title: [Unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion: a meta-analysis of available evidence].
abstract: OBJECTIVE
  To evaluate the effectiveness of unilateral versus bilateral pedicle screw fixation in lumbar spinal fusion.
  
  
  METHODS
  Studies on comparison between unilateral and bilateral pedicle screw fixation in lumbar spinal fusion were identified from Medline, EMBASE, Cochrane CENTRAL (Third Quarter 2011), ScienceDirect, OVID, SpringerLink and The China Biological Medicine Database, and searched several related journals by hand. The included trials were screened out according to the criterion of inclusion and exclusion. The quality of included trials was evaluated. Data were extracted by two reviewers independently. RevMan 5.1.1 was used for data analysis.
  
  
  RESULTS
  Seven studies involving 480 patients were included, 246 in unilateral group, and 234 in bilateral group. The results of meta-analysis indicated that statistically significant difference were observed between the two fixation procedures in mean operation time (MD = -24.39, 95%CI: -33.16 to 15.61, P < 0.01), the amount of bleeding (MD = -118.73, 95%CI: -143.43 to -94.03, P < 0.01). There were no difference in inpatient stay, fusion rate, complication rate and excellent and good rate.
  
  
  CONCLUSIONS
  Both unilateral and bilateral pedicle screw fixation are effective in lumbar spinal fusion. To compare with bilateral fixation, unilateral fixation can shorten operation time, reduce amount of bleeding and medical expenses. And there is a similar effect of inpatient stay, fusion rate, complication rate and excellent and good rate.
authors.affiliation: Department of Orthopaedics, Tianjin Hospital, Tianjin, China.
authors.forename: Jia-cheng
authors.initials: JC
authors.lastname: Zang
authors.forename: Xin-long
authors.initials: XL
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Jian-xiong
authors.initials: JX
authors.lastname: Ma
authors.forename: Peng
authors.initials: P
authors.lastname: Tian
authors.forename: Chao
authors.initials: C
authors.lastname: Han
mesh_terms: D001863:Bone Screws; D006801:Humans; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome