Pulmonary function in adolescent idiopathic scoliosis relative to the surgical procedure: A 10-year follow-up analysis

STUDY DESIGN.: Retrospective review. OBJECTIVE.: To assess long-term pulmonary function after surgical correction of adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA.: Pulmonary function is known to decline with increasing age. Although there are published reports on 2-and 5-year pulmonary function test outcomesafter various surgical approaches for adolescent idiopathic scoliosis, 10-year pulmonary function tests of these patients is unknown. METHODS.: Forty-nine patients were divided into two groups who underwent surgery for adolescent idiopathic scoliosis at a single institution. There were 46 female patients and three male patients. All group one patients (n = 38) had some form of chest wall disruption during their spinal fusion: group 1A (n = 17) underwent open anterior spinal fusion/instrumentation, group 1B (n = 9) had a combined open anteroposterior spinal fusion, and group 1C (n = 12) had a posterior spinal fusion/instrumentation with thoracoplasty. Group 2 patients (n = 11) underwent posterior spinal fusion/instrumentation with iliac crest bone graft and no chest cage disruption. We evaluated preoperative and 10-year pulmonary function test values. RESULTS.: Within-group comparison revealed that group 1 experienced no change in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1), but demonstrated a significant decrease in percent-predicted FVC (85% vs. 79%, P = 0.00086) and FEV1 values (80% vs. 76%, P = 0.038). Conversely, group 2 experienced a significant increase in both FVC (3.25L vs. 3.66L, P = 0.011) and FEV1 (2.77L vs. 3.10L, P = 0.0019), but no changes in percent-predicted values from baseline to 10 years. No changes were noted in percent-predicted values between 5 and 10 years in either group. CONCLUSION.: Intraoperative chest wall violation produced detrimental pulmonary effects, as reflected by reduced percent-predicted values at 10-year follow-up. Posterior-only procedures, which spared the chest wall, showed significant improvements in FVC and FEV1 absolute values without any change in percent-predicted values.