title: Does correction of preoperative coronal imbalance make a difference in outcomes of adult patients with deformity?
abstract: METHODS
  Retrospective study with prospectively collected outcomes data.
  
  
  OBJECTIVE
  Determine the significance of coronal balance on spinal deformity surgery outcomes.
  
  
  BACKGROUND
  Sagittal balance has been confirmed as an important radiographic parameter correlating with adult deformity treatment outcomes. The significance of coronal balance on functional outcomes is less clear.
  
  
  METHODS
  Eighty-five patients with more than 4 cm of coronal imbalance who underwent reconstructive spinal surgery were evaluated to determine the significance of coronal balance on functional outcomes as measured with the Oswestry Disability Index (ODI) and Scoliosis Research Society outcomes questionnaires. Sixty-two patients had combined coronal (>4 cm) and sagittal imbalance (>5 cm), while 23 patients had coronal imbalance alone.
  
  
  RESULTS
  Postoperatively, 85% of patients demonstrated improved coronal balance. The mean improvement in the coronal C7 plumb line was 26 mm for a mean correction of 42%. The mean preoperative sagittal C7 plumb line in patients with combined coronal and sagittal imbalance was 118 mm (range, 50-310 mm) and improved to a mean 49 mm. The mean preoperative and postoperative ODI scores were 42 (range, 0-90) and 27 (range, 0-78), for a mean improvement of 15 (36%) (P = 0.00001; 95% CI, 12-20). The mean Scoliosis Research Society scores improved by 17 points (29%) (P = 0.00). Younger age (P = 0.008) and improvement in sagittal balance (P = 0.014) were positive predictors for improved ODI scores. Improvement in sagittal balance (P = 0.010) was a positive predictor for improved Scoliosis Research Society scores. In patients with combined coronal and sagittal imbalance, improvement in sagittal balance was the most significant predictor for improved ODI scores (P = 0.009). In patients with preoperative coronal imbalance alone, improvement in coronal balance trended toward, but was not a significant predictor for improved ODI (P = 0.092).
  
  
  CONCLUSIONS
  Sagittal balance improvement is the strongest predictor of improved outcomes in patients with combined coronal and sagittal imbalance. In patients with coronal imbalance alone, improvement in coronal balance was not a factor for predicting improved functional outcomes.
authors.affiliation: University of California, Los Angeles, LA, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Daubs
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
authors.forename: Yongjung J
authors.initials: YJ
authors.lastname: Kim
authors.forename: Man
authors.initials: M
authors.lastname: Hung
authors.forename: Gene
authors.initials: G
authors.lastname: Cheh
authors.forename: Linda A
authors.initials: LA
authors.lastname: Koester
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D012600:Scoliosis / Q000503:physiopathology / Q000601:surgery*; D013131:Spine / Q000503:physiopathology / Q000601:surgery*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult