title: Pedicle screw fixation combined with intermediate screw at the fracture level for treatment of thoracolumbar fractures: A meta-analysis.
abstract: BACKGROUND
  Use of a pedicle screw at the level of fracture, also known as an intermediate screw, has been shown to improve clinical results in managing thoracolumbar(TL) fractures, but there is a paucity of powerful evidence to support the claim. The aim of this study was to compare outcomes between pedicle screw fixation combined with intermediate screw at the fracture level and conventional pedicle screw fixation (one level above and one level below the fracture level) for thoracolumbar (TL) fractures.
  
  
  METHODS
  A meta-analysis of cohort studies was conducted between pedicle screw fixation combined with intermediate screw at the fracture level (combined screw group) and conventional pedicle screw fixation (conventional group) for the treatment of TL fractures from their inception to December 2015. An extensive search of studies was performed in PubMed, Medline, Embase, and the Cochrane library. The following outcome measures were extracted: visual analogue scale (VAS), operation time and intraoperative blood loss, Cobb angle and anterior vertebral height (AVH), and complications. Data analysis was conducted with RevMan 5.3.5.
  
  
  RESULTS
  From 10 relevant studies identified, 283 patients undergoing pedicle screw fixation combined with intermediate screw at the fracture level were compared with 285 conventional pedicle screw procedures. The pooled analysis showed that there was statistically significant difference in terms of postoperative Cobb angle (95% confidence interval (CI), -3.00, -0.75; P = 0.001) and AVH (95% CI, 0.04, 12.23; P = 0.05), correction loss (Cobb angle: P < 0.0001; AVH: P < 0.0001) and implant failure rate (95% CI, 0.06, 0.62; P = 0.006), and blood loss (W 95% CI, 2.22, 23.60; P = 0.02) between 2 groups. But in terms of other complications, there were no differences between 2 groups (95% CI, 0.23, 2.04; P = 0.50). No difference was found in operation time (95% CI, -5.36, 14.67; P = 0.36) and VAS scores (95% CI, -0.44, 0.01; P = 0.06).
  
  
  CONCLUSIONS
  The combined screw fixation technique was associated with better reduction of the fractured vertebrae, less correction loss in the follow-up, and lower implant failure rate. Given the lack of robust clinical evidence, these findings warrant verification in large prospective registries and randomized trials with long-term follow-up.
authors.affiliation: Department of Orthopaedics Department of Ultrasonography, Liaocheng People's Hospital, Liaocheng City Department of Orthopaedics, Caoxian People's Hospital, Heze City, Shandong Province, China.
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Li
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Geng
authors.forename: Dawei
authors.initials: D
authors.lastname: Luo
authors.forename: Jinzhu
authors.initials: J
authors.lastname: Ma
mesh_terms: D001863:Bone Screws; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008159:Lumbar Vertebrae / Q000293:injuries* / Q000601:surgery; D065289:Pedicle Screws; D016103:Spinal Fractures / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000293:injuries* / Q000601:surgery; D016896:Treatment Outcome