title: Posterior spinal fusion for scoliosis in duchenne muscular dystrophy diminishes the rate of respiratory decline.
abstract: METHODS
  To assess the rate of decline in pulmonary function in Duchenne muscular dystrophy (DMD) before and after posterior spinal fusion for scoliosis.
  
  
  OBJECTIVE
  To compare the rate of respiratory decline using percent normal forced vital capacity (%FVC) measurements before and after posterior spinal fusion.
  
  
  BACKGROUND
  Posterior spinal fusion for scoliosis is used widely in DMD, although the long-term pulmonary effects have not been well established.
  
  
  METHODS
  Fifty-six patients were assessed. Percent forced vital capacity was the outcome parameter with data analysis using a mixed-model repeated-measures ANOVA and paired t tests. Group 1: Inclusion criteria were a diagnosis of DMD, 2 or more pulmonary function tests presurgery, and 2 or more postsurgery. Group 2: The rates of respiratory decline before and after spinal fusion for the whole study population were determined by within-subjects mixed-model regression analysis to account for the varying number of FVC studies between patients and unequal spacing between tests.
  
  
  RESULTS
  Group 1: 20 patients. Mean length of time of respiratory value determination was 2.5 +/- 1.0 years presurgery and 5.6 +/- 2.8 years postsurgery. Mean rate of decline presurgery was 8.0% +/- 4.1% per year, which decreased to 3.9% +/- 1.9% per year postsurgery (paired t test = 4.58, P < 0.0001). Group 2: 56 patients. The respiratory value determinations ranged from 4 years presurgery to 8 years postsurgery. The rates of respiratory decline based on the whole study population were 4% per year presurgery, which decreased to 1.75% per year postsurgery (F-test comparison of slopes = 19.71, P < 0.0001).
  
  
  CONCLUSIONS
  Posterior spinal fusion for scoliosis in DMD is associated with a significant decrease in the rate of respiratory decline postsurgery compared with presurgery rates.
authors.affiliation: Department of Medicine (Division of Respiratory Diseases), Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Velasco
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Colin
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: Basil T
authors.initials: BT
authors.lastname: Darras
authors.forename: Frederic
authors.initials: F
authors.lastname: Shapiro
mesh_terms: D000293:Adolescent; D002648:Child; D018450:Disease Progression; D006801:Humans; D020388:Muscular Dystrophy, Duchenne / Q000150:complications / Q000503:physiopathology*; D012044:Regression Analysis; D012137:Respiratory System / Q000503:physiopathology*; D012600:Scoliosis / Q000209:etiology / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome; D014797:Vital Capacity / Q000502:physiology