%0 Journal Article %T The effect of growth on the correlation between the spinal and rib cage deformity: implications on idiopathic scoliosis pathogenesis %A Theodoros B Grivas %A Elias S Vasiliadis %A Constantinos Mihas %A Olga Savvidou %J Scoliosis %D 2007 %I BioMed Central %R 10.1186/1748-7161-2-11 %X Eighty three girls referred on the basis of their hump reading on the scoliometer, with a mean age of 13.4 years old (range 7¨C18), were included in the study. The spinal deformity was assessed by measuring the thoracic Cobb angle from the postero-anterior spinal radiographs. The rib cage deformity was quantified by measuring the rib-index at the apex of the thoracic curve from the lateral spinal radiographs. The rib-index is defined as the ratio between the distance of the posterior margin of the vertebral body and the most extended point of the most projecting rib contour, divided by the distance between the posterior margin of the same vertebral body and the most protruding point of the least projecting rib contour. Statistical analysis included linear regression models with and without the effect of the variable age. We divided our sample in two subgroups, namely the younger (7¨C13 years old) and the older (14¨C18 years old) than the mean age participants. A univariate linear regression analysis was performed for each age group in order to assess the effect of age on Cobb angle and rib index correlation.Twenty five per cent of patients with an ATI more than or equal 7 degrees had a spinal curve under 10 degrees or had a straight spine. Linear regressions between the dependent variable "Thoracic Cobb angle" with the independent variable "rib-index" without the effect of the variable "age" is not statistical significant. After sample split, the linear relationship is statistically significant in the age group 14¨C18 years old (p < 0.03).Growth has a significant effect in the correlation between the thoracic and the spinal deformity in girls with idiopathic scoliosis. Therefore it should be taken into consideration when trying to assess the spinal deformity from surface measurements. The findings of the present study implicate the role of the thorax, as it shows that the rib cage deformity precedes the spinal deformity in the pathogenesis of idiopathic scoliosis.Numero %U http://www.scoliosisjournal.com/content/2/1/11