title: Role of the upper and lowest instrumented vertebrae in predicting the postoperative coronal balance in Lenke 5C patients after selective posterior fusion.
abstract: OBJECTIVE
  To investigate which pre- and postoperative radiographic parameters are significantly correlated with the immediate postoperative coronal balance (CB) in Lenke 5C AIS patients, and to identify any radiographic parameter that is correlated with the ultimate CB at a minimum follow-up of 2 years.
  
  
  METHODS
  Forty Lenke 5C AIS patients were recruited in the current study. Preoperative, immediate postoperative, and the latest follow-up radiographs were reviewed measuring various radiographic parameters related to UIV and LIV. The correlations between different parameters and CB were then studied.
  
  
  RESULTS
  The average follow-up time was 35.2 months. Correlation analysis showed that the following radiographic parameters significantly associated with the immediate postoperative CB in Lenke 5C patients: preoperative CB (r = 0.66, p < 0.01), preoperative UIV translation (r = 0.61, p < 0.01), preoperative LIV tilt (r = 0.61, p < 0.01), postoperative UIV translation (r = 0.51, p < 0.05), and postoperative LIV tilt (r = 0.50, p < 0.05). At the last follow-up, only the final UIV tilt was inversely correlated with the ultimate CB (r = -0.58, p < 0.05). Seven patients presented with coronal imbalance immediately after surgery. However, only one of the seven patients presented with coronal imbalance at the last follow-up, and the other six achieved C7PL-CSVL distance within 10 mm.
  
  
  CONCLUSIONS
  In Lenke 5C patients, preoperative UIV translation and LIV tilt are two important parameters that can predict the immediate postoperative CB. During the postoperative follow-up, UIV tilt may play a very important role in compensating for postoperative coronal imbalance.
authors.affiliation: Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Guo
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Bangping
authors.initials: B
authors.lastname: Qian
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.forename: Leilei
authors.initials: L
authors.lastname: Xu
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D004856:Postural Balance; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D013123:Spinal Fusion; D013131:Spine / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome