title: How to improve shoulder balance in the surgical correction of double thoracic adolescent idiopathic scoliosis.
abstract: METHODS
  A retrospective comparative study.
  
  
  OBJECTIVE
  To evaluate the shoulder balance resulting from the correction of double thoracic adolescent idiopathic scoliosis (AIS) comparing rod derotation (RD) with direct vertebral rotation (DVR) and RD only after pedicle screw instrumentations.
  
  
  BACKGROUND
  This is the first report on the effect of DVR on the shoulder balance using segmental pedicle screw instrumentation in the treatment of double thoracic AIS with minimum 5-year follow-up.
  
  
  METHODS
  Patients with double thoracic AIS (n = 57) were treated by fusing both thoracic curves with RD and DVR (n=35), or RD (n=22) methods and retrospectively studied with a minimum 5 years of follow-up.
  
  
  RESULTS
  In the RD with DVR group, the preoperative proximal thoracic curve of 40.2° improved to 17.9° postoperatively and 19.9° at the last follow-up. In the RD group, the preoperative proximal thoracic curve of 37.5° improved to 22.4° postoperatively and 23.2° at the last follow-up. In the RD with DVR group, the preoperative distal thoracic curve of 56.6° improved to 16.1° postoperatively and 16.7° at the last follow-up. In the RD group, the preoperative distal thoracic curve of 50.6° improved to 17.8° postoperatively and 18.2° at the last follow-up. In the RD with DVR group, the average preoperative shoulder height difference of 16.3 mm had improved to 7.2 mm postoperatively and was 7.0 mm at the last follow-up. In the RD group, the average preoperative shoulder height difference of 15.1 mm had changed to 7.5 mm postoperatively and was 7.3 mm at the last follow-up.
  
  
  CONCLUSIONS
  Shoulder balance had not significantly improved even with additional correction method of DVR using segmental pedicle screw instrumentation in double thoracic AIS. The proximal thoracic curve was rigid and corrected less in both groups. Therefore, less correction of the distal thoracic curve effectively achieves better shoulder balance.
  
  
  METHODS
  3.
authors.affiliation: *Seoul Spine Institute, Inje University Sanggye Paik Hospital, College of Medicine, Seoul, Korea; and †Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea.
authors.forename: Dong-Gune
authors.initials: DG
authors.lastname: Chang
authors.forename: Jin-Hyok
authors.initials: JH
authors.lastname: Kim
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Dong-Ju
authors.initials: DJ
authors.lastname: Lim
authors.forename: Kee-Yong
authors.initials: KY
authors.lastname: Ha
authors.forename: Se-Il
authors.initials: SI
authors.lastname: Suk
mesh_terms: D000293:Adolescent; D001863:Bone Screws / Q000706:statistics & numerical data; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods*; D004856:Postural Balance; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000601:surgery; D012782:Shoulder / Q000000981:diagnostic imaging* / Q000601:surgery; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D016896:Treatment Outcome