Complex thoracic malformations: is there an association between adolescent idiopathic scoliosis and pectus excavatum?

Abstract

Study Design: This is a retrospective review of 220 patients with adolescent idiopathic scoliosis (AIS).Objectives: When combined thoracic malformations occur scoliosis and pectus excavatum (PE) may limit the space available in the mediastinum resulting in cardiopulmonary compromise. The purpose of this study was to evaluate the prevalence of radiographic PE in patients with AIS. Methods: This is a retrospective review of 220 patients with AIS. Patients with syndromic scoliosis, neuromuscular disease or incomplete radiographs were excluded. The PE severity index (Haller Index = HI) was determined. Multivariate logistic regression was applied to HI, Cobb angle, sex and age. To define the interclass correlation for the HI a convenience sample of 10 patients was selected and interpreted by 3 authors. Results: Of the 357 scoliosis patients reviewed, 118 patients had complete imaging. The average age was 14 ± 3 years, 87% female. 30/118 (25%) of the patients had radiographic evidence of PE. 15/30 (50%) of the AIS patients with radiographic evidence of PE required operative correction for scoliosis. The OR for Cobb angle 1.03 (95%CI 0.0996-1.06; p-value 0.087). Interclass correlation was 0.91.Conclusions: An increased Cobb angle is associated with concomitant PE. Furthermore, the rate of AIS patients requiring surgery for their scoliosis that have severe PE would seem to be higher than in the general population. This would indicate patients at risk for cardiopulmonary compromise. Further work to understand the 3D relationship between these thoracic deformities may provide insight into the etiology and clinical significance of PE and AIS.