title: Complications and outcomes of pedicle subtraction osteotomies for fixed sagittal imbalance.
abstract: METHODS
  Radiographic analysis, outcomes analysis (pain scale, Oswestry, SRS-24), and accumulation of complications. Outcomes and complications collected prospectively. Radiographic analysis performed retrospectively.
  
  
  OBJECTIVE
  To assess the benefits and stress complications of pedicle subtraction osteotomies for patients with fixed sagittal imbalance.
  
  
  BACKGROUND
  Few reports on pedicle subtraction osteotomies exist in the peer-review literature for conditions other than trauma and ankylosing spondylitis.
  
  
  METHODS
  Thirty-three consecutive patients with sagittal imbalance treated with lumbar pedicle subtraction osteotomy at one institution (minimum 2-year follow-up) were analyzed. Complications were also analyzed for the entire group of consecutive pedicle subtraction osteotomies done at our institution to date (n = 66).
  
  
  RESULTS
  For the 33 patients with minimum 2-year follow-up, there were significant improvements in the overall Oswestry score (P 0.0001) and pain score (P = 0.0001). Most patients reported improvement in pain and self-image and reported overall satisfaction based on ultimate SRS-24 questionnaire. There was one pseudarthrosis in the lumbar spine through an area of pedicle subtraction osteotomy (area of previous laminectomy and nonunion), and six patients had thoracic pseudarthroses (levels other than the osteotomy level) and one patient had a pseudarthrosis at L5-S1. Two patients had acute angular kyphosis at the thoracolumbar junction at the proximal end of the construct. Five patients who experienced transient neurologic deficits resolved their deficits after central canal enlargement.
  
  
  CONCLUSIONS
  The clinical result with pedicle subtraction osteotomy is reduced with pseudarthrosis in the thoracic or lumbar spine and subsequent breakdown adjacent to the fusion. For patients with a degenerative sagittal imbalance etiology the results were worse and the complications were higher. Central canal enlargement is critical.
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical; D001803:Blood Transfusion / Q000706:statistics & numerical data; D005260:Female; D050815:Fractures, Compression / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D016268:Internal Fixators; D007403:Intervertebral Disc / Q000601:surgery; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D007738:Kyphosis / Q000150:complications / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D010027:Osteotomy / Q000706:statistics & numerical data*; D017060:Patient Satisfaction; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D011446:Prospective Studies; D011542:Pseudarthrosis / Q000453:epidemiology / Q000209:etiology; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000150:complications / Q000601:surgery; D012649:Self Concept; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D016103:Spinal Fractures / Q000453:epidemiology / Q000209:etiology; D013123:Spinal Fusion / Q000295:instrumentation; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000601:surgery; D011795:Surveys and Questionnaires; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging; D016896:Treatment Outcome