Prospective Pulmonary Function Comparison Following Posterior Spinal Fusion of Adolescent Idiopathic Scoliosis: Is There a Relationship Between Main Thoracic Curve Correction and PFT Improvement?
Purpose: To investigate if a correlation exists between the percentage of the main thoracic curve correction and postoperative PFT improvement following posterior spinal fusion (PSF) and instrumentation with iliac crest bone graft (ICBG).
Methods: 139 patients with AIS undergoing PSF and instrumentation with ICBG at a single institution were prospectively evaluated with pulmonary function tests (PFTs) assessing forced vital capacity (FVC) and forced expiratory volume in one second (FEV-1) preoperative and 2 years postoperative. All patients were divided into three groups depending upon the 2 year postoperative major curve correction percentage: Group 1 (n=29) Correction percentage between 70-100%; Group 2 (n=78) Correction percentage between 40-70%; Group 3 (n=32) Correction percentage between 0-40%.
Results: Average correction of the main thoracic curve at 2 year postoperation was 80% in Group 1, 52% in Group 2, and 29% in Group 3 (p<0 .0001). All 3 Groups increased both absolute and percent predictive value of PFTs at 2 year postoperative. However, there was no difference in the improvement seen comparing values from preoperative to postoperative among groups (FVC p="0.42," 0.29 L Group 1, 0.23 2, 0.39L 3) (FEV1 0.26 0.22 0.33L 3). Similarly, 4% 1% 2% group 3%
Conclusions: Although patients having a PSF with ICBG had improvement in PFTs, there was no correlation between the main thoracic curve correction and postoperative PFT improvement at 2 year postoperation.