Thoracic mobility and its relation to pulmonary function and rib-cage deformity in patients with early onset idiopathic scoliosis: a long-term follow-up

Abstract

Abstract Study design A group of adult patients with idiopathic scoliosis, diagnosed before the age of ten, at a mean of 26.5 years after treatment with either brace or surgery during childhood and adolescence attended a clinical follow-up. Objectives To evaluate the relation between thoracic mobility, rib-cage deformity, and pulmonary function. Summary of background data Long-term studies of pulmonary function in relation to thoracic mobility after treatment in this patient group have not been published. Methods A total of 106 patients, 57 braced and 49 operated patients, attended the follow-up. We examined thoracic mobility (range of motion of the thoracic spine, thorax expansion, and breathing movements) and rib-cage deformity (curve size and trunk deformity) as well as pulmonary function, especially total lung capacity (TLC). Respiratory muscle strength was evaluated in a subgroup. Results Thoracic range of motion was significantly less among the surgically treated patients compared with both the brace-treated and comparison group. Thorax expansion and breathing movements during maximal breathing were significantly reduced in the scoliotic patients compared with the reference values, with no significant differences between the treatment groups. The brace-treated group had better pulmonary function than the operated group, as measured by the TLC, forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) (percentage of predicted values). The respiratory muscle strength was significantly lower only in the surgically treated patients when compared with reference values. The results of a multivariate analysis revealed that the strongest factors explaining TLC percentage of predicted were gender, brace model, and smoking habits. Conclusions Thoracic mobility was significantly reduced at mean 26.5 years after completed treatment in both brace-treated and surgically treated patients with early onset scoliosis, compared with the reference values, which did not influence TLC as strongly as gender, brace model, and smoking habits. Levels of evidence Level III.