title: The impact of posterior temporary internal distraction on stepwise corrective surgery for extremely severe and rigid scoliosis greater than 130°.
abstract: OBJECTIVE
  To investigate the efficacy and safety of temporary internal distraction corrective surgery for extremely severe scoliosis.
  
  
  METHODS
  Eleven scoliosis patients (3 males and 8 females) with curves ≥130° (mean 148.8°; range 130°-157°) who underwent a two-stage surgery, including a posterior temporary internal distraction correction and definitive posterior spinal correction with posterior pedicle screw instrumentation from 2008 to 2011 were retrospectively reviewed. Minimum follow-up was 2-years (mean 41.8 months; range 27.0-63.0 months). The analysis focused on the impact of temporary internal distraction on curve correction, pulmonary function tests (PFTs), complications and surgical outcomes. Neurosurveillance of sensory (somatosensory-evoked potentials) and motor (motor-evoked potentials) potential was performed in all cases. Posterior instrumentation was used in all patients.
  
  
  RESULTS
  After the use of internal distraction, the preoperative major curve (mean 148.8°; range 130°-157°) was corrected to a mean of 79° (range 63°-87°), the T5-T12 kyphosis Cobb angle (mean 79°; range 30°-97°) was corrected to a mean of 59° (range 20°-75°), the coronal imbalance (mean 0.8 cm; range -3.6 to 2.8 cm) was improved to a mean of 0.6 cm (range -1.5 to 2.0 cm), the forced vital capacity percentage (FVC%) was improved from 59.3 ± 11.6 to 68.7 ± 13.7, and the forced expiratory volume in 1 s (FEV1%) was improved from 61.4 ± 13.6 to 71.3 ± 9.3. The average increase in body height was 6.7 cm, and the dorsum razor was corrected to 3-5 cm. During definitive surgery, the final major curves were corrected to a mean of 55° (range 32°-72°), the T5-T12 kyphosis Cobb was corrected to 35° (range 15°-68°), the coronal imbalance was improved to 0.5 cm (range -1.2 to 1.8 cm), the FVC% was improved to 71.2 ± 8.3, the FEV1% was improved to 76.3 ± 16.7, the increase in body height was 3.1 cm, and the dorsum razor was corrected to 1-3 cm. The mean interval time between the two surgeries was 3.5 months. None of the patients exhibited postoperative neurologic deficits or infections. No instrument complications were found during the final follow-up.
  
  
  CONCLUSIONS
  Temporary internal distraction in a two-stage corrective surgery provided patients who had extremely severe and rigid scoliosis, an effective and safe solution for scoliosis without significant complications.
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Hu
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Hui
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Zhang
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Da-Geng
authors.initials: DG
authors.lastname: Huang
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Zhong-Kai
authors.initials: ZK
authors.lastname: Liu
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Yuan-Ting
authors.initials: YT
authors.lastname: Zhao
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Si-Min
authors.initials: SM
authors.lastname: He
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China.
authors.forename: Xue-Fang
authors.initials: XF
authors.lastname: Zhang
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China. hebr888@sohu.com.
authors.forename: Bao-Rong
authors.initials: BR
authors.lastname: He
authors.affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University College of Medicine, No. 76 Nanguo Road, Xi'an, 710054, Shaanxi, People's Republic of China. haodingjun@126.com.
authors.forename: Ding-Jun
authors.initials: DJ
authors.lastname: Hao
mesh_terms: D000293:Adolescent; D001827:Body Height; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D065289:Pedicle Screws; D011183:Postoperative Complications; D011184:Postoperative Period; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012600:Scoliosis / Q000503:physiopathology / Q000601:surgery*; D012720:Severity of Illness Index; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome; D014797:Vital Capacity; D055815:Young Adult
keywords: Internal distraction; Posterior fusion; Severe and rigid scoliosis; Surgical procedure