Correlation between respiratory function and spine and thorax deformity in children with mild scoliosis

Idiopathic scoliosis (IS) is the most common 3-dimensional deformation abnormality of the spine with direct effects on the thoracic cage and can potentially affect respiratory function. The purpose of the present study was to recognize whether the 3-dimensional displacement of the spine and trunk as a consequence of IS directly influences and diminishes respiratory function in children with mild IS. The study involved 68 children aged 10 to 12 years with mild thoracic or thoracolumbar IS who were the outpatients of the local Center for Corrective Gymnastics. The study consisted of 2 interrelated parts: the body posture examination using a Moiré topography and the spirometric examination including measurements of basic ventilatory parameters (vital capacity [VC], forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], and FEV1/FVC). For the majority of subjects, the results of VC were within the normal range and did not confirm the existence of features characteristic for ventilatory functional restriction. The VC does not depend on the curvature angle value or the degree of rotation of vertebral bodies. It was observed that VC in children with mild IS of 20 to 30 degree depended on thoracic kyphosis, that is, length, depth, and the thoracic kyphosis length/depth indicator. The results of performed study showed that in children with mild IS the lung volumes are reduced not only by an increased angle of the lateral curvature but also by the degree of loss of normal thoracic kyphosis. The regular respiratory function testing and back-shape analysis are advisable in children with thoracic and thoracolumbar mild IS.