title: Pedicle screw versus hybrid construct instrumentation in adolescent idiopathic scoliosis: meta-analysis of thoracic kyphosis.
abstract: METHODS
  A quantitative meta-analysis was conducted on publishing studies reporting results of spinal surgery in adolescent idiopathic scoliosis with instrumentation of pedicle screw or hybrid construct.
  
  
  OBJECTIVE
  The primary objective is to get overview of the power to restore thoracic kyphosis using 2 different instrumentations.
  
  
  BACKGROUND
  During the past years, surgery has mainly focused on correcting the coronal curve, but nowadays, the aims of posterior fusion and instrumentation are to achieve a stable, well-balanced spine in the coronal as well as in the sagittal planes.
  
  
  METHODS
  A PubMed and EMBASE search was conducted using combinations of the key words "hybrid construct" or "pedicle screw" with "adolescent idiopathic scoliosis" up to October 2013. A hand search of reference lists of obtained articles was also performed.
  
  
  RESULTS
  A total of 24 studies were identified and included in this meta-analysis. Of this, 12 included pedicle screw group only, 5 included hybrid construct group only, and 7 included both groups. The total number of patients was 1615. Age ranged from 9 to 26 years, with a mean of 15. For pedicle screw group, we got standard mean difference (SMD) as 0.40 (95% confidence interval, 0.31-0.50); I= 91.4%. For hybrid construct group, we got SMD as 0.15 (95% confidence interval, 0.04-0.26). Both intervals of SMD lay in positive value side. Overall SMD was 0.30 (95% confidence interval, 0.23-0.37). The positive value of SMD means thoracic kyphosis improves after surgery, whereas negative value means kyphosis loss after surgery.
  
  
  CONCLUSIONS
  There is overall tendency for both instrumentations to restore thoracic kyphosis. Hybrid construct seems to be more powerful in restoring kyphosis than pedicle screw. Preoperative important factor was found to be reasonably distributed or balanced. For operative factor, rod stiffness, fashion of hybrid construct, in situ bending, and rod rotation maneuver could have influence on results of kyphosis in different ways. Loss of correction and limited restoration of loss may do exist after correction.
  
  
  METHODS
  3.
authors.affiliation: From the Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Cao
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Feng
authors.initials: F
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001858:Bone Nails; D002648:Child; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000601:surgery*; D008297:Male; D065289:Pedicle Screws; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D013904:Thoracic Vertebrae / Q000601:surgery*; D055815:Young Adult