title: The effect of growing Rod treatment on coronal balance during serial lengthening surgeries in early onset scoliosis.
abstract: BACKGROUND
  Gaining and maintaining spinal balance after surgery is of great importance for early onset scoliosis (EOS). However, tendency of balance on the coronal plane after growing rod surgery has not been studied before. This study evaluated the effect of growing rod treatment on coronal balance (CB) during serial lengthening surgeries in EOS.
  
  
  METHODS
  All EOS patients treated with growing rod technique in our hospital from August 2002 to June 2014 were retrospectively reviewed. Radiographic data before the sixth lengthening surgery were measured on the posteroanterior X-ray images, including global CB (C7 plumbline-central sacral vertical line, C7PL-CSVL), regional CB (apical vertebrae-CSVL), Cobb angle of the main curve and pelvic inlet width (PIW). Global CB index and regional CB index were calculated as dividing global CB and regional CB by PIW, respectively. The changes of these parameters during repeated lengthening surgeries were analyzed.
  
  
  RESULTS
  Five hundred seventy Radiographs of 67 patients, including 134 images before and after growing rod insertion surgeries and 436 images pre- and post-lengthening surgeries were measured. Global CB and global CB index did not show significant differences between every two set points during lengthening procedures (P > 0.05). The percentage of patients with C7PL-CSVL distance more than 20 mm roughly ranged from 30 to 45 % during the lengthening process. With regards to regional CB and main curve Cobb angles, there were significant differences between every two adjacent set points during the first five lengthening surgeries (P < 0.05).
  
  
  CONCLUSIONS
  Global CB did not significantly change during serial lengthening surgeries and C7PL-CSVL distances of greater than 20 mm comprised of over one third of patients during growing rod treatment. However, worsening regional CB and Cobb angles of the main curve during lengthening intervals were corrected by lengthening manipulation and maintained at a stable level.
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Wen-jing
authors.initials: WJ
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Zhi-jian
authors.initials: ZJ
authors.lastname: Sun
authors.affiliation: Department of Trauma & Orthopaedic Surgery, Lister Hospital, Stevenage, UK.
authors.forename: Shi-gong
authors.initials: SG
authors.lastname: Guo
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Gui-xing
authors.initials: GX
authors.lastname: Qiu
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Jian-xiong
authors.initials: JX
authors.lastname: Shen
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Yi-peng
authors.initials: YP
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China.
authors.forename: Shu-gang
authors.initials: SG
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dong Cheng District Shuai Fu Yuan No.1, Beijing, 100730, China. zhaoyupumch@126.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008297:Male; D011859:Radiography / Q000639:trends; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D016896:Treatment Outcome
keywords: Coronal balance; Early onset scoliosis; Growing rod; Lengthening surgery