title: Incidence of Pleural Fluid and Its Associated Risk Factors After Posterior Spinal Fusion in Patients With Adolescent Idiopathic Scoliosis.
abstract: METHODS
  Retrospective review of prospectively-collected data.
  
  
  OBJECTIVE
  To determine the incidence pleural fluid (PF) and its associated risk factors after posterior corrective spinal fusion (PCSF) in patients with adolescent idiopathic scoliosis (AIS).
  
  
  BACKGROUND
  Subclinical PF is often observed after PCSF in AIS patients. However, a few reports have been published regarding the incidence, characteristics, and associated risk factors.
  
  
  METHODS
  A total of 76 AIS patients who underwent PCSF and followed up for a minimum of 1 year were enrolled in this study. The volume of PF in each thorax was detected with thoracolumbar CT images taken preoperatively, at 1 week and 3 months follow up. Patient demographics, comorbidities, operation factors, serum albumin levels, scoliotic parameters, occurrence of malposition of pedicle screw insertion, and complications were collected and analyzed with univariate and multivariate analyses.
  
  
  RESULTS
  There were 71 female and five male patients (mean age, 16.2 yrs). All cases had a right convex curve in thoracic spine. Other causes of PF were not observed. PF was detected in 54 cases (71%) at 1 week postsurgery. It accumulated bilaterally in 36 cases, only in the right thorax in 13 cases, and only in the left thorax in five cases. There was significant difference between the depth of PF in the right and left sides (P < 0.001). The independent risk factor for PF was increased number of fused levels (OR: 3.88, 95% CI: 1.31-11.47). The mean coronal curve correction rate and other scoliotic factors were not significantly correlated.
  
  
  CONCLUSIONS
  PF was observed in 71% of the patients who underwent PCSF for AIS. The right thorax was more commonly involved than the left. A higher number of fused levels (11 or more) was an independent risk factor of PF.
  
  
  METHODS
  3.
authors.affiliation: Department of Orthopedic Surgery, Osaka City University Graduate school of Medicine, Osaka, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hayashi
authors.forename: Hidetomi
authors.initials: H
authors.lastname: Terai
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Toyoda
authors.forename: Akinobu
authors.initials: A
authors.lastname: Suzuki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hoshino
authors.forename: Koji
authors.initials: K
authors.lastname: Tamai
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ohyama
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D010996:Pleural Effusion / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012600:Scoliosis / Q000453:epidemiology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000706:statistics & numerical data