Analysis of pulmonary function and chest cage dimension changes after thoracoplasty in idiopathic scoliosis

Study Design. A prospective study of 19 adolescents and seven adults with idiopathic scoliosis undergoing posterior spinal fusion with segmental spinal instrumentation and a concomitant thoracoplasty had pulmonary function evaluation before surgery and at selected time points up to a minimum 2 years after surgery.Objectives. The objectives were to determine the effects thoracoplasty had on pulmonary function and chest cage dimension changes at a minimum 2-year follow-up in idiopathic scoliosis patients.Summary of Background Data. The cosmetic benefits of thoracoplasty on the rib hump deformity are well accepted. The rib resection procedure allowed for procurement of autogenous bone used for the arthrodesis. Short and long-term pulmonary function evaluation was necessary to determine proper patient selection and any potential sequelae from the rib resection pro-cedure.Methods. All patients had pulmonary function tests consisting of forced vital capacity, forced expiratory volume in 1 second, and total lung capacity performed before surgery and 3 months, 1 year, and 2 years after surgery. Ten adolescents also had computed tomographic scans before and after surgery to evaluate chest cage dimension changes after the procedure.Results. The 3-month postoperative pulmonary function test values of the 19 adolescents experienced a statistically significant decline, averaging 16% (P<0.05), however, the mean values for each parameter returned to just slightly below the preoperative value at 2-years follow-up. The pulmonary function test values of the seven adults experienced a 27% initial decline 3 months after surgery and a residual 23% decline 2 years after surgery; both values were statistically significant (P< 0.05).Conclusions. We reserve the thoracoplasty procedure for adolescents and adults with preoperative pulmonary function values that will tolerate the morbidity associated with the rib resection. Adolescent patients appear to normalize their pulmonary function tests by 2 years follow-up, whereas long-term pulmonary function in the adult patient remains a concern.