Pelvic Rotation Parameters Related to In-Brace Correction in Patients with Idiopathic Scoliosis

Abstract

BACKGROUND: To identify the pelvic parameters affecting in-brace correction (IBC) in patients with idiopathic scoliosis (IS). METHODS: Patients with IS receiving Chêneau brace treatment in our scoliosis center from January 2019 to November 2019 were retrospectively analyzed. Pelvic rotation parameters, including Pelvic incidence (PI), Sacral slope (SS), pelvic tilt (PT), L/R ratio, were collected. Other radiographic data, such as Risser sign, coronal and sagittal balance, curve location, kyphosis, lordosis of each patient was also recorded to analyze their correlations with IBC. Correlation analyses were performed to identify the classified variables influencing IBC. The principal component analysis was used to extract common factors of radiographic parameters to eliminate interaction effects. The linear regression equation was established using principal components, the variables influencing IBC were identified.RESULTS: A cohort of 44 patients with IS (36 girls and 8 boys) were included in the present study. The mean IBC was 49.87% (range, 3%∽100%). IBC of lumbar IS was negatively correlated with apical rotate factor (ARF, B=-0.385), mainly consisted of pelvic coronal plane rotation (PCPR, 0.449), cobb angle (CA,0.575), apical vertebral rotation (AVR, 0.918), and pelvic rotate factor (PRF, B=-0.387), mainly consisted of PT (0.861), PI (0.728), PCPR (-0.570). The regression equation of lumbar IS had statistical significance (F=6.500, P=0.005，R2=0.317). Whereas statistically significance was not found in the regression equation of thoracic IS (F=2.913, P=0.106). The remaining parameters were not related to IBC.CONCLUSIONS: For lumbar IS, ARF and PRF have negative effects on IBC, Coronal and sagittal rotation of the pelvis is related to IBC.

Predictive Factors on Initial in-brace Correction in Idiopathic Scoliosis

“…The literature search in the databases yielded 4562 studies after removal of duplicates (Figure 1). Finally, 28 studies fulfilled the inclusion criteria and were included in this systematic review 10–37 . An overview of the included studies is presented in Table 3.…”

“…Insufficient evidence was found for increased pre-brace major Cobb angle, rib vertebral angle difference, rib vertebral angle-convex side, rib vertebral angle-concave side, lumbar lordosis factor, coronal balance factor, vertical balance factor, and pelvic symmetry factor as influencing factors for initial in-brace correction. 13,25,26,27,29,37 There is also insufficient evidence for higher Risser stage, curve apex <T8, increased lumbopelvic ratio, coronal deformity angular ratio, apical rotate factor, pelvic rotate factors, and spinal coronal or sagittal imbalance as predictive factors for initial in-brace correction. 20,25,26,27,29,37 Other Reported Factors Insufficient evidence was found for age, sex, height, weight, menarche status, and BMI as predictive factors for initial inbrace correction.…”

“…13,25,26,27,29,37 There is also insufficient evidence for higher Risser stage, curve apex <T8, increased lumbopelvic ratio, coronal deformity angular ratio, apical rotate factor, pelvic rotate factors, and spinal coronal or sagittal imbalance as predictive factors for initial in-brace correction. 20,25,26,27,29,37 Other Reported Factors Insufficient evidence was found for age, sex, height, weight, menarche status, and BMI as predictive factors for initial inbrace correction. 14,26,27,29 A high-quality study discovered that brace adjustment of a Milwaukee brace twice per week combined with group exercise under supervision of a skilled physiotherapist for 11 weeks resulted in significantly better initial in-brace Cobb angle curve correction, compared to a routine protocol in the control group (P ¼ 0.04).…”