Sacro-femoral-pubic angle: a coronal parameter to estimate pelvic tilt

Abstract

The pelvic tilt is an essential measure in the context of radiographic evaluation of spinal deformity and malalignment. Given the routinely excellent visibility of coronal films this study established the SFP as a coronal parameter which can reliably estimate pelvic tilt. The high correlation and predictive ability of the SFP angle should prompt further study and clinical application when lateral radiographs do not permit assessment of pelvic parameters.

Can Pelvic Tilt be Predicated by the Sacrofemoral-Pubic Angel in Patients With Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis?

“…13 Similarly, in the current study, the mean PT and SFP angle were 32.9 ° ± 13.1 ° and 47.5 ° ± 12.4 ° , respectively, and PT was strongly correlated with the SFP angle ( r = 0.852; P < 0.001). In addition, PT, SFP angle, and GK demonstrated moderate correlation in this study.…”

“…The SFP angle was based on the landmarks of the pelvic inlet, so it was affected in the same manner as the coronal projection of the pelvic inlet by the pelvic retroversion ( Figure 4A-D ). Notably, the correlation between PT and 13 The difference between the 2 formulas may be attributed to 2 reasons. First, adults with different ethnicity (Caucasian vs .…”

“…On coronal view, the SFP angle was defi ned as the angle between line a and b (line a connected the midpoint of the upper sacral endplate to the center of one acetabula, and line b linked the center of one acetabula to the upper midpoint of the pubic symphysis) ( Figure 2A ). 13 The SFP angle was calculated as the mean value of left and right SFP angles. On lateral fi lm, PT was measured as the angle between the vertical line and the line through the midpoint of the sacral plate to the axis of the femoral head ( Figure 2B ).…”

“…11 , 12 This may lead to poor visualization of the femoral heads on sagittal radiographs, limiting the accuracy of PT measurements ( Figure 1A, B ). Of note, in a recent study, Blondel et al 13 established a coronal plane pelvic parameter (sacrofemoralpubic [SFP] angle) for evaluating PT when the measurement of PT was impossible on lateral radiographs in adult patients with scoliosis. To the best of our knowledge, using the SFP angle to predict PT has not been studied in patients with AS.…”

Epidemiology and associated radiographic spinopelvic parameters of symptomatic degenerative lumbar scoliosis: are radiographic spinopelvic parameters associated with the presence of symptoms or decreased quality of life in degenerative lumbar scoliosis?

“…However, measuring the PT is often difficult because of the difficulty of identifying the acetabuli and femoral head on plain lateral X-rays. Considering this issue, Blondel et al [18] demonstrated that the SFP, as easily measured on anteroposterior X-rays, is highly correlated with the PT and concluded that the SFP can be used as a coronal parameter to estimate the PT when lateral pelvic X-rays do not permit assessments of the PT. In the current study, we performed measurements of the SFP as an alternative to measurements of the PT due to difficulty in identifying the acetabuli and femoral head on plain lateral X-rays in many subjects.…”