title: Risk Factors for Proximal Junctional Kyphosis Associated With Dual-rod Growing-rod Surgery for Early-onset Scoliosis.
abstract: A retrospective, multicenter study.
  
  
  
  To identify risk factors for proximal junctional kyphosis (PJK) when treating early-onset scoliosis (EOS) with dual-rod growing-rod (GR) procedure.
  
  
  
  The risk factors for PJK associated with GR treatment for EOS have not been adequately studied.
  
  
  
  We evaluated clinical and radiographic results from 88 patients with EOS who underwent dual-rod GR surgery in 12 spine centers in Japan. The mean age at the time of the initial surgery was 6.5±2.2 years (range, 1.5-9.8 y), and the mean follow-up period was 3.9±2.6 years (range, 2.0-12.0 y). Risk factors for PJK were analyzed by binomial multiple logistic regression analysis. The potential factors analyzed were sex, etiology, age, the number of rod-lengthening procedures, coronal and sagittal parameters on radiographs, the type of foundation (pedicle screws or hooks), the uppermost level of the proximal foundation, and the lowermost level of the distal foundation.
  
  
  
  PJK developed in 23 patients (26%); in 19 of these, the proximal foundation became dislodged following PJK. Binomial multiple logistic regression analysis identified the following significant independent risk factors for PJK: a lower instrumented vertebra at or cranial to L3 [odds ratio (OR), 3.32], a proximal thoracic scoliosis of ≥40 degrees (OR, 2.95), and a main thoracic kyphosis of ≥60 degrees (OR, 5.08).
  
  
  
  The significant independent risk factors for PJK during dual-rod GR treatment for EOS were a lower instrumented vertebra at or cranial to L3, a proximal thoracic scoliosis of ≥40 degrees, and a main thoracic kyphosis of ≥60 degrees.
authors.affiliation: *Department of Advanced Therapy for Spine and Spinal Cord Disorders, Keio University, Tokyo†Department of Orthopedic Surgery, National Hospital Organization, Kobe Medical Center, Hyogo‡Department of Orthopedic Surgery, Meijo Hospital, Nagoya§Department of Orthopedic Surgery, Fukuoka Children's Hospital, Fukuoka∥Department of Orthopedic Surgery, Hokkaido University Graduate School of Med., Hokkaido¶Department of Orthopedic Surgery, Niigata University Medical and Dental Hospital, Niigata#Department of Orthopedic Surgery, Iwate Medical University, Morioka**Department of Orthopedic Surgery, Seirei Sakura Citizen Hospital, Chiba††Department of Orthopedic Surgery, Dokkyo Medical University School of Medicine, Tochigi‡‡Department of Orthopedic Surgery, Nagoya University, Aichi§§Department of Orthopedic Surgery, University of Tokyo, Tokyo∥∥Department of Orthopedic Surgery, Kagoshima University, Kagoshima¶¶Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.forename: Koki
authors.initials: K
authors.lastname: Uno
authors.forename: Teppei
authors.initials: T
authors.lastname: Suzuki
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kawakami
authors.forename: Taichi
authors.initials: T
authors.lastname: Tsuji
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Yanagida
authors.forename: Manabu
authors.initials: M
authors.lastname: Ito
authors.forename: Toru
authors.initials: T
authors.lastname: Hirano
authors.forename: Ken
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Shohei
authors.initials: S
authors.lastname: Minami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taneichi
authors.forename: Shiro
authors.initials: S
authors.lastname: Imagama
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takeshita
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007738:Kyphosis / Q000209:etiology*; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D065289:Pedicle Screws; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects*; D013904:Thoracic Vertebrae / Q000601:surgery*; D016896:Treatment Outcome