title: Results of lumbar pedicle subtraction osteotomies for fixed sagittal imbalance: a minimum 5-year follow-up study.
abstract: METHODS
  Retrospective study.
  
  
  OBJECTIVE
  To report results at a minimum 5 years after pedicle subtraction osteotomy for fixed sagittal imbalance.
  
  
  BACKGROUND
  No one has reported results of pedicle subtraction osteotomies with a 5- to 8-year follow-up.
  
  
  METHODS
  Thirty-five consecutive patients with sagittal imbalance (29 females/6 males, average age at surgery, 53.1 years) treated with lumbar pedicle subtraction osteotomies (1 at L1, 13 at L2, 20 at L3, and 1 at L4) at 1 institution were analyzed (average follow-up, 5.8 years; range, 5-7.6 years). Radiographic and clinical outcomes analysis was performed.
  
  
  RESULTS
  There were no significant regional radiographic changes between 2 years postoperative and the ultimate follow-up (proximal junctional change, P = 0.30; thoracic kyphosis, P = 0.38; and lumbar lordosis, P = 0.84), although many patients did demonstrate an increasingly anterior C7 sagittal plumb with time. Ten pseudarthroses (29%) occurred in 8 patients and were revised between 2 and 5 years postoperative. There were no pseudarthroses at the osteotomy level (9 at the thoracolumbar junction, 1 at the LS junction), but at the levels added to the previous fusions. There was no degradation in Oswestry and Scoliosis Research Society (SRS) outcome scores between 2 years postoperative and ultimate follow-up (P = 0.23 and 0.90, respectively). Patients reported very good satisfaction (87%), good self-image (76%), good function (69%), and fair pain subscales (66%) at ultimate follow-up. Sagittal vertical axis <8 cm at ultimate follow-up was significant for better SRS outcomes scores (P = 0.038). Eight patients with revised pseudarthroses did not demonstrate poorer SRS outcomes scores (P = 0.52). Those 8 patients were queried after their pseudarthrosis revision surgery.
  
  
  CONCLUSIONS
  Pedicle subtraction osteotomy can provide satisfactory clinical and radiographic outcomes for patients with a minimum 5-year follow-up despite needing pseudarthrosis revision and some component of increasingly positive sagittal vertical axis between 2 years and 5 to 8 years of follow-up. The level of patient satisfaction and self-image subscales were high after more than 5 years of follow-up. Restoration and maintenance of sagittal vertical axis <8 cm were important to the ultimate sagittal reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Yongjung J
authors.initials: YJ
authors.lastname: Kim
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.forename: Gene
authors.initials: G
authors.lastname: Cheh
authors.forename: Christine
authors.initials: C
authors.lastname: Baldus
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007738:Kyphosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008141:Lordosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D017116:Low Back Pain / Q000209:etiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods*; D010147:Pain Measurement; D017060:Patient Satisfaction; D004856:Postural Balance; D011542:Pseudarthrosis / Q000209:etiology; D011859:Radiography; D020127:Recovery of Function; D012189:Retrospective Studies; D012600:Scoliosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome