PI (r=0.508, p<0.001), PI–LL (r=0.717, p<0.001), SVA (r=0.409, p<0.001) and T1 slope (r=0.172, p=0.050).CONCLUSION:This study demonstrated significant physiologic trunk inclination with increasing age. The TPA, an angular parameter of global spinal alignment, presented a chain of correlations with different spinal segments.

Relationship of the sacral slope with early gait derangements in robust older women

“…The characteristics of the sample are described in Table 1. In comparison to what has been reported for Brazilians older than 60 years [26], we observed an increase in the following pelvic angles mean ± SD: Pelvic Incidence (50.9°± 6.6°vs. 57.9°± 11.5°), Pelvic Tilt (13.8 ± 5°vs.…”

“…In our sample of older women, without gait complaints, there was an increase in the expected mean value of Pelvic Incidence and Sacral Slope [26]. Notwithstanding, a Sacral Slope between 35°and 45°, as obtained in our sample, is described as representative of a healthy balanced spine [44].…”

“…Sacral Slope was defined as the angle subtended by a horizontal reference line and the sacral endplate line. The reported mean reference values for Brazilians, older than 60 years were: Pelvic Incidence angle of 50.9°± 6.6°, Sacral Slope of 37.4°± 5.1°, and Pelvic Tilt of 13.8°± 5° [26].…”

Effect of lumbar laminectomy on spinal sagittal alignment: a systematic review

“…A correlation has been found between the shape and orientation of the pelvis and the morphology of sagittal spinal curvatures in asymptomatic persons [10,11]. Greater positive SSPA has been found in asymptomatic elderly people [8,9,12]. Decreased LL has been shown to have a strong correlation with low back pain [13].…”

“…Since Legaye and Duval-Beaupère introduced pelvic incidence (PI) as a key parameter regulating sagittal spinal balance [7], sagittal balance and its correlation with the results of spine surgery have been widely studied. PI is considered a constant parameter with no significant change with age, while thoracic kyphosis (TK) increases and lumbar lordosis (LL) decreases with age [8,9].…”