title: Results of revision surgery after pedicle subtraction osteotomy for fixed sagittal imbalance with pseudarthrosis at the prior osteotomy site or elsewhere: minimum 5 years post-revision.
abstract: METHODS
  Retrospective review of pedicle subtraction osteotomy (PSO) cases.
  
  
  OBJECTIVE
  To report our results, radiographic and clinical outcomes at a minimum 5 years following revision surgery for pseudarthrosis after a PSO.
  
  
  BACKGROUND
  To our knowledge, there is no report on the results of revision surgery for pseudarthrosis after a PSO.
  
  
  METHODS
  Eighteen consecutive patients with pseudarthrosis after PSO (16 females/2 males; average age at surgery, 49.8 yr) treated with revision surgery at one institution were analyzed (average follow-up, 6.5 yr; range, 5-12 yr). Radiographic and clinical outcomes analysis was performed.
  
  
  RESULTS
  Sagittal vertical axis (SVA) and lumbar lordosis (LL) improved significantly after revision surgery (SVA, P = 0.000; LL, P = 0.024) and were maintained until ultimate post-revision follow-up (SVA, P = 0.170; LL, P = 0.729). Proximal junctional angle (P = 0.828), thoracic kyphosis (P = 0.828), and PSO angle (P = 0.717) achieved by the primary surgery were also maintained until ultimate post-revision. We increased the number of rods and/or changed them to 6.35-mm diameter in all patients. There were significant improvements post-revision in Oswestry Disability Index (45 vs. 37.9, P = 0.041) and Scoliosis Research Society pain subscale (2.6 vs. 3.1, P = 0.047) but not in Scoliosis Research Society total score or other subscales. Pelvic incidence greater than 60° demonstrated a trend toward poorer Oswestry Disability Index and Scoliosis Research Society scores (P > 0.05), but there were no significant differences between SVA greater or less than 11 cm.
  
  
  CONCLUSIONS
  Revision surgery for pseudarthrosis after PSO can provide acceptable radiographic and clinical outcomes at a minimum 5 years post-revision. Successful surgical outcomes may be achieved by using an increased number or size of implants and ample bone graft for complete fusion after revision surgery.
  
  
  METHODS
  4.
authors: *Department of Orthopaedic Surgery, Washington University School of Medicine in St. Louis, St. Louis, MO †Department of Orthopaedic Surgery, Spine Center, Hallym University Sacred Heart Hospital, Hallym University School of Medicine, Anyang, Gyeonggi-do, Republic of Korea; and ‡Department of Neurosurgery, Spine Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea.
authors: Yong-Chan
authors: YC
authors: Kim
authors: Lawrence G
authors: LG
authors: Lenke
authors: Seung-Jae
authors: SJ
authors: Hyun
authors: Jae-Hoo
authors: JH
authors: Lee
authors: Linda A
authors: LA
authors: Koester
authors: Kathy M
authors: KM
authors: Blanke
mesh_terms: D000328:Adult; D000368:Aged; D016025:Bone Transplantation / Q000009:adverse effects; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D007796:Laminectomy / Q000009:adverse effects; D008141:Lordosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D011542:Pseudarthrosis / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D020127:Recovery of Function; D012086:Reoperation; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects; D013131:Spine / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult