title: Coronal imbalance in degenerative lumbar scoliosis: Prevalence and influence on surgical decision-making for spinal osteotomy.
abstract: OBJECTIVE
  There is a paucity of information on the pre-operative coronal imbalance in patients with degenerative lumbar scoliosis (DLS) and its influence on surgical outcomes.
  
  
  METHODS
  A total of 284 DLS patients were recruited into this study, among whom 69 patients were treated surgically and the remaining 215 patients conservatively Patients were classified based on the coronal balance distance (CBD): Type A, CBD < 3 cm; Type B, CBD > 3 cm and C7 Plumb Line (C7PL) shifted to the concave side of the curve; Type C, CBD > 3 cm and C7PL shifted to the convex side.
  
  
  RESULTS
  A total of 99 of the 284 (34.8%) patient presented with a pre-operative coronal imbalance (mean CBD: 48.5, standard deviation 18.7 mm). More patients with a Type B malalignment were observed than with a Type C malalignment (62 versus 37). A total of 21 pf the 69 (30.4%) surgically treated patients had a post-operative coronal imbalance, which was found to be more prevalent in Type C patients (p < 0.001). At follow-up, less improvement was observed in terms of Short Form-36 Physical Component Score and visual analogue score for back pain (p = 0.034 and 0.025, respectively) in Type C patients.
  
  
  CONCLUSIONS
  This study shows that patients with Type C coronal malalignment may be at greater risk of post-operative coronal imbalance following posterior osteotomy. Cite this article: Bone Joint J 2016;98-B:1227-33.
authors: Nanjing Drum Tower Hospital, 321 Zhongshan Road, Nanjing, 210008, China.
authors: H
authors: H
authors: Bao
authors: Nanjing Drum Tower Hospital, 321 Zhongshan Road, Nanjing, 210008, China.
authors: P
authors: P
authors: Yan
authors: Nanjing Drum Tower Hospital, 321 Zhongshan Road, Nanjing, 210008, China.
authors: Y
authors: Y
authors: Qiu
authors: Nanjing Drum Tower Hospital, 321 Zhongshan Road, Nanjing, 210008, China.
authors: Z
authors: Z
authors: Liu
authors: Chinese University of Hong Kong, 30-32 Ngan Shing Street, Shatin, Hong Kong, China.
authors: F
authors: F
authors: Zhu
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D015331:Cohort Studies; D000072700:Conservative Treatment / Q000379:methods; D003657:Decision Making; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators / Q000706:statistics & numerical data; D007593:Joint Instability / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D018579:Patient Selection; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D012600:Scoliosis / Q000175:diagnosis / Q000601:surgery* / Q000628:therapy; D016896:Treatment Outcome
keywords: Classification; Coronal imbalance; Degenerative lumbar scoliosis; Osteotomy