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  • Oral presentation
  • Open Access

The influence of body mass index (BMI) on the reproducibility of surface topography measurements

  • 1,
  • 2,
  • 1,
  • 3 and
  • 2
Scoliosis20127 (Suppl 1) :O18

  • Published:


  • Body Mass Index
  • Surface Topography
  • High Body Mass Index
  • Spinal Deformity
  • Bony Landmark


Surface Topography can be used to evaluate patients with spinal deformity, especially adolescents with scoliosis in whom a reduced number of radiographic evaluations is desired. The Formetric 4D (Diers International GmbH, Schlangenbad, Germany) is a surface topography system that is able to identify anatomical landmarks and construct a 3-dimentional model of the spine using only surface features. One would guess that a slender patient with easily identifiable bony landmarks would be an ideal patient for this system, and that a patient with a higher Body Mass Index (BMI) would be more difficult to measure [15].

Materials and methods

In this study, fourteen female patients were measured 30 times each to evaluate the reproducibility of the Formetric measurements. The patients ranged in BMI from 16.9 to 29.0, and the reproducibility of each of the Formetric parameters was correlated to BMI.


Results showed that there was not a strong correlation between any of the individual surface topography parameters and the BMI. The reproducibility of the calculated scoliosis curve did correlate with BMI, however, (r = 0.65) and this correlation was significant (p = 0.012), showing that the higher the patient's BMI, the more variability was present in scoliosis angle calculations.


Overall, the reproducibility of the Formetric 4D was very good even in patients with higher BMI. The patient with the highest BMI (29) still had Formetric measurements that were +/- only 4.6 degrees for scoliosis curve calculations.

Authors’ Affiliations

Rosalind Franklin University North Chicago, USA
Illinois Bone and Joint Institute, USA
Northwestern University, USA


  1. Kane WJ: Scoliosis prevalence: a call for a statement of terms. Clin Orthop. 1977, Bethesda, MD: NCRP, 126: 43-6. 1987Google Scholar
  2. Tan C: Cobb Angle and Scoliosis. Musculoskeletal Consumer Review. 2009Google Scholar
  3. Chamberlain CC: Radiation doses to patients undergoing Scoliosis radiography. The British Journal of Radiology. 2002, 73: 847-853.View ArticleGoogle Scholar
  4. Ovadia D: Radiation-free quantitative assessment of Scoliosis: a Multi-Center prospective study. European Spine Journal. 2006, 16 (1): 97-105.PubMed CentralView ArticlePubMedGoogle Scholar
  5. Cole TJ: Weight-stature indices to measure underweight, overweight and obesity. Anthropometric assessment of nutritional status. Edited by: Himes JH. 1991, New York: Wiley-Liss, 83-111.Google Scholar


© Knott et al; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.