Thoracic kyphosis assessment in postmenopausal women: an examination of the Flexicurve method in comparison to radiological methods

Reliability of the Smartphone Application Inclinometer and Flexicurve in Measuring Thoracic Kyphosis

INTRODUCTION

This study examined the inter- and intra-rater reliability of the smartphone inclinometer app (SPI) and flexicurve (FC) for assessing the kyphotic angle in individuals with thoracic kyphosis (TK).

METHODS

This study was conducted with 60 subjects (35 males, 25 females) aged 18 to 25 who presented to Kalyon Medical Center, Gaziantep, Turkey, between December 2021 and March 2022. The subjects were evaluated by two independent assessors using FC and SPI to measure the TK angle. The intraclass correlation coefficient (ICC) was analysed at a 95% confidence interval. The level of agreement between the methods was checked using Bland-Altman analysis.

RESULTS

Inter- and intra-rater measurements were strongly correlated (ICC 0.945 and 0.964, respectively). On the Bland-Altman plots, the FC showed poor agreement with the SPI app (mean difference, 19.81° ± 2.8°). The mean kyphotic angles were 45.15 ± 6.07° and 25.34 ± 4.96°, respectively, as measured by the SPI and FC.

CONCLUSION

This study demonstrated good intra- and inter-rater reliability of the SPI app and FC for the measurement of the spinal curvature (TK) angle in the sagittal plane. A weak agreement was discerned between the SPI and FC methods.

Validity and test-retest reliability of photogrammetry in adolescents with hyperkyphosis

BACKGROUND

A variety of noninvasive instruments have been introduced in the literature to assess thoracic curvature, although the psychometric properties of many of these instruments have not been satisfactory. Photogrammetry is a safe, accessible, and reliable technique. However, its validity in adolescents with hyperkyphosis has not yet been investigated.

OBJECTIVES

To investigate the validity and test-retest reliability of photogrammetry in the measurement of thoracic kyphosis among adolescents with hyperkyphosis.

METHODS

Fifty adolescents with hyperkyphosis participated in this study. The kyphosis angle was measured using radiography and photogrammetry. A two-way random model of the intraclass correlation coefficient (ICC_2,3) was used to estimate relative reliability. Absolute reliability was assessed by calculating the standard error of the measurements (SEM) and the minimal detectable change (MDC). Pearson's correlation coefficient was calculated to evaluate the validity of the photogrammetry technique. Bland-Altman plots were plotted to determine the agreement between the angles measured by radiography and photogrammetry.

RESULTS

There was a strong correlation between the values obtained from the photogrammetry technique and those from the radiography method (r = 0.94). The 95% limits of agreement indicated that the photogrammetric measurements of thoracic kyphosis angle might range from 2.4 degrees greater to 10.2 degrees lower than the Cobb radiographic angle. Photogrammetric measurements of thoracic kyphosis showed excellent test-retest reliability (ICC = 0.97; SEM = 1.67; MDC = 4.62).

CONCLUSION

High reliability of photogrammetry technique and its strong correlation with radiographic Cobb angle support the application of this technique for the measurement of thoracic kyphosis in clinical practice.

Is Breast Size Related to Prevalent Thoracic Vertebral Fracture? A Cross-Sectional Study

Large breasts may increase the likelihood of thoracic vertebral fractures by increasing the mechanical loading of the spine. We examined breast size as a factor associated with prevalent thoracic vertebral fractures, also considering its relationship with thoracic kyphosis and upper back extensor muscle endurance. Using a cross-sectional study, the design measurements collected were thoracic vertebral fractures (≥20% loss in vertebral body height on lateral radiograph), breast size (bra size converted to an ordinal breast size score), BMD (g/cm² averaged femoral neck, DXA), upper back extensor muscle endurance (isometric chest raise test), body composition (DXA), thoracic kyphosis (radiograph), and upper back pain (numerical rating scale). Correlations and multivariable logistic regression examined relationships between characteristics and their association with vertebral fracture. Participants were 117 healthy postmenopausal women. The 17 (15%) women with ≥1 thoracic vertebral fracture had larger breast size (mean difference [MD]: 2.2 sizes; 95% CI, 0.6 to 3.8 sizes), less upper back extensor muscle endurance (MD: -38.6 s; 95% CI, -62.9 to -14.3 s), and greater thoracic kyphosis (MD: 7.3°; 95% CI, 1.7° to 12.8°) than those without vertebral fracture. There were no between group differences in age, height, weight, and BMD. Breast size (r = -0.233, p = 0.012) and thoracic kyphosis (r = -0.241, p = 0.009) correlated negatively with upper back extensor muscle endurance. Breast size was unrelated to thoracic kyphosis (r = 0.057, p = 0.542). A (final) multivariable model containing breast size (OR 1.85; 95% CI, 1.10 to 3.10) and thoracic kyphosis (OR 2.04; 95%CI, 1.12 to 3.70) explained 18% of the variance in vertebral fracture. Breast size had a significant, but weak relationship with vertebral fracture (R ² = 0.10), which was independent of BMD and unrelated to thoracic kyphosis. Further work is needed to confirm larger breast size as a risk factor for vertebral fracture. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.