Preoperative pulmonary function and respiratory muscle strength in Portuguese adolescents with idiopathic scoliosis.

Idiopathic scoliosis is a 3-dimensional deformity of the spine, with direct effects on the thoracic cage, characterized by the lateral displacement (greater than 10◦) and rotation of vertebral bodies during periods of rapid somatic growth.1 Adolescent idiopathic scoliosis (AIS) is found between the age of 10 and skeletal maturity2 and its prevalence is estimated at 2--4% in children between 10 and 16 years of age.2,3 This condition encompasses several complications including back pain, poor body image, and impaired pulmonary function.3 In fact, previous studies have shown a decreased pulmonary function in adolescents with idiopathic scoliosis,4 and an inverse correlation between scoliosis Cobb angles and pulmonary function.4 Adolescents with severe scoliosis, with Cobb angles above 45--50◦, are routinely managed with spinal fusion surgery.3 In addition to the mechanical restriction to ventilation, changes in spine and thoracic cage position may alter the length of respiratory muscles influencing the ability to generate tension. Therefore, the aim of this study was to evaluate pulmonary function and respiratory muscle strength in subjects with AIS. From November 2012 to May 2013, 12 females with AIS (15.1 ± 1.6 years of age) and 12 age-matched controls (15.2 ± 1.4 years of age) were enrolled in this study. The AIS group was recruited in the Paediatrics Department of Centro Hospitalar Porto-Hospital Santo António, Portugal, whereas the control group was recruited in the Porto metropolitan area. Eligible participants were those idiopathic scoliosis preoperative patients aged 10 or over, with thoracic Cobb angles of ≥40◦. Exclusion criteria for this study included bronchial asthma and other pulmonary, cardiovascular or skeletal muscle problems, and previous spinal surgery. The study procedures were in accordance with the ethical stan-