title: Prospective pulmonary function comparison following posterior segmental spinal instrumentation and fusion of adolescent idiopathic scoliosis: is there a relationship between major thoracic curve correction and pulmonary function test improvement?
abstract: METHODS
  Prospective clinical study.
  
  
  OBJECTIVE
  To investigate if a correlation exists between various parameters including major thoracic curve correction and postoperative pulmonary function test (PFT) improvement at 2 years postoperative following posterior segmental spinal fusion (PSSF) and instrumentation with iliac crest bone graft (ICBG).
  
  
  BACKGROUND
  There are no studies available on the correlation between major thoracic curve correction and postoperative PFT improvement following PSSF and instrumentation with ICBG with a homogenous diagnosis, similar operation method, and similar age population.
  
  
  METHODS
  One hundred thirty-nine patients with adolescent idiopathic scoliosis (Lenke type 1-4), undergoing PSSF and instrumentation with ICBG at a single institution, were before surgery and 2 years after surgery prospectively evaluated in regard to PFTs, assessing forced vital capacity, and forced expiratory volume in 1 second. PFTs change at 2 years postoperative was compared by the various parameters including major thoracic Cobb curve correction and the types of instrumentation. We defined a significant clinical improvement as a 10% or more increase of percent predictive FEV1 value at 2 years postoperative.
  
  
  RESULTS
  PSSF and instrumentation with ICBG demonstrated statistically significant improvement of absolute and percent-predicted PFTs at 2 years postoperative. There was a significant clinical improvement in 31 patients (22%) at 2 years postoperative. Significant clinical improvement was related to thoracic pedicle screw instrumentation (vs. thoracic hook instrumentation, P = 0.030). Absolute amount of major thoracic Cobb correction, magnitude of the residual curve, correction percentage of the major thoracic Cobb, the number of fused vertebrae, Risser sign, and age at surgery did not demonstrate any significant positive or negative correlation (-0.3 <Pearson correlation coefficient <0.3).
  
  
  CONCLUSIONS
  Patients having a PSSF and instrumentation with ICBG statistically significant improvement of absolute and percent-predicted PFTs at 2 years postoperative. There was a significant clinical improvement in 31 patients (22%) at 2 years postoperative. A significant clinical improvement was related with thoracic pedicle screw instrumentation.
authors.affiliation: Spinal Deformity Service, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Yongjung J
authors.initials: YJ
authors.lastname: Kim
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
authors.forename: Gene
authors.initials: G
authors.lastname: Cheh
authors.forename: Joetta
authors.initials: J
authors.lastname: Whorton
authors.forename: Brenda
authors.initials: B
authors.lastname: Sides
mesh_terms: D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D011182:Postoperative Care; D011183:Postoperative Complications / Q000175:diagnosis / Q000517:prevention & control*; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D013904:Thoracic Vertebrae / Q000601:surgery