title: Major complications in revision adult deformity surgery: risk factors and clinical outcomes with 2- to 7-year follow-up.
abstract: METHODS
  Retrospective cohort comparative study.
  
  
  OBJECTIVE
  To determine the prevalence of major complications, identify risk factors, and assess long-term clinical benefit after revision adult spinal deformity surgery.
  
  
  BACKGROUND
  No study has analyzed risk factors for major complications in long revision fusion surgery and whether or not occurrence of a major complication affects ultimate clinical outcome.
  
  
  METHODS
  Analysis of consecutive adult patients who underwent multilevel revision surgery for spinal deformity with a minimum 2-year follow-up was performed. All complications were classified as either major or minor. Outcome analysis was conducted with the Scoliosis Research Society and Oswestry Disability Index scores.
  
  
  RESULTS
  A total of 166 patients (mean age = 53.8 years) were identified with a mean follow-up of 3.5 years (range: 2-7). Primary diagnoses included idiopathic/de novo scoliosis (107), degenerative (35), trauma (7), neuromuscular scoliosis (6), congenital deformity (5), ankylosing spondylitis (2), tumor (2), Scheuermann kyphosis (1), and rheumatoid arthritis (1). Most common secondary diagnoses that necessitated revision surgery were adjacent segment disease, fixed sagittal imbalance, and pseudarthrosis. Overall, 34.3% of patients developed major complications (19.3% perioperative; 18.7% follow-up). Associated risk factors for perioperative complications were patient- (age > 60 years, medical comorbidities, obesity) and surgery-related (pedicle subtraction osteotomy). Performance of a 3-column osteotomy and postoperative radiographic changes that suggested progressive loss of sagittal correction were recognized as risk factors for follow-up complications. Equivalent outcome scores were reported by patients preoperatively, but those experiencing follow-up complications reported lower scores at the final follow-up.
  
  
  CONCLUSIONS
  Overall, 34.4% of patients experienced major complications after long revision fusion surgery. Different risk factors were identified for perioperative versus follow-up complications. The occurrence of a follow-up, not but perioperative, major complication seemed to have a negative impact on ultimate clinical outcome.
authors.affiliation: Department of Orthopaedics, Mount Sinai School of Medicine, New York, NY, USA.
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Cho
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.forename: Jin-Seok
authors.initials: JS
authors.lastname: Yi
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Pahys
authors.forename: Lukas P
authors.initials: LP
authors.lastname: Zebala
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Kang
authors.forename: Woojin
authors.initials: W
authors.lastname: Cho
authors.forename: Christine R
authors.initials: CR
authors.lastname: Baldus
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects*; D017060:Patient Satisfaction; D011859:Radiography; D012086:Reoperation / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D013122:Spinal Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects*; D013131:Spine / Q000601:surgery*; D016896:Treatment Outcome