ANALYSIS OF PULMONARY-FUNCTION AND CHEST CAGE DIMENSION CHANGES AFTERTHORACOPLASTY IN IDIOPATHIC SCOLIOSIS

Study Design. A prospective study of 19 adolescents and seven adults w ith idiopathic scoliosis undergoing posterior spinal fusion with segme ntal spinal instrumentation and a concomitant thoracoplasty had pulmon ary 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 che st cage dimension changes ata minimum 2-year follow-up in idiopathic s coliosis patients. Summary of Background Data. The cosmetic benefits o f thoracoplasty on the rib hump deformity are well accepted. The rib r esection procedure allowed for procurement of autogenous bone used for the arthrodesis. Short- and long-term pulmonary function evaluation w as necessary to determine proper patient selection and any potential s equelae from the rib resection procedure. Methods. All patients had pu lmonary function tests consisting of forced vital capacity, forced exp iratory volume in 1 second, and total lung capacity performed before s urgery and 3 months, 1 year, and 2 years after surgery. Ten adolescent s also had computed tomographic scans before and after surgery to eval uate chest cage dimension changes after the procedure. Results. The 3- month postoperative pulmonary function test values of the 19 adolescen ts experienced a statistically significant decline, averaging 16% (P < 0.05), however, the mean values for each parameter turned to just sli ghtly below the preoperative value at 2-years follow-up. The pulmonary function test values of the seven adults experienced a 27% initial de cline 3 months after surgery and a residual 23% decline 2 years after surgery; both values were statistically significant (P < 0.05). Conclu sions. We reserve the thoracoplasty procedure for adolescents and adul ts with preoperative pulmonary function values that will tolerate the morbidity associated with the rib resection. Adolescent patients appea r to normalize their pulmonary function tests by 2 years follow-up, wh ereas long-term pulmonary function in the adult patient remains a conc ern.