Different patterns of the pulmonary dysfunction between congenital scoliosis and idiopathic scoliosis

Objective: To investigate the difference in pulmonary function parameters between idiopathic scoliosis(IS) and congenital scoliosis(CS).Method: Preoperative pulmonary function tests(PFTs) were evaluated in 214 patients with spinal deformity(IS group,141 cases,CS group,73 cases).The correlation between pulmonary function parameters and Cobb angle of scoliosis was analyzed.According to the location of apical vertebra,214 patients were classified into thoracic group and non-thoracic scoliosis group.In the thoracic group,patients were divided into three subgroups,Cobb angle60°(group A),60°≤Cobb angle90°(group B),Cobb angle≥90°(group C).The parameters of pulmonary function(VC、FVC、FEV1、MMEF、MVV%) between IS and CS in both thoracic and non-thoracic groups were analyzed to see if there was any discrepancy between the two groups.The parameters of pulmonary function of the patients aged ≤10 years in the IS and CS groups were also compared simultaneously.Result: The percentage of predicted pulmonary volumes had negative correlation with the Cobb angle of the scoliosis(r=-0.40～-0.55).The percentage of predicted pulmonary volumes(VC、FVC、 MVV) of CS was significantly reduced than those of Cobb′s angle matched IS both in thoracic and nonthoracic groups.And in the thoracic scoliosis of IS group,the decrease of FEV1% was not as many as that for the CS group(80.0% vs 64.2%).Furthermore,in the groups with the age ≤10 years,the pulmonary function of CS was also more deteriorated than that of IS.Conclusion: The pattern of pulmonary function is different betweenIS and CS.The IS is restrictive pattern,however,the CS is mixed ventilation dysfunction.Whether the curve is thoracic or nonthoracic scoliosis,the impairment of lung function is more severe in CS than that in IS.The difference of pulmonary function between IS and CS may be existed before puberty.